Understanding Lead-Acid Battery Life

[john61ct]

I personally would never bother running ICE power just to charge a lead bank once it gets past 85-90% and amps have started to trail down to a tiny rate relative to the full potential output.

Replacing more frequently, or

going to another chemistry, or

finishing the long tail with

a bit of solar, or

buying a small LFP banks to try the hybrid idea

all make a lot more sense to me.

Now if other useful work like propulsion, making water or charging holding plates would be going on anyway, that's a different story

[a64pilot]

Why would you not finish charge with ICE?
You have to remember a few things, first fuel and actually life of the generator isn’t really the issue here, and it’s not a 12 months, 365 days a year use he has.
He works and sails when he can, I’m sure he has a much more liberal work schedule than most, but his use is not the mom and pop sitting at anchor most of the time cruising like most of us do.
I take it his use is to as often as possibly assemble a professional level crew and sail hard to some exotics destination, return and wait to do something similar again.
Not as I say spending a month or two on a ball in Marathon etc.

Completely different usage than average “cruising” we can’t or shouldn’t extrapolate what works for the average cruiser to him.


At least this is what I think his usage is.

[tanglewood]

Originally Posted by ArmyDaveNY

Do you think the desulfication chargers will help solve the shortened life of the batteries? I've read some good reviews on some of them, in particular the ones from PulseTech.

I had a PulseTech on my Trojan L16 bank. I think it’s impossible to say whether it had any effect at all one way or another, so plenty of room to believe whatever you want, and die defending it.

[Dockhead]

Originally Posted by a64pilot

Why would you not finish charge with ICE?
You have to remember a few things, first fuel and actually life of the generator isn’t really the issue here, and it’s not a 12 months, 365 days a year use he has.
He works and sails when he can, I’m sure he has a much more liberal work schedule than most, but his use is not the mom and pop sitting at anchor most of the time cruising like most of us do.
I take it his use is to as often as possibly assemble a professional level crew and sail hard to some exotics destination, return and wait to do something similar again.
Not as I say spending a month or two on a ball in Marathon etc.

Completely different usage than average “cruising” we can’t or shouldn’t extrapolate what works for the average cruiser to him.


At least this is what I think his usage is.

You got my use case, but running the generator to do finish charges is really a PITA. It's a few hours a day of running the generator more than what would ordinarily be required. I would spend a few thousand just to solve that, let alone the other problems.



Also, running the generator is not all that economical. If we figure it has a useful life of say 6,000 hours, and it cost about £20,000, then every hour of running it is costing me £3.33 just in amortization, plus fuel.



As you say it's not the decisive issue in the context of all the other expenses, but it adds weight to the feasibility of spending some money to avoid it.


But lead batteries which can live 1000 cycles with hard PSOC usage would be a perfectly acceptable solution. Fireflies for sure would do it, but they are not available here and apparently much more expensive than lithium. If those Trojan L16's could fit anywhere, and if they come anywhere near to the testing data (which I believe was independent, not Trojan's) for cycle life in PSOC cycling, then that would be another acceptable solution, and already at a much more attractive price.

[kmacdonald]

Dockhead, I think the Trojan Solar Industrials might be a good fit for you. Solar Industrial Line Flooded | Trojan Battery Company
Your boat is big enough to tolerate the weight. Finding room might be an issue. They are arguably reasonably priced. As for reliability, they are as bulletproof as you can get. No exotic charge system necessary.

LFP won't work in the cold climates you cruise.

[john61ct]

Yep, those are my reasons, noise, fuel, wear & tear costs are high, compared to say a couple 80W folding solar blankets put out 3-4 days a week.

[john61ct]

I think a 100AH or smaller LFP pack, even a drop-in from BB,

just managed manually, charged in the living space,

can be used for testing the long-tail hybrid idea, also

starter usage or emergency backup or maybe the windlass / bowthruster?

_____
At $500 for 100AH, FF are much cheaper than any quality LFP available here in the US.

Not counting experiments like Newhaul's.

But as we've seen, pricing differentials vary widely by continent.

[john61ct]

If not drop-in, a 4- or even 8- pack of CALBs fits in a Pelican case.

[tanglewood]

Originally Posted by john61ct

I think a 100AH or smaller LFP pack, even a drop-in from BB,

just managed manually, charged in the living space,

can be used for testing the long-tail hybrid idea, also

starter usage or emergency backup or maybe the windlass / bowthruster?

_____
At $500 for 100AH, FF are much cheaper than any quality LFP available here in the US.

Not counting experiments like Newhaul's.

But as we've seen, pricing differentials vary widely by continent.

I paid a little under $1000 for 180ah @12v CALB cells. So that’s within spitting distance of Firefly at $500 for 100ah @12v

[Kenomac]

Originally Posted by a64pilot

I don’t think he could fit enough of them.
I think his answer is one of five things.
1. Continue as is with frequent replacements
2. Fit a much smaller genset and run it for 8 hours or more a day, cause even if you discharge to 50% and autostart the genset, the bank will be 100% fully charged in eight hours, as long as you have enough bank to carry you through the next 16 hours and not go below 50% SOC this works. Likely can do it with less than eight hours, but I’m sure eight would cover it.
3. Fit Firefly batteries and reduce your gen run time maybe by half
4. Fit LFP and maybe reduce gen run time by half or a little more?
5. Fuel cells, but I don’t know of any big enough and fuel may be an issue?
Eight hours of gen run time on an aggressively sailed boat ought not be too obnoxious, you could also do all of your cooking and watermaking during that time, I assume no clothes washing.
So you need a bank large enough to carry your electronics, bilge pump etc for 16 hours. Shouldn’t have to be a huge bank for that?

If your really worried about heeling, pendulum mount the thing like a stove.

On edit of course you don’t need a smaller genset, just likely just charging batteries is not really loading down what you have.

Deck mounted solar.

[john61ct]

Originally Posted by tanglewood

I paid a little under $1000 for 180ah @12v CALB cells.

Actually cheaper, given the usable AH difference.

Link?

[kmacdonald]

Originally Posted by tanglewood

I paid a little under $1000 for 180ah @12v CALB cells. So that’s within spitting distance of Firefly at $500 for 100ah @12v

Yep, and LFP wins that battle EASILY IMHO.

[mbartosch]

Originally Posted by john61ct

If not drop-in, a 4- or even 8- pack of CALBs fits in a Pelican case.

If anyone needs an idea how that could be done - this is the LiFePO4 battery pack we use for our electric dinghy motor:

https://www.entropypool.de/2015/06/0...-battery-pack/

Over the time I have built two of these packs and upgraded the wiring so they can each sustain 50 A of charge/discharge (70 A burst).

These packs are an extremely convenient way to carry around a powerful energy source, and they can even be used to extend our house bank during longer sailing passages.

They can even run the entire boat electrics in case of a failure; the following article describes this use case when the old Lead Acid bank on our boat failed during our first shakedown cruise: https://www.entropypool.de/2015/06/2...-bank-failure/

The only downside of the distinct DIY look: you better don't carry them around in public in these times...

[tanglewood]

Google.com. CALB CA180 price. Market price is $250 each, give or take.

[Dockhead]

Originally Posted by kmacdonald

Dockhead, I think the Trojan Solar Industrials might be a good fit for you. Solar Industrial Line Flooded | Trojan Battery Company
Your boat is big enough to tolerate the weight. Finding room might be an issue. They are arguably reasonably priced. As for reliability, they are as bulletproof as you can get. No exotic charge system necessary.

LFP won't work in the cold climates you cruise.

LFP, at least the Winston ones, work fine in Arctic conditions. It seems to me that a majority of the expedition boats I met are using them. Any LiFePo can be charged down to 0C, and the boat can't get colder than that unless you are overwintering and frozen into the ice. The Winston cells are supposed to be good down to -20C.




The Trojan L16 batteries, various ones of them, do look like they would work really well for me. As I posted, I would be delighted with 1000 real life cycles, especially at the reasonable prices of those batteries.


But alas there really isn't any place in my boat. I'll have another look in the bilges when I'm back on board, but I don't think there's much hope.