AGM or Wet Cell

[Kenomac]

Originally Posted by sailorboy1

oh come on !!!!!!

NO MORE SOUP FOR YOU! Sailorboy.

[zboss]

Originally Posted by a64pilot

Li-Po batteries would fix this issue, with them maybe I would never have to burn any fuel at all to charge batteries cause they don't like to be 100% fully charged, they like being cycled between about 50% to 85%, and their charge acceptance rate is through the roof anyway.

I thought that issue kinda went away... to not fully charge. That the new thinking for lithium is that you can charge them to full but not do so with a lot of current. Also that slow charging them and keeping them cool is better for the battery overall than worrying about charging them full.

I honestly don't know but have been reading a lot of articles about "drop-in" lithium replacement batteries.

They are substantially more expensive but we would save more than 200 pounds, which is a lot of beer that we can then bring to the Bahamas! Ten cases.

[a64pilot]

I honestly don't know what the current thinking is on Lithium based batteries is, I thought it was avoid full charge so you didn't accidentally overcharge, full is fine, just don't ever overcharge as bad things can happen.
I know it's a different chemistry but most Hybrid cars only use from about 50% to 85% SOC but they rapidly cycle and I'm sure have hundreds of thousands of cycles in a banks life, maybe?

When my bank gets closer to toast, I'll look into it again, or maybe rebuild the box so I can go FLA, I don't think my next bank will be an AGM.
So far I have had excellent service, but I'm only just starting to cruise, up to now they have always sat plugged in on float, which is really the best way to care for an AGM bank. I think that is the perfect use for them, a day Sailor that always returns to shorepower

[john61ct]

LFP prefers to sit at low SoC when not being cycled.

As long as define Full as charging to 3.45Vpc (13.8V for "12V") that's fine when they are being cycled, not kept there like Lead gets floated.

High-amp charging no problem, super-high CAR

No **need** at all to ever get Full from the bank's POV, therefore best fix for chronic PSOC situations.

Next best being Firefly Oasis, which are not quite as pricey.

[foggysail]

Originally Posted by john61ct

There are a lot of factors involved, not least of which is many people keep the bank way too long.

But even with FLA, other coddling beibg equal, just getting to 100% Full nearly every cycle vs PSOC abuse will easily add many years to a quality bank's life.

Cheapest GC might only make one years' difference, so YMMV, especially if this stuff izn't fun for you.

My personal approach is even with a cheap bank, do what I can to get maximum life, so I know I "qualify" to buy an expensive bank next time around. And I enjoy the challenge.
.

A couple of things John. You are a knowledgeable guy so I question why first you assume, probably correctly, that with a cheap bank there might only be a year's performance life shortfall over those with pedigree papers. Next you go onto tell us that your goal is to maximize their life so you can qualify to buy an expensive bank the next time. I DOUBT IT.

Consider the bang one gets with a 215AH Duracell from Sams for $82-84 vs a Trojan T105 225AH selling for a bargain price of $145 around here. I think you're too smart to pay 173% more for a louder bang.

And a question for you. You mentioned somewhere above about extending the bulk/absorption time to nearer sundown to help push the SOC to nearer/into 100%. My Victron does set the maximum absorption time and I am going to guess it is adjustable. But is that not going to risk forcing the absorption voltage higher into a range where gassing might start? I agreed with your earlier recommendations that it is better to follow the specific manufacturer's stage voltage settings. Just this weekend I became conservative, followed Mainsail's recommendation and lowered my float from the the recommended setting of 13.5 to 13.4. The change is picayune but I want to minimize the potential for gassing so hopefully I never have to add water.

Now I hope your not feeling dumped on, that's not my intention here. But another point of interest pertaining to generators. Generators in morning, generators in the evening...almost sounds like a song. Now getting real.......generators, one or two mean nothing without a decent battery charger and I don't mean a Xantrex 5012 and running one's engine without a high amperage alternator such a Balmar is just a waste of pleasant tranquility.

Got to rest now, need to preserve my keyboard's life

[a64pilot]

I knew you didn't want to float a LIfe-Po bank. I don't know how you handle leaving the boat, a timer?
I assume LFP and Life-Po are both Lithium Iron Phosphate?
I'd ask more about them, but don't want to take us too far away, and there is a thread that ran way longer than I could read about them

[john61ct]

Originally Posted by foggysail

Consider the bang one gets with a 215AH Duracell from Sams for $82-84 vs a Trojan T105 225AH selling for a bargain price of $145 around here. I think you're too smart to pay 173% more for a louder bang.

Yes at that price difference may well not be worth it. But for me paying double that for Firefly, or even 5x more for LFP may well be worthwhile, IF I am confident I can coddle them properly.

Originally Posted by foggysail

You mentioned somewhere above about extending the bulk/absorption time to nearer sundown to help push the SOC to nearer/into 100%. My Victron does set the maximum absorption time and I am going to guess it is adjustable. But is that not going to risk forcing the absorption voltage higher into a range where gassing might start?
...
I want to minimize the potential for gassing so hopefully I never have to add water.

I was responding to the poster having problems, likely the sadly too common premature floatulation. Solar as a charge source is unique in that the sun sets every day, so holding Absorb too long (very very rare) is of limited risk.

None of which should have anything to do with voltage going higher than the setpoint, should never happen.

But with FLA again not much risk as long as fluid level's kept up, no harm from gassing otherwise.

Originally Posted by foggysail

generators, one or two mean nothing without a decent battery charger and I don't mean a Xantrex 5012 and running one's engine without a high amperage alternator such a Balmar is just a waste of pleasant tranquility.

Yes a good programmable high-amp shore charger is critical for many scenarios, as is an MC-614 if relying on Alt charging.

[john61ct]

Originally Posted by a64pilot

I knew you didn't want to float a LIfe-Po bank. I don't know how you handle leaving the boat, a timer?
I assume LFP and Life-Po are both Lithium Iron Phosphate?
I'd ask more about them, but don't want to take us too far away, and there is a thread that ran way longer than I could read about them

Yes LFP = LiFePO4

When not cycling the bank, leave isolated at ~10-15% SoC, or if no BM say 12V resting, and don't worry about it.

PS SmartGauge is only useful with lead chemistries.

[a64pilot]

Originally Posted by john61ct

Yes LFP = LiFePO4


PS SmartGauge is only useful with lead chemistries.

I know, but do not know how you determine SOC, voltage is almost flat right, so you can't use voltage either, so how do you do it?

[fSymo]

<gulp>

FLA's don't accept charge as well, that's an issue...

"The higher charge efficiency of AGMs allows you to recharge with less energy: Flooded cells convert 15-20% of the electrical energy into heat instead of potential power. Gel-cells lose 10-16% but AGMs as little as 4%. The higher charge efficiency of AGMs can contribute to significant savings when it comes to the use of expensive renewable energy sources (wind generators, solar panels, etc.) as your charging system can be 15% smaller (or just charge faster)."

Wondering how you y'all have your solar setups? 1000W of solar should be plenty for 300ah of discharge, no? Do you have multiple charge controllers so you don't suffer from shading on your panels? I get the whole float charge arguments, but man... fitting 1000W of solar is a LOT of panel space, and a lot of research supports the idea that you can get to 100% with AGM's, or LiFePo's (they can discharge down to 20% regularly if you can recharge them up to full regularly).

What kind of charge controllers are y'all using?

[john61ct]

Originally Posted by a64pilot

I know, but do not know how you determine SOC, voltage is almost flat right, so you can't use voltage either, so how do you do it?

AH counting monitor, Victron BMV-702 is popular.

Once you benchmark it, the resting V curve is consistent, not really flat, just need an accurate DMM.

Key for longevity is avoiding the curve's shoulders both top and bottom, knowing exact SoC is not so critical otherwise. Cut off at 12V is very conservative, run the genny for 20 or 40 minutes as you like, plenty of power for the day.

[Uncle Bob]

Originally Posted by Higgo

No Sams club ... im on Aussie soil

Supercharge Batteries. Here in Aus, no connection just a happy user.

[ranger58sb]

Originally Posted by a64pilot

Yes, an hour in the morning of generator or main engine will of course let the Solar get me fully charged, cause it adds an hour to the total charge time if done early enough.

Now come Winter I assume it's going to be longer than an hour, I should know in a few months.

My plan is two generator runs a week to get the bank to 100% and equalize once a month, with telephone conversations with Justin Goodbar, that ought to give me a decent bank life, what he said was I'll talk to you in five years.

So you are currently running the genset in the mornings, 2x/week, now? And then solar the rest of the day?

And you're not reaching 100% SOC? Is that not reaching 100% SOC on all days, or just non-genset days?

What's the impediment to running the genset more days per week? Or even daily?

-Chris

[foggysail]

Originally Posted by john61ct

Yes at that price difference may well not be worth it. But for me paying double that for Firefly, or even 5x more for LFP may well be worthwhile, IF I am confident I can coddle them properly.

We agree on many things John but not all.

Cost vs performance. Time is an uncontrolled variable so the idea of benefiting by purchasing anything where the payback period extends beyond a decade or even approaches a decade is questionable. Too many variables such as no longer having the boat, or any boat for that matter at payback. And worse, even if you are a young person, one's probability enters the equation.

[john61ct]

Advantages include more factors than just financial. Especially with LFP.

And I have spent a lot of money gaining knowledge in my life, and rarely regretted doing that as a waste of time and money.

As an IT pro, you should see my server room. . .