In the ESS context, unless you are buying bare cells, I don't think it's possible to buy an LFP battery without built-in heating.

Well, I have 15kwh of batteries in a shed (powering my internet connection and this computer, actually). The are mostly in a shed for convenience- I'm not too worried about a fire, personally.

You can charge them when freezing, but you can discharge them while freezing.

Discharging them causes their internal temperature to rise.

Last winter (I'm in the desert in CO at about 6k feet, with temps in the single digits at some points) my graphs say that they never failed to reach 40-something degrees and charge.

Maybe there are other issues I don't know about, but I certainly hope they work as well this winter as they did last winter.

LFP have a significantly more stable battery chemistry. Much more abuse tolerant and less likely to suffer thermal runaway. You'd get LFP cells so you won't have to store them in the shed due to fire safety. And while sodium ion batteries would be happy in a frozen shed they're supposed to be even more stable.

Anyway,sodium ion taking off explains the recurrent deep sales for LFP power stations. Which might still be overpriced if there developments hold up.

Most solar battery banks have moved on to LFP as of last year. They work to 10f if I'm not mistaken. Booting it up before the cold sets in will ensure it can run.

Most BMS support heating pads, but regardless sodium is superior in cold and will win that segment long term.