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Pro's and Con's of each battery type?

Rednecktek

Solar Wizard
Joined
Sep 8, 2021
Messages
5,444
Location
On a boat usually.
So I know a little about batteries, but I've never found a comprehensive list on the pro's and cons of each battery type, so I thought I'd just poll here for input and any corrections, and info that I don't have. It may be a good to add into the FAQ option in the future too.

To start:

FLA - Flooded Lead Acid:

Pro's: Charges in really cold weather, super cheap per watt, handles temperature fluctuations better than many other types

Con's: Limited lifespan of 3-5 years best case, only a max of 50% discharge rate so cost x2 per Usable Amp Hour, requires maintenance, releases flammable gasses, very heavy

AGM - Absorbed Glass Mat Lead Acid:

Pro's: Charges in really cold weather, handles temperature fluctuations better than many other types, no maintenance required, longer average lifespan than FLA's

Con's: About 3x as expensive per Amp Hour than FLA's, similar weight to FLA's, Limited lifespan of 5-10 years best case, only a max of 50% discharge rate so cost x2 per Usable Amp Hour

Gel Filled:

Pro's: ??

Con's: Same as AGM? More expensive than AGM

LiFePo4 - Lithium Iron Phosphate:

Pro's: Deep discharge cycle, average 80% available power, very light, can be made to any size/rating at home, very long service life

Con's: Expensive per Amp Hour, requires Battery Management System to roll your own, does not charge below freezing temperatures,


OK Guys, fill in the blanks!
 
FLA battery supper tough very forgiving
These can last longer then 5 years I have a set that is going on it’s 7th season
and my neighbor has a set 24 units that where changed out at year 10 and some are powering his garage now
maintenance starts off small and grows over there life span .
It takes me a hour to check my battery and fill them up I add about 11/2 gallons every 3/4 months
the gassing is no big deal my charge controller turns on a small fan at 58.5 volts automatically
the fan is made for this purpose

agm
you can charge faster with more amps , they can’t spill out , you still need to check your cables every 3 months
you still need a venting fan and battery box
agms are good battery’s and can deliver more power then fla but don’t live as long
and can be over charged to death

gell
slower charging can be over charged easily will take more amps and charge faster then LA battery
I use these on my sail boat can be tipped up side down .

LP4
These are still new, look cool
most of the posts on this forum are about people trying to get them to work Or buy them ?
We will see how they last 10 to 20 years ? Or will the Chinese Bjs die 13 days out of warrantee
And murder the battery’s
them not working at cold temperature kill them for me .
 
Not really telling me what I wanted to know, most of the links are about the different pre-built battery pack options available, but not why I would spend the money on Gel over AGM's or what kind of Lithium's I can use in cold weather or anything like that. At best each link can give you a little info on one product, but nothing that really applies to the beginner or hobbyist.
 
At best each link can give you a little info on one product, but nothing that really applies to the beginner or hobbyist.
Maybe a good indicator is that the guy behind the counter of the local battery retailer I visited for some lugs and to whom I enquired about the readymade LiFePO4s on display stated something like this '' we can not keep up with the demand... little interest in the other types"
 
My FLA batteries did not get that memo.

And that's why I asked. Everything I've seen says that with daily cycling you'll only get about 3-5 years and if you want a longer life span you need to go to AGM or Gel filled.

And the guy behind the counter at my battery place in town is always picking MY brain about this stuff. There's not a lot of solar interest in farmland rural Western Washington due to weather and cost so I end up being the "Resident Expert" out here.

Over near (well, only an hour drive away) my camp there's an "Off Grid" store... it's a sad joke. It's great if you want hipster camping gear, but they can't comprehend needing more than a flexible panel with USB charging. I bought the largest panel they had available for doing my shower pump, I hope 60w is enough. :/
 
And ... Lithium Titanate cells.
30 000 cycles (!!)

Here mine: it works for cooking (180Ah/24V to 220V/2000W max) and for (partial) EV car charging
 

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Lithium is much cheaper over time, but has higher up front cost.

That would be a much better way to discuss its cost pros and cons.
 
Maybe a good indicator is that the guy behind the counter of the local battery retailer I visited for some lugs and to whom I enquired about the readymade LiFePO4s on display stated something like this '' we can not keep up with the demand... little interest in the other types"
Depends on your local battery guy.

Some of them refuse to admit lithium exists and will argue to the death that lead is superior in every way.
 
Lithium is much cheaper over time
It really depends on use case. I'd say if you replace over time with as cycle count increases then that'd be more accurate.

If you only expect to need a cycle count in the dozens to a hundred or so (e.g. as a backup system) there seems little point in overspending to have thousands of cycles you won't use.

I know the lead in batteries is highly recyclable at end of life but I have little idea about end of life recyclability for LiFePO4 or other lithium chemistry batteries.
 
It really depends on use case. I'd say if you replace over time with as cycle count increases then that'd be more accurate.
Truth

On the other hand when the price of entry is low enough allowing other areas of savings then one could conclude that fla is less expensive.

Thirdly, for small watt systems, A), and if you’re in a seasonal freezing environment, B), flooded lead batteries can make sense. My five batteries cost much less than one cumulative year of powerco watts, they’re three-ish years old, and no sign of degradation. You have to do the math on how things work for you and not just $$/wh to purchase X batteries. At day one for me three+ years back Lithium wasn’t economically possible for me (for cash). Lithium is possible now but at my current use levels it makes no sense. Yet anyway.
 
You're wright:
For lithium it's cost (much) more.
Really ? here a lead battery from Victron cost more than 350 for 12V180Ah so, for my application, it cost about 700 ($ or euro).
I bought those batteries first. If you don't use them they will survive ;) . Here they have 5 years old.
Here I'm not connected to public 220 voltage, it's perfectly autonomous but I just come for week ends and holidays.
So lead batteries only survived because I don't really use power, they just power 4G camera system and a few more.
With my new applications, if I need to cook or charge my car, they will die quickly.
So now I have two systems: one with classic lead batteries, one with titanate cells.
Titanate has the big advantage for cycles life, temperature limit and , with my pack, a 1000 amp discharge capability !
For cost:
Victron battery=700
Yinlong cells: about 2500

If you look at titanate possibility and lifetime, I think titanate looks a better choice.

But, of course, for big capacity price would be scary.
 
It really depends on use case. I'd say if you replace over time with as cycle count increases then that'd be more accurate.

If you only expect to need a cycle count in the dozens to a hundred or so (e.g. as a backup system) there seems little point in overspending to have thousands of cycles you won't use.

I know the lead in batteries is highly recyclable at end of life but I have little idea about end of life recyclability for LiFePO4 or other lithium chemistry batteries.
Yes.

That, and "literally can't afford it right now" are the only cases where I would advise lead over lithium.

Even when temperature is a factor, as you can resolve that with a bit of effort.
 
It’s a never ending debate, true.

Nevertheless, for smaller systems they are dependable and work for quite a long time.

Lithium types have many advantages over lead types. No doubt. Dismissing lead entirely is not yet the only answer. That’s coming, we’re not there yet imho. Educated choices are the best, however, not blanket answers.
 
With FLA bank sized for 3 days without sun (so most nights cycle 15% DoD), users of forklift batteries or Rolls Surrette report lifespans of 15, even 25 years.


My selection was SunXtender AGM for a relatively small bank (70% DoD overnight), because it is for occasional power failures. Higher cost per Wh, zero maintenance.


If you use LiFePO4 or other lithium, I think you should set low-temperature charge disconnect according to maximum "C" rate your system can charge to. Ambient 25 degrees C within some range, many accept 0.5C. If near freezing like 10 degrees C, max charge rate around 0.1C (check your battery's documentation, and look elsewhere if charge current vs. temperature isn't documented.)

For lithium, BMS must be sized to handle max continuous and surge current. Lead-acid, it mostly affects voltage drop and usable capacity.
 
On the other hand when the price of entry is low enough allowing other areas of savings then one could conclude that fla is less expensive.

Yes the opportunity cost needs to be considered.

Having lithium means I could do things I would prefer not to with the SLA, e.g. regular deeper cycling. This means the cycle count goes up and the $ equation improves for lithium.

I could for instance have installed LiFePO4 (instead of my SLA bank) and then use that capacity to take many circuits (mostly) off grid, as well as provide outage coverage.

It would cost me about an extra $2k for a DIY Aliexpress (ugh) bank of comparable useable capacity. Plus the rest for BMS, and appropriate housing of lithium. Say $4k for a pre made 48V battery system, everything built in.

In my case, due to the grid tariff regime in play, the regular cycling option lithium enables can save me maybe $200/year in energy costs. It's not really worth it for $ reasons.

But I need backup so SLA it is.

If I do such a thing it will be for hobby fun than for saving money.
 
Another advantage of LFP vs FLA is charge efficiency. Solar feeds into LFP more efficiently.
 
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