olsurfer

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Asking those of you who are familiar with lithium ion batteries, in relation to your daily amp needs, what percentage of amp capacity, over those needs, do you have in your battery packs and how far do you draw them down? I'm coming up to speed on lithium ion batts but would like to hear some opinions from experience.

Also interested in which brands gave you product satisfaction with flexible solar panels, multi stage charge controllers, lithium batteries and monitoring systems.

My usage is for a 12 volt frig, minimal interior lighting, nav lights, nav gear, auto pilot and stereo.

Thanks!

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Aloha,

I have only had lithium-ion batteries on one boat - a Moore 24 - that i raced solo to Hawaii. They worked well as you could discharge them very deep and they were much lighter than traditional lead/acid batteries. Weight savings was my main motivatino in buying them.

As for flexible panels, i have now had Solbian brand flexible solar panels on that boat and two others, including my current boat where i have two 68w Solbian panels. They are not the cheapest, but there's a reason most high end boats with flexi panels run them! They rock! I can make .1-.2 amps AT NIGHT off a full moon! I always get my Solbians from bruce schwab (bruceschwab.com) and he gets me dialed in with Genasun MPPT technology multi stage controllers. 

as far as percentages, its hard to say, depends how you're using the boat, but something that can power the boat at least through the night with all systems running. Depends a lot on your intended usage. running solar only and with small panels and batteries on a solo race to Hawaii on a cloudy year.... ugh. Just something to consider,, even the best panels don't work too well when it's cloudy.

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If I could get my grubby mits on them I'd buy Carbon Foam. Seems to be the best of the lead acid and lithium in one.

 

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8 hours ago, ronnie_simpson said:

Aloha,

I have only had lithium-ion batteries on one boat - a Moore 24 - that i raced solo to Hawaii. They worked well as you could discharge them very deep and they were much lighter than traditional lead/acid batteries. Weight savings was my main motivatino in buying them.

As for flexible panels, i have now had Solbian brand flexible solar panels on that boat and two others, including my current boat where i have two 68w Solbian panels. They are not the cheapest, but there's a reason most high end boats with flexi panels run them! They rock! I can make .1-.2 amps AT NIGHT off a full moon! I always get my Solbians from bruce schwab (bruceschwab.com) and he gets me dialed in with Genasun MPPT technology multi stage controllers. 

as far as percentages, its hard to say, depends how you're using the boat, but something that can power the boat at least through the night with all systems running. Depends a lot on your intended usage. running solar only and with small panels and batteries on a solo race to Hawaii on a cloudy year.... ugh. Just something to consider,, even the best panels don't work too well when it's cloudy.

I and a friend have Solbian panels but we haven't had them for long.  How would you rate them in terms of longevity or durability?

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7 hours ago, N1772 said:

If I could get my grubby mits on them I'd buy Carbon Foam. Seems to be the best of the lead acid and lithium in one.

 

My plan is to acquire some Firefly batteries when the current bank of lead acid needs to be replaced.  Hopefully at that time they have better availability, although I'm not sure if that's still an issue.  The stats and real world test results are very impressive.

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If solar is your principal charge source LFP is probably a waste of money unless space and weight is a critical issue.

The advantages of LFP is capacity and charge acceptance rate. Your better off with a LA chemistry that is tolerant to low SOC such as the carbon varieties.

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6 minutes ago, jack_sparrow said:

If solar is your principal charge source LFP is probably a waste of money unless space and weight is a critical issue.

The advantages of LFP is capacity and charge acceptance rate. Your better off with a LA chemistry that is tolerant to low SOC such as the carbon varieties.

I'm a carbon variety. I can relate.

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On April 6, 2018 at 3:10 AM, Ajax said:

I and a friend have Solbian panels but we haven't had them for long.  How would you rate them in terms of longevity or durability?

I can not really state how long they last. On my last two boats with Solbians, I installed them, used them hard for a year and then sold that boat. 

On this boat, I just got the Solbians a month ago when I also installed my wind generator.

Solar + wind = good combo for ocean sailing

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Three of us all installed Solbian panels about 5 years ago.  Each boat has 2 panels, so as of last fall when we put the boats away, all 6 panels are working as when we installed them.  Expensive, but seem to be worth it.  

In terms of a solar system, you really need to be aware of the 24 hour draw you anticipate.  Then assume you have 8 hours of sun (or change as you feel comfortable) and figure out how many watts of solar needed to satisfy that demand in the number of hours of sun.  Then add a safety factor for cloudy/rainy days.

Your battery choice will not impact this math.  It will dictate how many amp-hrs of capacity you require.  Lead acid will need at least double your 24 hour draw if you want to be fossil fuel free, less if you have other charging sources.  We have found it easier/cheaper to really focus on reducing power draw in these equations.

 

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11 hours ago, jacrider said:

Three of us all installed Solbian panels about 5 years ago.  Each boat has 2 panels, so as of last fall when we put the boats away, all 6 panels are working as when we installed them.  Expensive, but seem to be worth it.  

In terms of a solar system, you really need to be aware of the 24 hour draw you anticipate.  Then assume you have 8 hours of sun (or change as you feel comfortable) and figure out how many watts of solar needed to satisfy that demand in the number of hours of sun.  Then add a safety factor for cloudy/rainy days.

Your battery choice will not impact this math.  It will dictate how many amp-hrs of capacity you require.  Lead acid will need at least double your 24 hour draw if you want to be fossil fuel free, less if you have other charging sources.  We have found it easier/cheaper to really focus on reducing power draw in these equations.

 

Yes, conservation is the key.

I've said several times over the past year, that my failure to account for the constant charging of personal electronic devices (phones, iPads, etc) has significantly impacted my energy budget. These things typically pull 2 amps when charging from near zero, then taper off but we're always charging something. We have a little P.E.D. solar charger meant for camping and kayaking that we'll start using. I'm also considering one of those portable charging bricks.  48 amp hours is not something to ignore.

I really need to get a digital battery monitor to accurately assess my consumption. The numbers I'm crunching just aren't working out. There's no way I could be pulling 160 amp hours in a 24 period because my house battery is never dead in only 24 hours.

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Ajax,

Don't forget, if you have LA batteries your usable capacity is about 50% of rated capacity.

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5 minutes ago, jsaronson said:

Ajax,

Don't forget, if you have LA batteries your usable capacity is about 50% of rated capacity.

Trust me, they don't let me forget.

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On 4/6/2018 at 11:07 PM, jack_sparrow said:

If solar is your principal charge source LFP is probably a waste of money (snip)

I am actively cruising with LFP charged by solar and am not finding that to be the case. 

 

The Ocean Planet/Schwab site has good info. Maine Sail’s Compass Marine site has good info. This also good:  https://www.emarineinc.com/

 

Search also here at SA for prior discussions of same: do the search via Google rather than internally

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Rock I run LFP where solar is a secondary charge source (simply to take the sting out of 24hr loads like refrigeration) and with large engine driven alts as the primary charge source that charge at full tilt irrespective of SOC (other than at the very top), that arrangement is extremely efficient in terms of power production, storage, fuel efficiency and fuel storage demands.

If I was relying solely on the limited charge rates of renewables I would be quite happy with the simplicity and lesser cost of LA chemistry as other than the difference in comparitve weight and volume for the same effective capacity, having  LFP while nice to have, doesn't make a lot of sense where low charge rates are involved.

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Jack, that’s fine if you like to crank an engine every day, but my solar is topping off my LFP, daily, while at anchor. And the high discharge tolerance of LFP means that even if it’s cloudy I still don’t have to crank an engine unless quite some time has passed.  I doubled my aH capacity in the same physical space at half the weight. And even if you don’t care about weight, space is limited.

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Charge acceptance is just one benefit of lithium. If we were talking about AGM versus FLA, I'd agree completely but as Max points out, size and weight for equivalent capacity is also beneficial. Same with number of charge/discharge cycles, low maintenance, etc. Yes, you pay up front for the cycles but in boats with poor battery access, lower maintenance and longer replacement intervals is worth a lot. The bottom line is that lithium can be justified for a lot of reasons, assuming cost isn't prohibitive.

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On 4/5/2018 at 12:24 PM, olsurfer said:

Asking those of you who are familiar with lithium ion batteries, in relation to your daily amp needs, what percentage of amp capacity, over those needs, do you have in your battery packs and how far do you draw them down? I'm coming up to speed on lithium ion batts but would like to hear some opinions from experience.

Also interested in which brands gave you product satisfaction with flexible solar panels, multi stage charge controllers, lithium batteries and monitoring systems.

My usage is for a 12 volt frig, minimal interior lighting, nav lights, nav gear, auto pilot and stereo.

Thanks!

So, you'll never charge your phone, Tablet, someone else's phone or laptop, spot-spotlight, sat phone?

What about bilge pump, you don't have one?

Are your lights LED's?

 

I've just purchased components for a stand alone system with no motor nor shore power for a race boat.

It will run 24/7 for up to four days.

I passed on lifepo4 (the preferred choice of available lithium) primarily because of the cost.

It was going to be over six times more  expensive than AGM ( Absorbed Gas Matt ).

Also relevant was the elevated fire risk, impact sensitivity ( lots of water strikes in this race ).

The attributes of lifepo4 are deep cycling is okay, number of cycles is huge, energy density is impressive, weight: about half of AGM.

Your draw you describe is going to be 5 - 10 amps depending how much you use each item listed.

Calculate your amp-hours ( ah ) per day, size your battery and panels accordingly.

Have you considered a MPPT vs PWM charger/controller?

 

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8 hours ago, Max Rockatansky said:

Jack, that’s fine if you like to crank an engine every day,

Around every 3/4 days (no solar) with large loads and most of the time when when engine on anyway motor sailing or the like. I also make water using a engine driven or electric pumps. 

I would never go back to LA in a million years but simply caution those jumping in when they don't have the usage and a lot of charge capacity to get the most out of it and weight/volume of power storage is not an issue.

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I have conventional batteries. 2 six volt for the lights, nav gear and fridges. One 12 volt to start clunky. 2GM20 Yanmar that makes 16hp. All the interior lights are LED. About 1/4 amp with them all on. Old style bulbs were 3/4 amp each. Food and beer fridges have Danfoss 35 units. Waeco beer fridge uses a few more amps. Nova Kool ?? is the other one. I have 270 watts of panels. Original 70 watt cost over $600 years ago. I will replace it some day. The 100 watt flexible panel produces an average of 2 watts because of shading from the boom, and its flat angle. remove the shading and it goes to 4 amps, aim it at the sun and it does 6 amps. I often see 9 amps from them all. Obviously a lot more if a I angled them. 12.25 is half discharged for my type of batteries. If I see that and it is a cloudy day, I fire up Clunky, who produces around 40 amps with not too many revs. 55 amps is maximum. I use a magic box that charges all the batteries separately and together. Another magic box does the same when plugged in to 120 volts. I use one of those smart regulator units for the solar panels. The numbers are too small to read, so I kept the larger amp meter. One amp meter to show the charge, another to show the discharge or use, and a volt meter. Works for us. Using all the nav gear and running lights at night, under sail, might cause a drain. I have a mast head nav light that only needs one bulb. The nav light forward on the deck also uses one bulb. We use a 1000 watt inverter to charge phones, and run the small computer.

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