SVArcturus

What mods to accommodate lithium battery bank?

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50 minutes ago, yl75 said:

Sure, but how does using Ah change anything to this aspect ?

It does not at all : this aspect is just inherent to what "typical discharge cycle" is used, and you will have different results whatever the unit used.

That is all I was saying, either unit will cause some inaccuracy in determining the actual energy delivered by the battery depending on the discharge cycle.

I have no idea which units are more useful, but noting that this aspect of the battery should not be ignored if proposing one vs the other. I suspect that using an energy unit is a more useful option.... but have nothing to back that up beyond my preference for using the 'right' unit :)

What matters is how useful the units used are to the user, not which one is more intrinsically 'right'.

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59 minutes ago, El Boracho said:

Um no. Not the same thing. Odd that people willing to adopt a new technology stick to the old mumbo-jumbo.

Perusing Ocean Planet Energy (one site that avoids mumbo-jumbo) it looks like my economic choices distill to this. Cruise plan is ten years away from centers of commerce. I.e. no typical dash from Tahiti to NZ to repair a boatload of failed crap.

LA: US$650 each 4 years. Utterly reliable, carefree and trivially easy to repair anywhere.

Carbon-Foam: US$1100 for some unknown longer periods. Almost as reliable as LA. Better performance. Easy to repair.

Self-contained Lithium: US$1700 for some very long period. Widely disparaged in the forum (?). Impossible to repair. Difficult replacement.

Lithium 'System': US$7000 and up for some very long period. High performance. Components likely to fail (users carry considerable spares). Complex diagnostics and repairs.

Looks like Carbon-Foam for me. Would consider self-contained Lithium but the reports do not instill confidence. One could plan on falling back to LA when a failure threatens to interrupt a pleasurable cruise. But that is the definition of a regrettable. 

 

 

I don't think you got the point of my post. I was talking about Wh vs. Ah.

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1 hour ago, El Boracho said:

?? Specifying a battery in W-h would be the honest and useful way. Unlike A-h, it assumes nothing about voltage.

I find it interesting that one of my confusions in trying to figure features and costs for the many and various Victron charger/inverter units ultimately turned out to be the fact that they spec the inverter as VA going in and Watts going out.  This, plus I had foolishly thought that VA=Watts.

IN ADDITION, it then turned out that depending on which dealer's adds you were looking out, some where giving the unit specs as VA (e.g., "Multiplus 12/2000/80/120", or 12V charger, 2000VA inverter INPUT, 80A battery charger, 120V input).  Another would, it turns out, show the same unit as 12/1600/80/120, with the inverter OUTPUT as watts.  The confusion was further because Victron also offers similar units with 1600VA input.

I understand the dealers were probably trying to offer the models in the terms that most of their audience used, but, in the day of internet advertising and sales, it makes for a massively confusing arena.

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15 minutes ago, SVArcturus said:

I find it interesting that one of my confusions in trying to figure features and costs for the many and various Victron charger/inverter units ultimately turned out to be the fact that they spec the inverter as VA going in and Watts going out.  This, plus I had foolishly thought that VA=Watts.

IN ADDITION, it then turned out that depending on which dealer's adds you were looking out, some where giving the unit specs as VA (e.g., "Multiplus 12/2000/80/120", or 12V charger, 2000VA inverter INPUT, 80A battery charger, 120V input).  Another would, it turns out, show the same unit as 12/1600/80/120, with the inverter OUTPUT as watts.  The confusion was further because Victron also offers similar units with 1600VA input.

I understand the dealers were probably trying to offer the models in the terms that most of their audience used, but, in the day of internet advertising and sales, it makes for a massively confusing arena.

I suppose VA is used so wire sizes and switches can be reliably specified. Always equal to W on the DC side.

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16 minutes ago, El Boracho said:

I suppose VA is used so wire sizes and switches can be reliably specified. Always equal to W on the DC side.

I was led to understand that the two are different because of energy losses in the inverter and that this difference was somehow presently a standard terminology.  So VA is apparently the "watts" going in and W is the watts going out, and the difference reflects the internal losses in inversion.

 

Wait, "always equal to W on the DC side".  Why not on the AC side?

Edited by SVArcturus

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12 minutes ago, SVArcturus said:

I was led to understand that the two are different because of energy losses in the inverter and that this difference was somehow presently a standard terminology.  So VA is apparently the "watts" going in and W is the watts going out, and the difference reflects the internal losses in inversion.

 

Wait, "always equal to W on the DC side".  Why not on the AC side?

Because of the phase shift between A and V (inductive loads)

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Ya, fun engineering stuff. There can be 2000VA “going in”. That is 16.7 A and 120 V as measured with a typical meter (RMS). But zero Watts. No load, no heat, no cost, no nothing. An undersized powercord would melt, for example. But if the load was a simple heater there would be no heat. So they say kVA instead of kW. Believe it. Fun stuff. 

Watts is for planning consumption costs, fuel burn, horsepower, etc. VA for wires and breakers.

Ampere-hours is like selling diesel by the square foot. Truly. A missing dimension. Ok if one knows the lingo. Should be Ampere-seconds for a purist....heh.

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7 hours ago, El Boracho said:

Perusing Ocean Planet Energy (one site that avoids mumbo-jumbo) it looks like my economic choices distill to this. Cruise plan is ten years away from centers of commerce......

LA: US$650 each 4 years. Utterly reliable, carefree and trivially easy to repair anywhere.

Carbon-Foam: US$1100 for some unknown............ 

"my economic choices..cruise.. ten years away from centers of commerce."

If it is economic choices you only base your decision on, then unfortunately your maths is wrong.

- For capital cost you have assumed "rated capacity" equals the same usable capacity between battery chemistries. They aren't.

- You have ignored operating costs over that 10 year period. 

- You have ignored total cost of ownership over that 10 year period.

- You have ignored cost per unit of energy consumed based on the above.

- You have ignored energy cost per person for their sustenance and comfort.

For instance whether they are forced to accept a diet of processed food or can always have fresh food as a source of strength and nourishment being away from those centres of commerce. Maybe a cold beer for mental wellbeing with cooling fan on hot days etc.

So many costs missing. You are clearly not frugal with your money, or worried about a standard of living over that 10 years. This is not good. 

PS. You say LA "easy to repair" How do you repair a faulty LA cell?

You say LFP System;  "Components likely to fail (users carry considerable spares) .  Complex diagnostics and repairs". Exactly what components fail and the evidence of this is where??

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VA=W but also recognises power factor, which is assumed to be a value of 1.0 for a VA rating. In simple terms, power factor is something that affects loads powered by AC circuits and any device with a power factor rating less than 1.0 will draw more instantaneous power at some point for every AC cycle than it actually consumes as an average. The closer to zero the power factor, the higher the ratio of instantaneous power to average power consumed by the load. Generators and inverters are typically output rated in VA as the power factor of the loads is - obviously - unknown for any given application. The catch is that for many generators and inverters this VA rating is also the absolute maximum rating beyond which the generator or inverter will be unable to supply even the additional instantaneous power requirement of a load with a PF <1.0. Stuff connected to the grid isn't so much affected as both the laws of averages and the use of power factor correction devices by the utilities minimise the affects.

 

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While I do understand the benefit of including the "loss" in inversion (or other areas where this is significant), a literal person like me would think that it would have been prudent to generate a different term than "VA"  when "VA=W" is one of those things they teach in high school (or maybe earlier).  I appreciate being able to assess the size of the inefficiency for a particular unit, just not the difficulty sometimes of telling *WHICH* VA and/or watt is being presented in a particular presentation of data.

I'm thinking this is one of those cases where those with expertise and lots of exposure know how to automatically correctly interpret what is said based upon the context around the statement.  Those without that "auto-correct" in place can easily be led astray.

But, I'm maybe getting there...

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5 hours ago, JohnMB said:

Because of the phase shift between A and V (inductive loads)

If you could elaborate a bit, are you saying VA does not equal watts in AC parlance, only in DC?  Or are you reiterating in somewhat different terms that the terms are used differently for incoming power than they are for outgoing power, despite the "definitions" being the same?

I'm really not trying to be difficult, I just have difficulty figuring out WHY terminology that seems to clash with long-standing definitions has become common use rather than a new term being created to address the differences.

On the other hand, its merely a gripe and I'm sure no one is changing the existing professional terminology, even if it does requires insider understanding. B)

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5 hours ago, weightless said:

Having trouble sleeping? This will help: https://en.wikipedia.org/wiki/Power_factor

That was useful, thanks weightless.

It didn't really resolve the need for terminology that doesn't lose the distinction on which aspect of the power is being discussed.  But, I'm sure the pros don't get lost in the apparent terminology conflicts and I'm now aware to "be aware" when reading performance specs.

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7 minutes ago, SVArcturus said:

I'm really not trying to be difficult, I just have difficulty figuring out WHY terminology that seems to clash with long-standing definitions has become common use rather than a new term being created to address the differences.

It's a long story. Maybe this summary will help: https://en.wikipedia.org/wiki/AC_power#Real_power

image.thumb.png.9f60581412385746c9b271ff93527858.png

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10 hours ago, El Boracho said:

...Odd that people willing to adopt a new technology stick to the old mumbo-jumbo.

Actually it is the other way around.

Two battery chemistries with vastly different internal resistances using the same Lead Acid 20 hour/10.5v rated capacity reference of Ah is complete nonsense. In fact it describes the "true" capacity of LFP whereas for LA it doesn't.

So the only reason rated capacity of LFP uses Ah was to make it backwards compatible to assist those who were more backward. :lol:

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5 hours ago, El Boracho said:

Ampere-hours is like selling diesel by the square foot. Truly. A missing dimension. Ok if one knows the lingo. Should be Ampere-seconds for a purist....heh.

Easily done... simply divide rated capacity by 72,000. Your 180Ah battery is now rated at 0.25As. Discussing how usefull that measure is may require a lot of alcohol. 

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13 hours ago, JohnMB said:

There is a slight twist with batteries in that unlike a fuel tank the battery itself is an energy sink, at high outputs it is a very significant energy sink. You need to account for this loss somewhere.

Well yeah, but Lead-acid has standardized (for the most part) on a 20-hour delivery/run down time. So a 200 Ah battery should deliver 10Ah/hour for 20 hours and reaching 100% depletion. It's a bit of a fudge, of course, because every L-A battery has a different Peukert number and if you to a 10 hour or 5 hour drain-down you'll get a different number of amps counted.

LFP has a much tighter range of efficiencies, and high C loads do not have the same inefficiencies they do with L-A.

So the 20 hour "Amp-hour" is sort of a sloppy benchmark to standardize on. But ultimately, it's STILL more clear than using watts, I think, as long as we're using nominal voltages as well.

Why?

Because as charge drops with a constant current drain, so does voltage. And so, therefore, does wattage. So Amps X Voltage will vary over time, and not give you a consistent total.

But one can convert the nominal voltage (12V) and the 20 hour amperage to get a useful apples-to-apples comparison between batteries for the most part, and that helps.

So my 720Ah, 24V house bank can be referred to as 17,280 Watts. But is it truly accurate when the measured voltage at the moment (at 50% DoD) is 26.00V?

At the end of the day, the unit we count and use is cumulative current over time, and that load should be reasonable constant for a given device. At least for planning and capacity purposes, you can only be so precise. If the nominal is unknown, it should be specified if relevant.

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2 hours ago, jack_sparrow said:

Actually it is the other way around.

Two battery chemistries with vastly different internal resistances using the same Lead Acid 20 hour/10.5v rated capacity reference of Ah is complete nonsense. In fact it describes the "true" capacity of LFP whereas for LA it doesn't.

So the only reason rated capacity of LFP uses Ah was to make it backwards compatible to assist those who were more backward. :lol:

I don't know, most to the doo-dads on my boat have Ah ratings on them, except the oddball household AC appliances.

Then again, I've always thought of consumption Ah, even though I grok Watts they didn't seem any more useful to me.

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6 hours ago, jack_sparrow said:

"my economic choices..cruise.. ten years away from centers of commerce."

If it is economic choices you only base your decision on, then unfortunately your maths is wrong. .... So many costs missing. You are clearly not frugal with your money, or worried about a standard of living over that 10 years. This is not good.

- I made an effort to compare systems with similar energy storage capacity. Chose the closest matches from each solution. I am well aware of the energy capacity limitations of LA. Though I do work them hard...no mercy.

- I did not ignore operating costs. I clearly included a planned replacement cycle for the LA. Not sure what other cost there is. Distilled water?

- I assume my variable cost of energy is zero. Some certainly comes from the diesel. I do not readily know how much. But I do know it is small enough to be safely ignored as the difference in charge efficiency would be a minuscule difference in cost for me.

- The energy consumption per person? You got me there. Two people, as always. I have no idea of total consumption. The 225 A-h LA bank is run down pretty low by morning. 50 to 70 DoD wouldn't be surprising especially if the previous day was cloudy.

- We have been cruising widely for many years. 10 on this luxury yacht and about 6 on the previous tub. We want of nothing during our cruises. Largely because of my wife's of-the-earth culinary skills. We buy no canned food except at the ditch-bag level. Hmmm, the filipina sometimes splurges on SPAM...

In summary, I don't see how I have missed describing any costs. Admittedly the frequency of unexpected repairs is unknown. I do know that such repairs increase in proportion to complexity and component costs.

- LA is easy to repair because firstly the diagnostics are trivial. Secondly, the one critical component unique to LA is the battery itself which is widely know to be extremely reliable. In all my years of autos, tractors boats and remote power systems I cannot recall an unexpected failure of a single LA cell. Third, such LA batteries are widely available. Have renewed them in various places. Poor temporary replacements even more available...but never done that. Actually a LA cell can be jumpered out of the battery with self tapping screws, but a 10 V system is largely useless.

- I obtained my lithium failure, repair and spares facts from experienced people in this very thread.

- The same for complexity. This very thread contains considerable complex discussions of issues.

If accounting of costs is important one should include the lost opportunity costs of extraordinary capital investments. If history is a guide my lost opportunity cost of sinking an extra US$5000 into a fancy battery system for ten years would well beyond US$50,000. That is a real issue for me.

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3 hours ago, jack_sparrow said:

Easily done... simply divide rated capacity by 72,000. Your 180Ah battery is now rated at 0.25As. Discussing how usefull that measure is may require a lot of alcohol. 

Ooops...I'm sure you meant 180 A•h would be 648,000 A•s. But people should make some effort to accept SI units when discussing technical things: 7.78e6 Joule or 7.78 MJ (megajoule). A Joule is a Watt•second. 3600 J is a Watt•hour.

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On 7/26/2020 at 3:51 PM, 2flit said:

And.... I had asked "What went wrong and how bad did it get?" (with bottom balancing)... You didn't mention any failures related to bottom balancing? Maybe you could elaborate on your experience using bottom balanced prismatic cells in marine discharge scenarios?   

On 7/26/2020 at 5:34 PM, jack_sparrow said:

I've said bottom balancing is NOT the domain of fractional C use in sailboat applications. I've said bottom balancing IS the domain of high C use like in electric vehicles and maybe off-grid applications....

....Why would I therefore employ a method that raises the probability of problems? Maybe a better question of me is why top, not bottom balance if you disagree? That gives you something to interrogate. If you answer that voltages question I will try and weave that in.

 

On 7/28/2020 at 9:03 AM, 2flit said:

We have never gone below a 75% DOD  (unless cap testing) usually discharge is less than 25% DOD before recharge. ...

...You now mention high (voltage SOC) here..., because we are bottom balanced, we never charge the last 10% unless I am checking the individual cell balance. 

...True with all batteries and especially with our  Lithium topology where eddy currents could develop ..

 ...Our bank has been sized in such a way (and C/C configured in such a way) that we have never enter this region of the curve... 

 

On 7/28/2020 at 7:10 PM, jack_sparrow said:

2flit I will give you one thing.

You were smart enough to realise I was onto you, hence you constantly refused to answer my questions on what your set point voltages were.

So the only way you can operate LFP WITHOUT a BMS and have NO issues is you are are ONLY using around 60% of your CALB banks rated capacity between recharges. 

That's barely better than sealed LA. 

That's pretty fucking funny :lol:

 

So snapshot of 2flit avoiding revealing his set point voltage .....the gig is up and why. Then back to this and some housekeeping. 

On 7/27/2020 at 6:11 AM, 2flit said:

"There will be exceptions to the above where users preach no issues .....until it happens to them of course. In my experience it always does."  Are you actually suggesting that I am preaching?   I sincerely apologise if I did,    that’s my bad.

It would help to know, Anyone… did I sound preachy?

Preachy ...no ...you are not sorry. You know have been lying. You have been caught out. That is why you have now dissapeared. 

The housekeeping 2flit is now to clean up after your mess to avoid people getting mislead.

Your claim of "bottom" balancing of cells at time of pack building was what kept your system in balance. Complete horseshit.

It is clear 2flit's your operation of staying well short of the "hockey stick" ends and "knees" on them sticks when both discharging and charging is keeping your cells in balance. It has NOTHING to do with the balancing technique you selected, in fact it is the exact OPPOSITE to what you say your operation is.

2flit I know you are pissed at me pissing on your LFP No BMS parade. This might save you a lot of pain.

You are at greater risk of greater cell imbalance because you say you go within 10% at TOP charging end, but 25% clear at BOTTOM discharging bottom end. But you subscribe to bottom balancing. The OPPOSITE applies. See balancing below.

Our bank has been sized in such a way (and C/C configured in such a way) that we have never enter this region of the curve..."

On 7/28/2020 at 9:03 AM, 2flit said:

There is a hockey stick curve at the top and bottom of the charge/discharge. Our bank has been sized in such a way (and C/C configured in such a way) that we have never enter this region of the curve

Bizarrely you even say LFP is more at risk at the top end. "True with all batteries and especially with our Lithium topology where eddy currents could develop"

On 7/28/2020 at 9:03 AM, 2flit said:

True with all batteries and especially   with our Lithium topology where eddy currents could develop..  

I have not run individual cell capacity tests but have run another rare capacity test recently on the entire assembly. It seems steady at about 102% of rated capacity. It is too difficult aboard a sailing vessel for me to do individual cell capacity tests.

Furthermore you say bottom balancing as a operation is a pain in the arse and admit that re absence of doing cell capacity testing on board.

I'm sorry 2flit but if are claiming 102% of rated capacity on a pack basis presumably measured using a shunt or induction loop BUT YOU SAY you are not seeing cell drift ...then you are lying. Pure simple. This is the spec of you cells. I only use CALB cells, so know them well.

2flits CALB 100 Discharge Curve

IMG_20200730_163546.jpg.662ace57562eb93e2308002398c3cda6.jpg

Mate you are on a mission and willing to post bullshit and withold information plus claim you are not an "outlier."

On 7/28/2020 at 9:03 AM, 2flit said:

I think I have been called an 'outlier' and I feel it is incumbent on me to report back to you if or when even the slightest issue arises.

I'm sorry but you are a lying prick pure and simple trying to justify your approach. I don't have a issue with your approach as long as you are honest about it.

You weren't and still aren't. 

______________________________________

Anyway to be clear for anyone reading this shit of mine.

The price of 2flit having no BMS is having battery cells operating at ONLY around 60% of their rated capacity. My bet it's getting worse. His admission checking having to check cell voltages a givesway.

It is why he has installed 400Ah "rated" capacity at 12v but "actual" capacity of only around 240Ah by having no BMS. Double that if repeated elsewhere to 16 cells shown on DWG below. For a 40' foot Tri with one small auxilliary as the largest non AC charge source, that probably works well. But it is hardly one taking advantage of LFP, justifying cell expense, or one for justifying having no BMS. A sham promoting it.

2flit Instalation using CALB C100 cells 

P1030403.JPG.873a979be8b88223148e954a40a7ccf2.jpeg.ad1a752d63a7dc8bf5f86326d51de235.jpegIMG_20200730_144715.jpg.3ab5e7b79c57585296c897565bbe93c4.jpg

Now to why I posted then got angry about 2flit's propoganda and got diverted....sorry.

The useful bit of this post. 

Balancing

A 12v LA battery has typically 6 cells. A 12v LFP pack assembly typically 4 or 8 and will not recover from an extreme under or over voltage event. I mean dead fucking expensive door stop dead. Balancing helps avoid that.

The convention of "top" balance for fractional C marine use and "bottom" balance at high C rates like Electic Vehicles is relatively easy to explain. Also balancing is no secret art. It should be a "once off" done when assembling the pack to match the cells for internal resistance and Ah capacity. If you still have balancing problems your system purchase assembly etc is shit. Don't blame the chemistry. 

With a properly featured BMS, it is doing this balancing (simply in effect a resistor V transfer to heat) at low currents (ie. charging at high V low C above 95% SOC) but not if drift is large caused by a prior episode or incorrect initial balance. If you haven't got well matched cells to start with then no BMS can keep them in balance at voltage extremes. Best not go there chasing that last bit of capacity.

Top Balance.

A top balance is cells balanced at the HIGHEST “safe” voltage where all cells will converge and match exactly at say 3.5v per cell.

Sailboats are unique. The loads are not high at least for extended periods, there are frequent opportunities to charge and infrequent opportunities to completely drain the bank. That is because they have multiple charge sources on hand some 24/7.

I'm not by any means extreme for a 50 plus footer having AC shore, AC generator, engine alternators (2), hydro alternator and solar controllers. Others have more or different configurations, maybe the exotic like hydrogen fuel cells.  

So for sailboat LFP users the risk of cell imbalance is MORE pronounced at the TOP charging end, rather than discharging at the bottom end. A RV with LFP has similiar use and opportunities/constraints to a sailboat. 

Bottom Balance. 

A "bottom" balance is cells balanced at the LOWEST “safe” voltage where all cells will converge and match exactly at say 2.75v per cell.

A "bottom" balance is suitable for the exact opposite to what occurs on a sailboat or RV. High loads, where there are frequent opportunities to drain the bank and infrequent opportunities to charge. 

An Electric Vehicle (EV) has high loads, frequent opportunities to discharge to a critical voltage and infrequent charging opportunity is only when garaged and then charged with one, very controlled charge source. An EV battery pack is therefore  tailor made for "bottom" balancing.

IMO the sailboat and off-grid user are more closely aligned than off-grid and EVs. That is an argument I have no interest in. However interstingly the bottom balancing off-griders are becoming less vocal/disappearing as they realise generic LVP literature/forums in LFP's more formative years this last decade, led them up the wrong balancing path. 

I mention this as I have a strong feeling 2flit reading the LFP theory and not listening to sailboat people about LFP this last decade is his problem. He commissioned in US and left going west 3 years ago. He is stuck with what he has good or bad.

No problem with that. But when he starts pushing his bull shit applying no caveat, it's open season.on bullshit.

 

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10 hours ago, jack_sparrow said:

PS. You say LA "easy to repair" How do you repair a faulty LA cell?

You say LFP System;  "Components likely to fail (users carry considerable spares) .  Complex diagnostics and repairs". Exactly what components fail and the evidence of this is where??

3 hours ago, El Boracho said:

LA is easy to repair because firstly the diagnostics are trivial. Secondly, the one critical component unique to LA is the battery itself which is widely know to be extremely reliable. In all my years of autos, tractors boats and remote power systems I cannot recall an unexpected failure of a single LA cell. 

 

3 hours ago, El Boracho said:

- I obtained my lithium failure, repair and spares facts from experienced people in this very thread.

 

Fabulous stuff... I could go on for years like about starting a Nufield tractor with a cartridge ...then driving when 8 yo ...but you didn't answer the question. 

Your claim is you can "repair a faulty LA cell"

Your no fault LA cell history is irrelevant. Question/Answer is how do you repair that LA cell? We both know the answer don't we.:lol:

Then the question how do repair a LFP cell? Ogh by God you can replace them :o :lol:

Then your claim that your lithium failure, repair experience etc is resticted to this thread. 

Easy then.. stop fucking around posting  shit you admit you know nothing about and quote those posts, OR piss off about that aspect unknown to you.

Take your pick.one or the other.... its binary and stop being a smart cunt.

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9 hours ago, B.J. Porter said:

Well yeah, but Lead-acid has standardized (for the most part) on a 20-hour delivery/run down time. So a 200 Ah battery should deliver 10Ah/hour for 20 hours and reaching 100% depletion. It's a bit of a fudge, of course, because every L-A battery has a different Peukert number and if you to a 10 hour or 5 hour drain-down you'll get a different number of amps counted.

LFP has a much tighter range of efficiencies, and high C loads do not have the same inefficiencies they do with L-A.

So the 20 hour "Amp-hour" is sort of a sloppy benchmark to standardize on. But ultimately, it's STILL more clear than using watts, I think, as long as we're using nominal voltages as well.

Why?

Because as charge drops with a constant current drain, so does voltage. And so, therefore, does wattage. So Amps X Voltage will vary over time, and not give you a consistent total.

But one can convert the nominal voltage (12V) and the 20 hour amperage to get a useful apples-to-apples comparison between batteries for the most part, and that helps.

So my 720Ah, 24V house bank can be referred to as 17,280 Watts. But is it truly accurate when the measured voltage at the moment (at 50% DoD) is 26.00V?

At the end of the day, the unit we count and use is cumulative current over time, and that load should be reasonable constant for a given device. At least for planning and capacity purposes, you can only be so precise. If the nominal is unknown, it should be specified if relevant.

"So my 720Ah, 24V house bank can be referred to as 17,280 Watts."

Wh not Watts ! (watt is a power unit, not an energy unit)

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7 hours ago, jack_sparrow said:

Fabulous stuff... I could go on for years like about starting a Nufield tractor with a cartridge ...then driving when 8 yo ...but you didn't answer the question. 

Your claim is you can "repair a faulty LA cell"

Your no fault LA cell history is irrelevant. Question/Answer is how do you repair that LA cell? We both know the answer don't we.:lol:

Then the question how do repair a LFP cell? Ogh by God you can replace them :o :lol:

Then your claim that your lithium failure, repair experience etc is resticted to this thread. 

Easy then.. stop fucking around posting  shit you admit you know nothing about and quote those posts, OR piss off about that aspect unknown to you.

Take your pick.one or the other.... its binary and stop being a smart cunt.

Are you going to shift the entire discussion to repairing cells? Hanging by a thread, your rant is.

I would repair a failed LA cell by replacing the battery. Seems like exactly the same method a failed Lithium system would be repaired upon the failure of a single transistor among the millions in a BMS module: Replace all 2 billion transistors in the module like I would replace all 3 cells of a T-105. Easy to obtain, but also only a few hundred bucks and 28 kg to carry a spare.

I think I am following an honest and rigorous process in choosing my next battery system. Nor have I been attacking anyone. What is your point? You could make your case for economy, reliability, ease of diagnostics, ease of repair.

I did not actually say my knowledge and evidence is restricted to this thread, but that this thread has been a bountiful source. I've been watching the lithium tech for many years.

Just a reminder. I am not tech adverse. No fan of the ancient LA technology. And is there something bad about a cunt I should know about? 

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On 7/24/2020 at 3:53 PM, 2flit said:

I am skipping a BMS because they cause more problems than they solve. Not to save money. I love my trimaran and spend money  like a drunken sailor. on her.  It has  absolutely zero to do with saving $$$ 

The ONLY real world LiFePO4 fire (actual LiFe  battery fire in the real world and not some demo on the internet)  that I have been made aware of was caused by the Battery Management System (BMS)!    I am not talking about Cobalt Lithium, I would not go anywhere near that fire trap. This is Iron chemistry we are talking and real world applications. I have 10 KW inverters running on a single string of these cells for two years now with ZERO issues. I care about my safety and have done the field work.  I have over 33 years experience installing power systems and am no fool.

Your batteries are crashing because they were never bottom balanced. Never having done had this, they just get more out of equilibrium as time goes on. You are dependant on your BMS because of how the batteries were assembled without individual bottom balancing.  It is not essential  to have a BMS and my 3 years of use proves this as has the 100's of other installs out there that do not have a BMS.  

Nope.

I mean, if you use lousy electronics, then of course you get lousy results. BMS are not expensive or complicated devices prone to failure.

To have a safe system, proper engineering is required, and that takes time and money and discipline. 

The battery company I selected was founded and is run by a Caltech PhD. To get his degree, he had to demonstrate tremendous skill and discipline in the laboratory. He approached the problem scientifically: he bought a bunch of different kinds and numbers of cells, and did extensive testing including to destruction. It is necessary to destroy a bunch of cells to learn anything at all, because the edge cases are what lead to fires and other less critical failures. 

The DIY efforts are about saving money, so I will wager you did not destroy a large number of cells when you built your bank, but just depended upon other people's work, especially the data sheets. Do you have any idea what the error bars are on the data on the data sheets? My guy knows, so I went with him rather than do the engineering sufficient for safety and longitivtiy on my own. 

Yet again, since my batteries are 12v and I need a 48v bank, the BMS within the batteries was not sufficient, and I had to add a balancer to make the bank of batteries remain stable. Essentially a BMS for the system on top of the BMS for each 12v unit.

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On 7/24/2020 at 5:49 PM, SVArcturus said:

 If I understand correctly, their BMS basically just shuts the battery down if the voltage is too high or too low.  Not much else happening there.

While that may be the case, all the units that I know of that are called BMS do two things: 1) actively transfer current from cell to cell to minimize voltage difference across the cells, thereby providing maximum available energy and cell life, and 2) switch off the entire set of cells if the voltage is too high or low.

In my case, where I had to create a bank from multiple independent boxes each containing a BMS and several cells, I had to add the battery balancer that does step (1) above, and I depend upon the BMS within each box to minimize inter-cell voltage and provide the over/under voltage protection to avoid fires onboard.

The approach iStream used is to be commended (back on the first page of this discussion), and will soon be pervasive as such CANbus enabled (and Bluetooth enabled) inter-BMS networking is becoming widespread.

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On 7/24/2020 at 6:43 PM, Raz'r said:

Crazy right? I’m looking at going through and cutting off bolts sitting proud. Pulled a bunch of 14 gauge cable and replacing with 18 and 20. Engine driven reefer with a little solid state compressor. All lights with LED. SSB with satellite. But damn if I can’t get my head around this one. Why? Cause all the elect engineers and techs argue. Over and over, no consensus on what works. I’ve splurged a bit and have the carbon/foam batteries and went with the Sterling alt-to-battery controller. AGM charge profile for the house and the little auxiliary 12AH backup battery required for racing. (Yes, I start the engine off the house.)
 

i think I’ll just pull one battery off for the TPac next year. 2/3rds the weight savings. No cost.

 

Raz'r, I like your approach.

This is early in the process, we are early adopters. Probably by the time you are ready to replace your LA batteries, its going to be much simpler and more reliable.

Individual experience is rarely supported by sufficient testing across the life cycle and available cells. This is too soon for simple "research" of just reading what others write.

Hence,  I depended upon a true scientist to do the EXPENSIVE scientific work that is ignored in typical DIY efforts. For the expensive part of the system -- the LiFePO4 cells -- I depended upon someone who burned up a LOT of cells from many vendors to discover what actually worked well and why. Interesting, he found that the prismatic (rectangular cube) cells are cheaper on a unit basis, but much more expensive over the life time of the cells. The cylindrical ones are just that much better in fact. The paperwork does not suggest this to be the case, but by spending a LOT of money on cells, and a LOT of time on life cycle testing, both for nominal performance and taking things to the edge, the guy I bought my batteries from actually knows what he is talking about, authoritatively. I believe him. He has the data to back it up, not just observations of one or a small number of units that have been used in unknown performance envelopes. Engineering at the leading edge is hard and expensive. I paid about twice as much as I could have bought raw cells. However, the engineering behind my batteries burned up many times more than the number of cells I own, so I saved a million dollars and a couple of years of time when the engineering is included. And, if I just buy cells, I can still only tell what is written in the ad, and nothing at all about the actual performance from the actual vendor, and how to tell if the cells provided are actually meeting any reasonable spec or standard.

Yet even then, I did have problems with the complete system that did take over a year to sort out. Now, the system works well.

But I only charge at the dock: proving out the regeneration is waiting on a prop change at the next haul out; figuring out solar is a whole 'nother issue.

Last weekend, we spent 4.5 days off of shore power, used the electric motor twice as much as usual, and returned with 48% State of Charge. We use a new but typical 12v compressor for our poorly insulated fridge, only LED lighting, only digital communication, lots of USB charged devices including computer, iPads, iPhones, etc. About the same energy on USB charging as the refer. I was working aboard, and we were watching movies, so the USB recharged devices did get heavily used.

On a race boat, a big benefit is how quickly they charge: run that engine once a week for an hour instead of an hour per day. Of course, after you do all the other stuff, as you mentioned!

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37 minutes ago, carcrash said:

In my case, where I had to create a bank from multiple independent boxes each containing a BMS and several cells, I had to add the battery balancer that does step (1) above, and I depend upon the BMS within each box to minimize inter-cell voltage and provide the over/under voltage protection to avoid fires onboard.

Thanks for sharing first hand experience.  Any chance you can elaborate on what you installed as a battery balancer for the 48V system you have.    

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34 minutes ago, yoyo said:

Thanks for sharing first hand experience.  Any chance you can elaborate on what you installed as a battery balancer for the 48V system you have.    

Here is the balancer I bought. 

https://www.amazon.com/Battery-Equalizer-48V-Voltage-Balancer/dp/B07L8WKKC3/ref=sr_1_3?dchild=1&amp;keywords=battery+balancer&amp;qid=1596140397&amp;sr=8-3

 

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Thanks - so if I read this correctly it maintains battery balance during both draw down or charge.   Sounds like that should have fixed issues you discussed in another thread.

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9 hours ago, yl75 said:

"So my 720Ah, 24V house bank can be referred to as 17,280 Watts."

Wh not Watts ! (watt is a power unit, not an energy unit)

No, it's Watts. Wh implies a time component to it.

In theory my battery bank can deliver 720A of total current at 24V nominal from fully charged to fully discharged. That is the sum total of POWER in the bank. It doesn't matter if it's coming our at -5A or -120A. The total watts delivered will be 17,280, whether it takes six days to drain it or six hours.

How much is actually coming out will, of course vary with time and load because of inefficiencies in the batteries, resistance in the cabling, etc. etc.

But (rated capacity x nominal voltage) represents all power in the battery and has nothing to do with time.

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4 hours ago, carcrash said:

The approach iStream used is to be commended (back on the first page of this discussion), and will soon be pervasive as such CANbus enabled (and Bluetooth enabled) inter-BMS networking is becoming widespread.

More CANbus enabled BMS's is good in theory until you look at say marine quality charger/inverter offerings where their CAN is proprietary to lock people into their LFP system offerings.

Victron an example BUT they do still provide programmable HV and LV analogue pack voltage inputs as a work around. If they stop doing that and still retain proprietary CAN life then gets difficult.

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7 hours ago, El Boracho said:

I would repair a failed LA cell by replacing the battery. Seems like exactly the same method a failed Lithium system would be repaired upon the failure of a single transistor among the millions in a BMS module: Replace all 2 billion transistors in the module like I would replace all 3 cells of a T-105. Easy to obtain, but also only a few hundred bucks and 28 kg to carry a spare.

I have 32 cells in my LiFePO4 battery. You can see them all in that picture.

If I have a critical failure in a cell, I can procure one single cell (currently $230 or so) and replace it. It's 1/32 of my battery capacity.

If it dies in the field, say at an anchorage in Vanuatu, I can get out my wrenches and reconfigure the battery to a 3P8S configuration on the spot without leaving my boat and keep going with a 540Ah bank instead of 720Ah. I'm running again then, and can keep cruising until I go to wherever my replacement cell is waiting for me.

Can you "repair" your T-105 the same way if it fails? I doubt it. You will need to procure a replacement on shore and bring it to the boat to install it.

Any LFP bank with more than four cells will have this built in redundancy to make a safe limp-back mode out of it. Though "limp-back" is relative, because in my case it is still almost double the usable capacity I had with 6 AGM batteries filling every spare inch of space in my battery box.

This is what my BMS looks like. It's dimensions are 97.4 x 30 x 54.5 mm, or 3.75" x 1.25" x 2.15".   It is a $3-400 dingus, true, but it's similar in volume to a deck of cards. It's not a difficult item to keep as a spare, in other words.

If done properly, you've configured your BMS, taken a backup of the configuration, and restored that copy into your spare BMS. So replacing it involves unhooking a ribbon cable and loosening two screws to dismount it, then popping the new one in and attaching the cable. If you've not prepared ahead of time, you will have to plug a laptop in and configure it or restore it.

emus_bms.thumb.jpg.e354077e2400686661508ba3e826a324.jpg

Yes, there are other components. But they are not difficult to replace, keep on hand, or just bypass if there's a failure.

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Just now, jack_sparrow said:
4 hours ago, carcrash said:

The approach iStream used is to be commended (back on the first page of this discussion), and will soon be pervasive as such CANbus enabled (and Bluetooth enabled) inter-BMS networking is becoming widespread.

More CANbus enabled BMS's is good in theory until you look at say marine quality charger/inverter offerings where their CAN is proprietary to lock people into their LFP system offerings.

Victron an example BUT they do still provide programmable HV and LV analogue pack voltage inputs as a work around. If they stop doing that and still retain proprietary CAN life then gets difficult.

This is true^^. LFP CANBus will get much better if (or when) the marinized charger people open their APIs to third party BMS makers. I'd love to run CAN to my Victron chargers so my BMS could take better control of the charge cycle again.

Another thing my BMS does with CAN that it can't so so well with non-CAN is deal with temperature and low charge scenarios. In the event off a too-deep cell voltage or a too-low ambient temperature, the BMS will automatically shift the charger to a "warm up" mode to start the charging with a greatly reduced current to raise the ambient temperature and increase the cell voltage to safe levels slowly before slamming in the full charge current. It's just another level of protection.

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3 hours ago, carcrash said:

The fellow who sold me my BMS and helped me spec and design the system recommended several devices like that, so I bought them. Since they were supposed to keep the cells in balance, right?

After a while (over a year so), the cells moved out of balance. Far enough that one cell was keeping me from getting a full charge, and others were keeping me from getting a full discharge. So I broke up my bank, charged each cell to 3.5V with a bench charger, and put it all back together again.

Now, almost a year and a half later, my cells without the external balancers, are all within +/- .01V of each other all the time.

When we were designing this system, I wasn't certain what the external balancers were supposed to do that the BMS couldn't. They sounded sort of like snake oil to me, but I trusted the recommendation of the BMS guy since he'd done these systems before.

Now...they do seem like snake oil, and during and after the install I learned that the BMS guy made several poor recommendations, or recommendations that were against my best interest because they were advantageous to his business needs, not my technical ones.

So to me, they were money wasted since the cells got way out of balance with them, and have stayed in balance with using the BMS cell balancing capability only.

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1 hour ago, B.J. Porter said:

No, it's Watts. Wh implies a time component to it.

In theory my battery bank can deliver 720A of total current at 24V nominal from fully charged to fully discharged. That is the sum total of POWER in the bank. It doesn't matter if it's coming our at -5A or -120A. The total watts delivered will be 17,280, whether it takes six days to drain it or six hours.

How much is actually coming out will, of course vary with time and load because of inefficiencies in the batteries, resistance in the cabling, etc. etc.

But (rated capacity x nominal voltage) represents all power in the battery and has nothing to do with time.

This is confusing,

You said your battery can deliver 720Ah  (note the h) earlier.  POWER is instantaneous VI so if it coming out at 5A and 24V then you are getting 120W if its coming out at 120A then you are getting 2880W.  

You are getting 1780Wh (watt hours) whether you are at 5A (and 120W) or 120A (and 2880W).  Rated capacity is in ampere hours (Ah) not in amperes. (A)

W (Watts is an instantaneous measure of Power)  (Energy/time), Wh is a measure of Energy,

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8 hours ago, El Boracho said:

Are you going to shift the entire discussion to repairing cells? Hanging by a thread, your rant is.

I didnt shift at all. It was you NOT me who applied repairability against each chemistry. I only responded. Rant maybe, but you keep repeating things which are wrong, as noted below. 

8 hours ago, El Boracho said:

I would repair a failed LA cell by replacing the battery.

I would repair a 3.2v LFP cell by replacing ONLY that 3.2v cell NOT the entire LFP battery. You don't have to even carry a spare cell. Just carve out some cells and lose 25% capacity only. That is a big repairability/redundancy difference between LA and LFP.

8 hours ago, El Boracho said:

Seems like exactly the same method a failed Lithium system would be repaired upon the failure of a single transistor among the millions in a BMS module: Replace all 2 billion transistors in the module like I would replace all 3 cells of a T-105. Easy to obtain, but also only a few hundred bucks and 28 kg to carry a spare.

LA no BMS big advantage over LFP.

BMS failure carry spare BMS (small in size and relatively cheap plug and play ready)  and or configure 2 LFP banks with 2 BMS's where one BMS still has the capacity to control 2 banks. That 2 not 1 redundancy platform sitting there.

There is redundancy in LFP, just need to think it to find it. 

8 hours ago, El Boracho said:

I think I am following an honest and rigorous process in choosing my next battery system. Nor have I been attacking anyone. What is your point? You could make your case for economy, reliability, ease of diagnostics, ease of repair.

You may be following a process but without nominating your charge sources and loads I can only comment upon what information you furnish here. If it includes a view of LFP which is wrong, as I have just pointed out, I will do so. 

8 hours ago, El Boracho said:

I did not actually say my knowledge and evidence is restricted to this thread, but that this thread has been a bountiful source. I've been watching the lithium tech for many years.

Again I can only comment upon what you say. You said your knowledge of LFP failures came from this thread. If your knowledge came from elsewhere then with regard to LFP repairability/redundancy it was wrong, as I have just pointed out.

19 hours ago, El Boracho said:

I obtained my lithium failure, repair and spares facts from experienced people in this very thread.

I believe I have probably been the one who has pointed out more potential and credible LFP failures on this thread than anyone, from my own experience. Then furnished the solution. 

Finally

8 hours ago, El Boracho said:

Just a reminder. I am not tech adverse. No fan of the ancient LA technology. 

I don't think you are tech adverse, just prejudiced with regard to LFP, which would only appear to be from ignorance.  :DHence my hope you are now better informed by my comments. 

BTW while you may not be a fan of ancient LA technology it may well be your best bet and my guess if I knew the detail of your opportunities/constraints and usage would probably agree with you. As I've noted upthread I have talked around half of people who contact me out of going LFP, sending some even backwards to flooded LA.

Cheers.

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16 minutes ago, JohnMB said:
1 hour ago, B.J. Porter said:

No, it's Watts. Wh implies a time component to it.

In theory my battery bank can deliver 720A of total current at 24V nominal from fully charged to fully discharged. That is the sum total of POWER in the bank. It doesn't matter if it's coming our at -5A or -120A. The total watts delivered will be 17,280, whether it takes six days to drain it or six hours.

How much is actually coming out will, of course vary with time and load because of inefficiencies in the batteries, resistance in the cabling, etc. etc.

But (rated capacity x nominal voltage) represents all power in the battery and has nothing to do with time.

This is confusing,

You said your battery can deliver 720Ah  (note the h) earlier.  POWER is instantaneous VI so if it coming out at 5A and 24V then you are getting 120W if its coming out at 120A then you are getting 2880W.  

You are getting 1780Wh (watt hours) whether you are at 5A (and 120W) or 120A (and 2880W).  Rated capacity is in ampere hours (Ah) not in amperes. (A)

W (Watts is an instantaneous measure of Power)  (Energy/time), Wh is a measure of Energy,

OK, if that's what keeps it clear for you.

I've never heard anyone, ever, refer to a "Watt-hour" capacity for a battery bank, it's always either Ah or just Watts. And usually it's Ah in coversation because that's what we're used to speaking about, but since mine is a 24V bank I always have to mention that in discussion since 24V is still fairly uncommon. Watts generally only comes up when people are trying to compare sizing between battery banks with different voltages.

But that's more of a language shorthand thing and certainly may be less technically correct.

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25 minutes ago, B.J. Porter said:

OK, if that's what keeps it clear for you.

I've never heard anyone, ever, refer to a "Watt-hour" capacity for a battery bank, it's always either Ah or just Watts.

Because many of the early adopters are kinda hackers.

A•h multiplied by a voltage gives (A x V) • hours. Product of current and voltage is Watts. So W•h it is. 

Like I said upthread: Stating Amp-hours is kinda like selling diesel fuel by the square foot. Rather begs the question of "How deep?"

If your "deliver 17,280 Watts" you are going to have a fire on-board. :D

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1 hour ago, Fiji Bitter said:

 

Pretty amazing when you think we have more computing power in our cell phones than what those guys had...plus we don't have a shred of bakelite. :lol:

Actually our sailboats probably have more computing power than Houston had.

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27 minutes ago, B.J. Porter said:

OK, if that's what keeps it clear for you.

I've never heard anyone, ever, refer to a "Watt-hour" capacity for a battery bank, it's always either Ah or just Watts. And usually it's Ah in coversation because that's what we're used to speaking about, but since mine is a 24V bank I always have to mention that in discussion since 24V is still fairly uncommon. Watts generally only comes up when people are trying to compare sizing between battery banks with different voltages.

But that's more of a language shorthand thing and certainly may be less technically correct.

I have never heard of watt hours either, just makes my head sore seeing watts being used for energy :), that's just plain wrong.

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2 minutes ago, JohnMB said:

I have never heard of watt hours either, just makes my head sore seeing watts being used for energy :), that's just plain wrong.

I've heard of them, but I've just never used them conversationally.

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40 minutes ago, jack_sparrow said:

Pretty amazing when you think we have more computing power in our cell phones than what those guys had...plus we don't have a shred of bakelite. :lol:

Actually our sailboats probably have more computing power than Houston had.

Heck, if I recall correctly, I had more power in my Apple II+ in 1981 than they did (on the spacecraft itself anyway).  And I had the "biggest" version with all of 48k of RAM. 

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2 hours ago, B.J. Porter said:

OK, if that's what keeps it clear for you.

I've never heard anyone, ever, refer to a "Watt-hour" capacity for a battery bank, it's always either Ah or just Watts. And usually it's Ah in coversation because that's what we're used to speaking about, but since mine is a 24V bank I always have to mention that in discussion since 24V is still fairly uncommon. Watts generally only comes up when people are trying to compare sizing between battery banks with different voltages.

But that's more of a language shorthand thing and certainly may be less technically correct.

Wow ... , again Watt is a power unit, like the number of hp of your engine (1 kW = 1.34 hp), not an energy unit !

Would you use hp to describe the number of gallons of your fuel tank ? (multiplied by the energy density of one gallon of diesel if you want) 

And Wh or kWh are of course routinely used for batteries, for instance :

Quote
Battery 100 kWh lithium ion
60, 70, 75, 85, 90 kWh discontinued

https://en.wikipedia.org/wiki/Tesla_Model_S

Or :

Quote

The current Model S would require 19 of these to reach its 100kWh capacity. If you multiply this out from the single-unit cost, that’s £27,360 ($34,500) in total. In other words, over a third of the price of a Tesla Model S could be just the cost of the batteries. More modest, entry-level EVs nowadays still have at least 40kWh (such as the basic Nissan Leaf), and most have 50kWh or more. So most EVs will include more than £10,000 ($12,500) just in batteries alone, which goes a long way to explaining why they are so much more expensive. Bloomberg New Energy Finance corroborates these calculations, putting batteries at 30 per cent of an EV’s cost in 2020. In comparison, an ICE car just has the cost of a metal box to contain its fuel.

...

A couple of months ago, it was revealed that Tesla was working with CATL on lithium iron phosphate (LFP) batteries, and these could be the real gamechanger. LFP batteries don’t use cobalt and have a roadmap to push well past the magical $100 per kWh (wholesale) that is considered the threshold for EVs being cheaper than ICE vehicles. Batteries once cost over $1,000 per kWh in 2010, then $381 in 2015, and are now at around $147 per kWh, according to James Frith, head of energy storage at Bloomberg New Energy Finance. Frith estimates that LFP batteries will hit $100 per kWh by 2023 or 2024, and just $61 by 2030.

https://www.forbes.com/sites/jamesmorris/2020/07/11/teslas-shift-to-cobalt-free-batteries-is-its-most-important-move-yet/#5101bca446b4

Let's hope it becomes the norm and that this ridiculous Ah habit dies out !

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The hour is a luddite unit....like the inch, foot, yard, rod shit....should be Watt-seconds. SI...

Would benefit the lithium marketing effort. That 17,280 W-h becomes 62 Megawatt-seconds. Which I guess some would foolishly shorten to 62 Megawatts.

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1 hour ago, yl75 said:

A couple of months ago, it was revealed that Tesla was working with CATL on lithium iron phosphate (LFP) batteries, and these could be the real gamechanger. LFP batteries don’t use cobalt and have a roadmap to push well past the magical $100 per kWh (wholesale) that is considered the threshold for EVs being cheaper than ICE vehicles.

I might be wrong here but I thought 1st Generation prototypes they mucked around with LFP then bailed and went NCA chemistry, or Nickel-Cobalt-Aluminium Oxide.

So maybe a full circle in the energy density race???? Sailboaters had it right all along. :lol: Trouble is might drive the price of LFP up again :angry:

I think most of the auto industry appears to use NMC or Nickel-Manganese-Cobalt.

Nickel is maybe one third to half the price of cobalt.

Everything You Ever Wanted To Know About Tesla Batteries

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36 minutes ago, jack_sparrow said:

I might be wrong here but I thought 1st Generation prototypes they mucked around with LFP then bailed and went NCA chemistry, or Nickel-Cobalt-Aluminium Oxide.

So maybe a full circle????

I think most of the auto industry appears to use NMC or Nickel-Manganese-Cobalt as nickel maybe one third to half the price of cobalt.

Everything You Ever Wanted To Know About Tesla Batteries

Indeed, but that is good news regarding getting "cheap" LFP with high energy density for sailboats, CATL is also due to build a big LFP batteries plant in Germany apparently :

https://www.futurecar.com/4024/Honda--Motor-Co-Invests-in-Battery-Maker-CATL-Will-Jointly-Develop-EV-Batteries

(that article doesn't say LFP but I think it is), or :

https://www.prnewswire.com/in/news-releases/catl-s-ess-solutions-and-lfp-technology-take-centre-stage-at-ees-europe-2019-867464822.html

Also interesting is that this "LFP revival" is also linked to the Chinese law evolution regarding EV subsidies apparently :

Quote

LFP battery to be the favorite again
Certain battery manufacturers and EV makers have been considering whether to focus on the production and utilization of the lithium-iron phosphate (LFP) battery for EVs because the value of subsidies has been cut so significantly, market participants told Fastmarkets. This is because it is harder to cover the higher production costs for NCM lithium-ion batteries with the lower subsidies.
The cost to produce LFP battery materials is about 10,000 yuan per tonne lower than that for NCM523 battery materials, let alone the more expensive NCM622 and NCM811 battery materials, a second battery materials producer said.
“We expect the consumption of LFP battery materials to increase this year in the lithium-ion batteries sector due to the lower production costs,” Vicky Zhao, Fastmarkets battery materials analyst, said.
Since no cobalt is needed to produce LFP batteries, one long-term scenario is that even with the anticipated growth in EV production in China in the next few years, the market demand for cobalt may not grow at a similar rate as achieved so far.
 

https://www.metalbulletin.com/Article/3866890/FOCUS-Whats-the-impact-of-Chinas-2019-EV-subsidy-policy.html

(as the subsidies also imposed a minimum range for EV, which also pushed towards NMC or NCA)

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21 minutes ago, yl75 said:

Indeed, but that is a good news regarding getting "cheap" LFP with high energy density for sailboats, CATL is also due to build a big LFP batteries plant in Germany apparently :

LFP in our cell configuration might go the other way and rebound in price. It is hard to predict because the Chinese dominate and control the market. Also our supply in the west of 3.2v cells still largely comes from what is leftover in China where defence users get first bite. 

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8 minutes ago, jack_sparrow said:

LFP in our cell configuration might go the other way and rebound in price. It is hard to predict because the Chinese dominate and control the market. Also our supply in the west of 3.2v cells still largely comes from what is leftover in China where defence users get first bite. 

But this new mass production of LFP will perhaps change that (I am not in the market to buy any currently, but hope to be there in the coming years), what do you think about sites like below for instance :

http://www.evlithium.com/CATL-Battery.html

And what about the suitability of Aluminium enclosed modules vs the typical plastic ones of CALB or Winston for the marine environment ?

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32 minutes ago, weightless said:

Yeah, then the conversion to joules would be easy :)

...so when I am in the cockpit contemplating upon my beer I can easily figure in my head if the slab of beer I will drink today contains more or less energy than my house bank....because in progressive nations the food energy content is rightly recorded in Joules, not the antique US calorie.

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1 hour ago, yl75 said:

But this new mass production of LFP will perhaps change that (I am not in the market to buy any currently, but hope to be there in the coming years), what do you think about sites like below for instance :

http://www.evlithium.com/CATL-Battery.html

Mass production cost savings is geared towards EV not commercial/domestic 3.2v cells. Price is dictated by raw cost of lithium. It peaked in mid 2017 and dived following world overall car sales, plateued, declined then plateaued again then Coronavirus hit. It will plateau now and very steadily climb. 

Evlithium are a reseller, China online beware. Ex Hong Kong bit more reliable.

CATL one of many Chinese battery factories.

I only recommend and use CALB (China Aviation Lithium Battery) as their QA is good, specs are real if not conservative, readily available worldwide for replacement/additions and each cell serial numbered and marketed from same batch so cell voltages match pretty well. (See my balancing post). Have a publically listed parent and been around over 10 years. The Govt still has a piece of them too I think.

Winston Chung (Thunder Sky & Winston) a pioneer and Winston's are under Mastervolt cover. CALB IMO better cell.

1 hour ago, yl75 said:

And what about the suitability of Aluminium enclosed modules vs the typical plastic ones of CALB or Winston for the marine environment ?

Plastic works, cheaper, doesn't corrode and not conductive. Sailboat fractional C rate so doesn't generate high heat and case deformation not an issue if packs built with alloy compression end plates on long side. Alloy strength and heat sink cell case not needed for fractional C use. I imagine not cheap. See my CALB reasons for supply source.

Lithium price. yuan per tonne

IMG_20200731_144001.jpg

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1 hour ago, El Boracho said:

...so when I am in the cockpit contemplating upon my beer I can easily figure in my head if the slab of beer I will drink today contains more or less energy than my house bank....because in progressive nations the food energy content is rightly recorded in Joules, not the antique US calorie.

That's KILOCalorie, heathen.

But, like watt-hours, we shorten it conversationally...

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1 hour ago, jack_sparrow said:

Mass production cost savings is geared towards EV not commercial/domestic 3.2v cells. Price is dictated by raw cost of lithium. It peaked in mid 2017 and dived, plateued then Coronavirus hit. It will plateau now and very steadily climb. 

But aren't  cells like below :

2017121133435013.png

2017121133631245.png

exactly the same as the ones that will or are used for EV ? (18cm high seems like the proper height to build an EV battery pack)

Evlithium are a reseller, China online beware.

Yes, understand that, and indeed ensuring you get genuine products probably takes some care.

CATL one of many Chinese battery factories.

Indeed, but a very big one (and rising), listed n°1 in wiki fr, n°3 in wiki eng (in terms of GWh produced), ahead or right behind Panasonic and BYD, not sure which is right. And apparently they are the ones producing the most energy dense LFP cells right now (using some patented new tech or something)

I only recommend and use CALB (China Aviation Lithium Battery) as their QA is good, specs are real if not conservative, readily available worldwide for replacement/additions and each cell serial numbered and marketed from same batch so cell voltages match pretty well. (See my balancing post). Have a publically listed parent and been around over 10 years. The Govt still has a piece of them too I think.

Indeed CALB seems to be more serious in terms of production identification and serial IDs than CATL, but less energy dense when comparing the above to :

http://www.evlithium.com/CALB_Battery/122.html

(137 Wh/kg for the CATL one, 101 for the CALB)

Winston are under Mastervolt cover. CALB IMO better cell.

Plastic works, cheaper, doesn't corrode and not conductive. Sailboat fractional C rate so doesn't generate high heat and case deformation not an issue if packs built with alloy compression end plates on long side. Alloy strength and heat sink cell case not needed for fractional C use. I imagine not cheap. See my CALB reasons.

Would prefer plastic as well, but looks like CATL are all aluminium enclosure. And regarding the plastic enclosures, are the Winston style ones made to allow some air flow between the cells for cooling ? (compared to the more flat CALB enclosure).

Lithium price. yuan per tonne

IMG_20200731_144001.jpg

PS : intertwined red, as I'm not sure how to break quotes easily...

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5 hours ago, jack_sparrow said:

Pretty amazing when you think we have more computing power in our cell phones than what those guys had...plus we don't have a shred of bakelite. :lol:

Actually our sailboats probably have more computing power than Houston had.

Mine has 2 of the latest generation Raspberry Pi 4's with 4Gb of RAM on board, and I'm planning on adding a third one, just because I can.

The whole argument WRT cell replacement is a crock though, because the default assumption is, the LFP batteries are individual cells and the LA batteries are fixed assemblages of 6 cells. You can buy single 2V LA cells after all, and the 'drop-in' LFP packs are likely not really able to be disassembled.

So all of you should just drop it as it's crap.

Says he who once had a big bank of nickel-iron batteries in a research setup, big array of individual cells in a series-parallel config....

FKT

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1 hour ago, yl75 said:
hour ago, jack_sparrow said:

Mass production cost savings is geared towards EV not commercial/domestic 3.2v cells. Price is dictated by raw cost of lithium. It peaked in mid 2017 and dived, plateued then Coronavirus hit. It will plateau now and very steadily climb. 

But aren't  cells like below :

  2017121133435013.png

  2017121133631245.png

exactly the same as the ones that will or are used for EV ? (18cm high seems like the proper height to build an EV battery pack)

"Mass production cost savings is geared towards EV not commercial/domestic 3.2v cells."

So you reakon 3.2v cells are exactly the same as mass produced EV.

Do I really have to keep reading??

images - 2020-07-31T171624.437.jpeg

images - 2020-07-31T171651.381.jpeg

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Btw, on CATL website, I find below map quite "amusing" :

capture-de28099ecc81cran-2020-07-31-acc8

 

https://www.catlbattery.com/en/web/index.php/about/information

 

With the dotted blue line all around the South China sea (and even more) including the Paracel islands (disputed with Vietnam), and the Spartly Islands (disputed amongst China, Vietnam, Indonesia, Brunei, the Philippines, Malaysia, and Taiwan ! ) :

https://en.wikipedia.org/wiki/Spratly_Islands

 

They might not be State owned, but they for sure have some "connections" ;)

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12 minutes ago, jack_sparrow said:

Do I really have to keep reading,??

 

images - 2020-07-31T171624.437.jpeg

images - 2020-07-31T171651.381.jpeg

Ok, but these cylindric cells are the typical NMC or NCA chemistry ones, my understanding is that for LFP, prismatic type cells will also be used in EV (maybe more Buses than cars, but they will be the ones used) :

 

https://cleantechnica.com/2020/02/19/catl-built-tesla-model-3-battery-pack-will-use-prismatic-cells/

With-prismatic-batteries-scaled.jpg

 

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4 hours ago, El Boracho said:

The hour is a luddite unit....like the inch, foot, yard, rod shit....should be Watt-seconds. SI...

Would benefit the lithium marketing effort. That 17,280 W-h becomes 62 Megawatt-seconds. Which I guess some would foolishly shorten to 62 Megawatts.

Victrons "drop in" they call the "SuperPack" all in one blahh blah series they do in LA battery case sizing and incorporate Wh on the case. They don't do this for their "external" BMS offerings. Different colours also to differentiate. Parallel only no series use. (Available 12.8/25.6 nominal)

I have never broken into one of these but I suspect they use a Chinese manufacturer but as branded as Victron unlike their first generation lithium offerings. 

Lithium-SuperPack-12.8V-100Ah-1280Wh-front-angle_93210805.png

IMG_20200731_173826.jpg

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22 minutes ago, yl75 said:

Case closed 

And where does it say they will be replicating existing 3.2v cases? Maybe the words "cells tailor made" escaped you?

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13 minutes ago, jack_sparrow said:

And where does it say they will be replicating existing 3.2v cases? Maybe the words "tailor made" escaped you?

Come on ...

The case is closed now, of course Tesla needs some level of tailor made, then What ?

 

With-prismatic-batteries-scaled.jpg

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1 hour ago, yl75 said:

Come on ...

The case is closed now, of course Tesla needs some level of tailor made, then What ?

As you paid your $8 for your argument. 

- Firstly you tell me how what you have shown there doesn't collide with what I said, noting EV cells are up to 50% smaller in one or more dimensions than commercial 3.2v cells for a reason.  

Then assuming you don't mind more cells, more cost and complexity mixing up the application and constraints it introduces like more real estate needed for batteries, which are shallower. Say 180mm versus 280mm deeper and wider. You cell is a EV cell. 

- Secondly how and where do you purchase a Tesla "tailor made" cell for non Tesla use?

- Thirdly where do you get the ancillaries such as cell boards and cell plates from to build a pack from for these Tesla "tailor made" cells?

I will let you keep the leftover argument closed change.

4 hours ago, jack_sparrow said:

LFP in our cell configuration might go the other way and rebound in price. It is hard to predict because the Chinese dominate and control the market. Also our supply in the west of 3.2v cells still largely comes from what is leftover in China where defence users get first bite. 

4 hours ago, yl75 said:

But this new mass production of LFP will perhaps change that

 

3 hours ago, jack_sparrow said:

Mass production cost savings is geared towards EV not commercial/domestic 3.2v cells. Price is dictated by raw cost of lithium.

 

2 hours ago, yl75 said:

But aren't  cells like below :

 2017121133435013.png

2017121133631245.png

exactly the same as the ones that will or are used for EV ? (18cm high seems like the proper height to build an EV battery pack)

 

 

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1 hour ago, jack_sparrow said:

As you paid your $8 for your argument. 

- Firstly you tell me how what you have shown there doesn't collide with what I said, noting EV cells are up to 50% smaller in one or more dimensions than commercial 3.2v cells for a reason.  

Then assuming you don't mind more cells, more cost and complexity mixing up the application and constraints it introduces like more real estate needed for batteries, which are shallower. Say 180mm versus 280mm deeper and wider. You cell is a EV cell. 

- Secondly how and where do you purchase a Tesla "tailor made" cell for non Tesla use?

- Thirdly where do you get the ancillaries such as cell boards and cell plates from to build a pack from for these Tesla "tailor made" cells?

I will let you keep the leftover argument closed change.

 

 

I have clearly shown that :

1) Prismatic LFP cells target the EV market (and there are not only cars in this market, but also buses, trucks, forklift, whatever) (and yes, there are also cylindrical LFP cells, but here we see that prismatic will/are already used for EV

2) I bet that : you will get prismatic LFP cells bigger than the one taken as example, also targeted to EV, like buses or whatever

3) Tesla is not the only EV company in the world, you will be able to buy these prismatic LFP cells, just like you buy CALB today

4) why would you need these ancilliaries if you build a DIY LFP bank ? Do you need Boeing or Airbus or whatever ancillaires when you buy CALB cells today ?

5) moreover these cells will be very appropriate if you target also electric propulsion on a sailboat

 

Again, the case is clearly closed : You lost ! :)

(a bit of a pity for an LFP Über expert I must say <_< , but w'll try to keep it quite for this time, and not even counting the fact that an LFP expert such as yourself were not aware of Tesla moving to prismatic LFP with CATL for China, when the news was all over the place .. )

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1 hour ago, jack_sparrow said:

As you paid your $8 for your argument. 

- Firstly you tell me how what you have shown there doesn't collide with what I said,...

32 minutes ago, yl75 said:

I have clearly shown that :

1) Prismatic LFP cells target the EV market...

 

Complete dribble.

This was your only objective anyway...and you think I don't know. Your kind have been obvious online for the last decade with LFP. That's why I only addressed your first bit of dribble about LFP economy. 

It is why no one with LFP experience shares much any more their experience online, just because of dickheads like you. Some even don't even consult anymore in real life to avoid fucktards like you.

My last time here was years ago. You remind why that a good decision.

Will keep my eye peeled when you make your first LFP purchase and it's going to shit. 

A meal best served cold. Turnip.

32 minutes ago, yl75 said:

(a bit of a pity for an LFP Über expert I must say <_< , but w'll try to keep it quite for this time )

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1 hour ago, yl75 said:

2) I bet that : you will get prismatic LFP cells bigger than the one taken as example, also targeted to EV, like buses or whatever

A bookmark of your bet already lost.

"I bet that : you will get prismatic LFP cells bigger than the one taken as example,.."

Commercial LFP 3.2v cells are mostly all prismatics and their "energy density" or energy to physical size has not changed markedly in 20 years. That is why they are bigger than EV standard size in LFP, the one you cited.

You have also already lost the bet on LFP physical cell size too.

Turnip.

keith-10000.jpg

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On 7/24/2020 at 5:26 PM, fufkin said:

Not sure if this applies but...

... my 1-both-2 battery switch is set-up as: 1 powers two Lifeline house which are also predominantly(pretty much always) used to start the engine. For regular use the switch stays on 1, that way the draw down, accounting for starting, is equal on both batteries(as opposed to using a 1 start, 2 house setup). 2 powers a separate(never used really) emergency start battery(ultima red top), and Both powers the two house and the emergency start all at once(on a rare cold day this has been used to boost cold crank amp capacity). So basically 1 is powering house and start needs 99.9% of the time.

This system has worked great and much better than the way I recall 1 Both 2 setups (1 house 1 start) working for my boat many years ago. 

Is there any reason why this simple 1 Both 2 setup couldn't work for a 3 battery lithium bank on 1 and an emergency start on 2?

 

How do you charge these banks with different chemistry?

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1 hour ago, jack_sparrow said:

A bookmark of your bet already lost.

"I bet that : you will get prismatic LFP cells bigger than the one taken as example,.."

Commercial LFP 3.2v cells are mostly all prismatics and their "energy density" or energy to physical size has not changed markedly in 20 years. That is why they are bigger than EV standard size in LFP, the one you cited.

You have also already lost the bet on LFP physical cell size too.

Turnip.

keith-10000.jpg

Whatever ...

6a00d8341c4fbe53ef025d9b4ac74a200c-800wi

Note : And LFP energy density is indeed changing

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5 hours ago, Fah Kiew Tu said:

Mine has 2 of the latest generation Raspberry Pi 4's with 4Gb of RAM on board, and I'm planning on adding a third one, just because I can.

The whole argument WRT cell replacement is a crock though, because the default assumption is, the LFP batteries are individual cells and the LA batteries are fixed assemblages of 6 cells. You can buy single 2V LA cells after all, and the 'drop-in' LFP packs are likely not really able to be disassembled.

So all of you should just drop it as it's crap.

Says he who once had a big bank of nickel-iron batteries in a research setup, big array of individual cells in a series-parallel config....

FKT

You could make a bank up out of those bigass Rolls-Surrette LA cells...

It's more about the "repairablility" of LFP away from resources, which I would rate has higher than sealed or wet LA batteries which go completely tits-up.

But that's just like, my opinion, man.

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1 hour ago, yl75 said:

Note : And LFP energy density is indeed changing

Horseshit.

You can't change the energy density of cathode materials. You can certainly play with construction techniques and play with the few anode materials available etc, but that applies to all chemistries.

The latter also comes with risk factors and not a simple case of say going from graphite to higher density silicon or lithium anodes. Peppering silicon in with graphite is now being used. 

More to the point LFP cathode energy density of around 530 watt-hours per kilogram is regarded by industry as around the safe maximum for sailboat applications. By comparison the cathode Nickel-Cobalt-Aluminium Oxide in a Tesla is around 680.

The EV door is down the corridor.

Turnip.

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Perfect LFP cell size (and part of the EV target market line) :

catl-lfp302-ah-battery-stands-on-display

But Maybe too big for Jack_s, although let's hope he admits that if too small and too big both exist, then nothing forbids  "right size" to also exist...

 

As to LFP energy density :

Quote

As you can see LFP seems almost perfect for every application, but with poor energy density isn’t suitable for electric cars.

Fortunately, for a while now the Chinese government determines the amount of subsidies for electric vehicles depending on range and battery pack energy density. Requirements for electric passenger cars are more demanding than for electric buses.

This made most battery cell makers completely replace LFP with NCM cathodes in batteries for electric passenger cars, however a few decided to improve LFP. That was the case of BYD, which introduced manganese to the cathode and managed to increase the energy density to 165 Wh/kg. However, this figure still isn’t enough to get the maximum subsidy, more improvements need to be made.

 

Lithium Ferro Manganese Phosphate (LFMP)

  • Energy density: (★★★) 3/5
  • Power density: (★★★★) 4/5
  • Cycle life: (★★★★) 4/5
  • Safety: (★★★★★) 5/5
  • Cost: (★★★★★) 5/5

 

ETC is another Chinese battery cell maker that is successfully improving the energy density of this battery technology.

BYD and ETC share the same goal of reaching 200 Wh/kg in batteries with a LFMP cathode and a silicon/carbon anode, when this happens we’ll finally get cobalt free batteries with decent energy density, that are extremely safe, durable and cheap.

 

Quote

Lithium Ferro Phosphate (LFP)

LFP was one of the earliest Li-ion technologies commercialized, primarily due to its durability and safety. However, it has been gradually phased out of EV batteries because of low energy density and replaced with more powerful NMC.

Recently a new form of LFP has been developed that incorporates manganese (LFMP), significantly raising the energy density. This new cathode along with a silicon-carbon anode demonstrates approximately 200Wh/kg, at the cell level. This is much higher than the past but it still does not compete with NMC811/NCA at 300Wh/kg at the cell level.

Compared to high nickel NMC/NCA, LFMP is  estimated to be 20% - 25% cheaper than NMC/NCA but  30% lower energy density is still a significant barrier in EVs.

It is expected that LFMP will dominate in areas where long life and durability is essential. These markets include commercial vehicles, buses and ferries.    

 

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12 hours ago, yl75 said:

But Maybe too big for Jack_s, although let's hope he admits that if too small and too big both exist, then nothing forbids  "right size" to also exist...

OK you want to insult and look like a fuckwit your choice. Anyway others may learn something. 

"then nothing forbids right size to exist"

So to build your Tesla/LFP pack DIY if you can buy them.

- Who makes your BMS and cell boards etc for your non standard sized Tesla batteries?

- Do you know how many manufacturers there are today making "ancillaries" for standard 3.2v cells suitable for sailboat use? The smallest LFP market in the world? Seems not. 

- You know the "ancillaries" they use on CALB and Winstons etc standard 3.2v cells with standard terminal construction and dimensions?  Seems not.

- You do know cell boards/BMS, cell plates etc etc are called "ancillaries"?? Seems not.

- Your reply asking why do you need "ancillaries" for DIY indicates you haven't a fucking clue.

17 hours ago, jack_sparrow said:

- Thirdly where do you get the ancillaries such as cell boards and cell plates.....

16 hours ago, yl75 said:

4) why would you need these ancilliaries if you build a DIY LFP bank ? Do you need Boeing or Airbus or whatever ancillaires when you buy CALB cells today ?

 

Then we have a "goal post" move but not a good one, in fact one made by a drunken fool. You say LFP energy density will miraculously increase

12 hours ago, yl75 said:

As to LFP energy density:...Lithium Ferro Manganese  Phosphate (LFMP)

15 hours ago, jack_sparrow said:

Commercial LFP 3.2v cells are mostly all prismatics and their "energy density" or energy to physical size has not changed markedly in 20 years. That is why they are bigger than EV standard size in LFP, the one you cited.

 

Lithium Ferro Manganese Phosphate (LFMP) is NOT LFP. 

In fact LFMP is probably closer to Lithium Nickel Cobalt Manganese 111 (NCM 111) but without the cobolt for construction/chemistry and gravimetric energy density.

LFMP is treated as a DIFFERENT cathode chemistry entirely by the industry. For instance Lithium Nickel Cobalt Manganese in each of its variants is treated as a different cathode. On your EV article you copied from I guarantee they listed out NMC 111, NMC 811 etc as seperate cathode chemistries. You didn't notice that. How strange.

That article I guarantee also shows this 6 cathode list of energies for lithium chemistry commercially available today.

IMG_20200801_084957.jpg.cb98ca7f3a7f0ce3f538bf6e073c3be8.jpg

Remember when I said cathode energy was fixed and also said for anode a silicon and carbon mix was being used to increase energy of a finished battery. Probably not as you are not a great reader.

12 hours ago, jack_sparrow said:

You can't change the energy density of cathode materials. You can certainly play with construction techniques and play with the few anode materials available etc, but that applies to all chemistries.

The latter also comes with risk factor.....Peppering silicon in with graphite is now being used

Go look at your article. Do they talk about a silicon sprinkled carbon anode? Because of risk as mentioned even higher energy NMC/NCA makers only just game to try this anode change.

It is the anode where a proportion of the energy density increase is coming from for LFMP, not just from the different cathode chemistry. If in that article a nice snip you did there.

IMG_20200801_104920.jpg.f386940628f944bdf981f60f427c8da3.jpg

LFMP discussion has been going for years, awaiting someone to produce which is close, but no one to date. Was even discussed here on a SA lithium thread some years back and only game changer on horizon for sailboat energy. 

This because the additional energy density increases of up to 20% is still in a safe chemistry. It doesn't appear to come at the expense of longevity/cycles as those with other elements suffer from. Whether they become available in other than passenger/automotive format, only time will tell. 

You clearly don't understand production passenger/vehicle formats are vastly different to other commerical applications.

This may help.

____________________________________

Finally what your entire argument is based on is in the future there will be no difference between passenger automotive  style and commercial LFP batteries as there is today in size and cell construction. Complete fucking nonsense.

The big pictures you keep flashing up are not passenger/automotive LFP cells coming out of these new factories. They are LFP for trucks, buses and commercial use etc. LFP prismatics, they have been around for years. The standard 3.2v commercial varient is the same thing.

The small one is passenger/automotive LFP still prismatic, square bulky case and why it is only 180mm deep, a automotive design constraint. It is not found in any large scale passenger vehicle production because of that volumetric density issue.

Like all passenger vehicles it obviously relys on its "area" NOT "depth" to maximise "volumetric" energy density for BOTH chemistry and cell construction. Hardly suitable for all but passenger vehicle use.

Go Google what "volumetric" energy density is as opposed to what "gravimetric" energy density means in EV speak if you don't understand that.

While you are at it Google CATL patents as it seems you have a hard on for them.  You don't work for them do you?? 

What you will find is CATL hold the patent to removing modules from EV auto style battery packs and making one large sucker. That probably explains the strange CATL Tesla tie up as both battery makers.

No idea of the detail but I suspect with lower energy density they can cram more cell pouches in by having no replaceable modules and maybe without needing cylindrical alloy cases anymore for structural and cooling safety. That packaging difference lowers cost and increases volumetric energy density.

So that is how they increase "volumetric" energy density and therefore mileage over normal LFP modules, but where the "gravimetric" density of the LFP chemistry is unchanged. If they change from LFP to LFMP then around a 20% energy density boost incl from changing the anode.

That LFP or LFMP large scale production passenger vehicle battery will never ever see a boat, never fucking ever.

Anyway that might interest somebody. 

Yl75 you really are not very good at this.

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