Best New House Battery

[Moonduster]

Titan was certainly Lithium Colbalt. I've never been able to find an instance of marine catastrophic failures of LFP.

In a cruising boat, LFPs pay for themselves based on reduced engine hours required to charge and even modest estimates of engine life and rebuild/repower cost. In fact, last time I did the math, LFP paid for themselves on the cost of diesel fuel alone in the South Pacific.

Certainly flooded batteries can be problematic in inversions, but I don't believe that's a serious reason to substitute Gel or AGM. There are lots of problems to solve for before splitting that hair unless your installation is such that the batteries are to be installed on their side.

I still can't imagine why any serious marine installation would choose anything other than 6V golf cart style flooded or LFP.

 

[estarzinger]

I've never been able to find an instance of marine catastrophic failures of LFP.

.

LFP is certainly "safer" ( but also lower energy density I believe) . . . . However . . . .

"We have a smashed safety glass window in our workshop to prove that LiFePO4 Lithium batteries can explode and catch fire if overcharged. Or more importantly over-discharged and then recharged without checking for a dead cell. We know of at least one other vendor that has had a similar experience. Also there are many examples of battery fires where no BMS was used or where an improperly designed BMS was inactive or failed." http://www.evpower.com.au/-EV-Powerpak-Custom-LFP-Batteries-.html

 

[solosailor]

I've seen the results from several LFP packs in a similar situation where it was over-discharged and an individual cell went way below 2V and was damaged resulting in a 9V instead of a 12V pack. Then the pack was charged at a full rate and the 3 remaining cells go way into over-charge. The worst I've seen when overcharging/overheating is extreme swelling and once a case melted down but never a fire luckily.

 

[DDW]

Plenty of boats, cars, RVs, planes burned down from lead acid batteries too. It's safest to stay in bed all day and don't touch anything with electrons in it.

 

[Ocean View]

"Certainly flooded batteries can be problematic in inversions, but I don't believe that's a serious reason to substitute Gel or AGM. There are lots of problems to solve for before splitting that hair unless your installation is such that the batteries are to be installed on their side."

Moonduster - Before going LFP we used flooded then AGM for decades - But the findings from the 98 hobart found that many boats could not call for help due to their wet cell batteries suffering from either salt water ingress (water inside the boat covered the batteries) or through inversion - they lost their acid - making them unable to start their engines or to use a radio call for help. - hence the change to the offshore regs only allow sealed batteries.
Agreed - Risk is low for most people, but has major impact if it occurs.

 

[Moonduster]

I should have said LFP with proper BMS ... my question still stands, any verifiable instances of LFP catastrophic failures in a proper installation that includes a BMS?

Ocean View, the findings from the 98 Hobart do more to substantiate my view of flooded batteries than to support the regulation changes. Few boats were affected in truly horrendous conditions. Lack of seamanship (the choice to continue racing) was a much larger contributing factor to the overall situation than were the presence of flooded batteries. I'm not aware of a single case in that race where the presence of flooded batteries caused the problem or the lack of flooded batteries would have changed the outcome.

 

[Spin Echo]

Another issue to consider is submersibility, another positive feature of the sealed batteries, especially with shallow bilge race boats. Its kind of nice to know if the boat takes on some water you can still have functional batteries.

 

[Moonduster]

Spin,

The typical battery is, what, 10" tall? I can understand a flat bilge boat having 3-4" of water sloshing around, but not 10".

 

[Spin Echo]

Spin,

The typical battery is, what, 10" tall? I can understand a flat bilge boat having 3-4" of water sloshing around, but not 10".

A friend of mine's speed transducer wasn't tightened properly, came loose. Lost both batteries and all electricity offshore. Not fun. I had a wave come over the companionway and my battery compartment is right next to companionway ladder. Lost one battery of the two.

I'll be getting AGM's for that reason alone in the spring. Boat is at the dock most of the time, so no need for the gourmet charging system as Maine Sail teaches.

 

[Moonduster]

So let's pretend for a moment that you had a legitimate battery box with cover and tie-down system. How was it that one stinkin' wave took out a battery? I just don't see how that's even remotely possible.

And as for the loose speedo - loosing the batteries seems to me like the very least of your problems. Sounds like they were lucky to come away with the boat - why would one be concerned about the batteries? After all, no matter the battery technology if the things get submersed, they're going to discharge and be dead in no time at all, salt water will do that to you. So Gel, AGM, LFP or flooded won't change that outcome.

Sounds to me like you're just pissing money away trying to prevent some problem that doesn't exist. Am I missing something?

 

[warbird]

Why is everybody trying to re-engineer a tried and proven system. Usa236 doesnt seem ready to upgrade the cost and complexity of the existing system. And USA236 doesnt seem to need anything more than the current system provides.

Likely a powered Windlass, AC or refrigeration are not in the plan for a J27.

 

[Moonduster]

No one is trying to re-engineer anything. He asked if there was value in replacing the battery with Gel or AGM. My belief is that there is not and in reading this thread, it seems to me that those who advocate sealed batteries are grasping at straws with respect to their "value add" for their increased cost.

Seems like an open and closed case ...

No?

 

[Spin Echo]

So let's pretend for a moment that you had a legitimate battery box with cover and tie-down system. How was it that one stinkin' wave took out a battery? I just don't see how that's even remotely possible.

And as for the loose speedo - loosing the batteries seems to me like the very least of your problems. Sounds like they were lucky to come away with the boat - why would one be concerned about the batteries? After all, no matter the battery technology if the things get submersed, they're going to discharge and be dead in no time at all, salt water will do that to you. So Gel, AGM, LFP or flooded won't change that outcome.

Sounds to me like you're just pissing money away trying to prevent some problem that doesn't exist. Am I missing something?

True, guy was lucky enough not to lose the boat, the batteries were the least of his concern, HOWEVER, a sealed battery after being submerged will at least be useful for a radio, with a wet, you got no power for any communications. As i said, my battery compartment is next to companionway ladder, the batteries are in a box, but without covers and the after getting wet one died. Also, aren't regular lead acids outlawed on offshore races nowadays anyway? It is true, for coastal sailing and around the cans, there is no better value than regular lead acids.

 

[Moonduster]

The resistance of salt water is about 0.2 ohms per meter. If we consider the two terminals of a battery to be about 1 foot apart (1/3 of a meter), then we get a resistance of 0.067 ohms. A 12V battery will generate a current of 180A through a 0.067 ohm resistor.

How long do you think your radio is going to work when your battery is discharging at that rate?

I don't care what kind of battery you have - if you immerse it in salt water it's going to be dead as a door nail before you can key the mike.

 

[Spin Echo]

The resistance of salt water is about 0.2 ohms per meter. If we consider the two terminals of a battery to be about 1 foot apart (1/3 of a meter), then we get a resistance of 0.067 ohms. A 12V battery will generate a current of 180A through a 0.067 ohm resistor.

How long do you think your radio is going to work when your battery is discharging at that rate?

I don't care what kind of battery you have - if you immerse it in salt water it's going to be dead as a door nail before you can key the mike.

Yes, thats obvious, any battery immersed for a significant amount of time in salt water is done. However, you can take an AGM out of the water and if its been submerged for not too long(im guessing less than 30 min?) , it will still work.

 

[SailMoore1]

Some people might disagree but look at the Costco deep cycle battery. I have one on my J27 and abuse it. I leave it hooked up to the smallest trickle solar panel and never charge by any other means. They are inexpensive compared to batteries at the marine store and the best part is the warranty. The first 3 years is a 100% free replacement. With the abuse I give it they last just under 3 years. This is for a J27, you have very low power requirements and will most likely abuse the battery. So the number of full cycles becomes less important than on a boat with larger power requirements.

 

[Dennisail]

Flooded or Lithium. The stuff inbetween hardly seems worth it it most cases unless there is a particular compelling reason that sealed needs to be used.

BTW my boat nearly caught on fire thanks to a faulty lead acid start battery. Eventually it developed an internal short/dead cell which dragged down the voltage of charger terminals absorbing the full 44a of charge current from my large solar array. The current turned most of the electrolyte into hydrogen gas and boiling acid, and it was too hot to touch. A spark would probably have caused a large explosion. So lets not pretend that lead acid batteries are fully safe either.

 

[Maine Sail]

Flooded or Lithium. The stuff inbetween hardly seems worth it it most cases unless there is a particular compelling reason that sealed needs to be used.

BTW my boat nearly caught on fire thanks to a faulty lead acid start battery. Eventually it developed an internal short/dead cell which dragged down the voltage of charger terminals absorbing the full 44a of charge current from my large solar array. The current turned most of the electrolyte into hydrogen gas and boiling acid, and it was too hot to touch. A spark would probably have caused a large explosion. So lets not pretend that lead acid batteries are fully safe either.

Knuckle heads will be knuckle heads no matter what the battery technolgy is they are using. I see Trojan's destroyed in less than a year, that is actually TOUGH to do, and in almost every case it is always; "Trojan's fault"......

Course you can save a lot of money by not buying into the "marine hype" like this guy did... Yep Wal*Mart chargers are just as good as a "marine" charger.... <_<

Can you say KA-BOOM!!!

 

[Dennisail]

Whoa that looks pretty bad. That could have happened to my battery. Thats one of the probs with having such a big solar array. Ideally there would have been a temp sensor on the battery, or the charger would have been "smart" enough to realise that there was too much current for too long which I know some chargers can do. But I expect this sort of thing could happen easily with enough power available. The voltage never went above 12.5V so many chargers would have happily kept going at full current as the input to slow down is by reaching a certain voltage.

A lithium bank with a BMS and individual cell monitoring would have noticed the bad cell and opened the cut off relay.

 

[Maine Sail]

Whoa that looks pretty bad. That could have happened to my battery. Thats one of the probs with having such a big solar array. Ideally there would have been a temp sensor on the battery, or the charger would have been "smart" enough to realise that there was too much current for too long which I know some chargers can do. But I expect this sort of thing could happen easily with enough power available. The voltage never went above 12.5V so many chargers would have happily kept going at full current as the input to slow down is by reaching a certain voltage.

A lithium bank with a BMS and individual cell monitoring would have noticed the bad cell and opened the cut off relay.

Yep I have long argued with the manufacturers that we need temp sensors for each battery in a bank and that they can be "daisy chained" together.. This is not difficult stuff to produce yet no one wants to truly be safe about designing battery chargers because that "costs money".... Boaters can be a cheap lot and it gets pretty easy for a charger maker to price themselves out of a market by offering features no one but a marine electrician understands the need for.......

This is also another reason I dislike using inverter/chargers for dockside charging when the vessel is unattended. Using I/C's to sit there and provide mA level current to a fully charged bank is simply stoopid :angry: , but it is "accpted" as normal.....

Some of these I/C's are capable pushing 150A into a dead short! If the single temp sensor is on the wrong battery you keep pushing current into the short until something gives. Course if I had a dime for every temp sensor I have found stuffed in a bag with the owners manual............ D'oh.......

Luckily these failures are rare, but they do happen...