are these nicads?

V.

LiFePO4 Lithium Iron Phosphate, about 23-24 pounds each (which means I weigh more than all twelve of them!)

keep fire extinguishers handy...

V.

Three feet away from where I was standing for these shots, reach behind me and there we go. Oh, and there's a smoke detector on the wire shelf above everything.

While they each have a built-in battery management system I'm a bit of a coward, so while they claim eighty amp charge rates the solar controller is set to not give them over seventy, and while the battery sets' max charged voltage is fifty-eight volts (14.5 times four), the controller stops trying to charge them when they reach fifty-six volts.

gotcha...

V.

LiFePO4 batteries are MUCH safer than any nickel based lithium batteries. (NMC in particular (nickle, manganese, cobalt)). Either way, as long as the BMS keeps them properly charged, and they never get overcharged, or they don't get punctured they are not a fire risk.

LiFePO4 batteries, you can run anywhere between 0-100% and they can run around 10 thousand full charge cycles before you see a reduction in capacity.
NMC lithium batteries, they prefer to be between 15-85% in charge, and usually you get up to 2000 cycles out of them before you see 80% capacity remaining.

LiFePO4 = Lithium Iron Phosphate

thank you...

V.

Did you look into the Dakota Lithium LiFePO4 batteries? (They're pretty expensive, but probably higher quality than these)

Don't remember if I looked at those or not, just went with something LiFePO4 I could afford with all the other bits and bobs. So far they seem to be behaving themselves, and since I have run them into the ground (once) they seem to have their rated amp hour value.

https://dakotalithium.com/product/d.....solar-battery/ $900 for these.
https://dakotalithium.com/product/d.....h-12v-battery/ These are supposed to be 200Ah, but for $1700

Yeah, they are pretty expensive.

They do have these 48V, 96Ah batteries that provide up to 4.9kW of power. (I assume the rated 96Ah x 51 volts)
https://dakotalithium.com/product/d.....arine-battery/ These are $2700

I like the twelves because if there is a problem I can 'build' a set out of any four batteries (and my 2000W 'standby' inverter is only 24 volt, so I'd need to work around that too.)

$1440 for the same 4.9kWhs of power, or in my case 14.7kWhs of battery for $4320.

To be honest, I should have added a fourth set of batteries to better cover a cloudy day, and maybe two more sets of solar panels to charge them faster when the sun does shine (though right now what I have is topping off the batteries on sunny days. )

Well, you do have a 6kW inverter, so you could add an additional 12 panels for 5.88kW, or an additional 5.12kW in battery storage (four 12.8V @ 100Ah batteries). I'd say both, but depends if you want to spend $1376 plus whatever the panels cost (probably $300 each) plus sales tax

The panels at the time were right at a buck per watt so eight more is another $1700 and tax ...

I was paying around $360 each for the ones I got - just checked and they're now down to $344!

I went with the 100Ah because all the 100/200Ah ones I saw were 100A max current draw, and since the 6000W inverter might try to draw +125A I went with two (upgraded to three) sets of 100Ah batteries.

Yeah, spending $4300 is quite a bit better than $10,800.