[Borg3]

likely be LFP? I think those batts are already available. The problem is they arent that great. Power density is low, they are advertised for 2000 cycles so I guess reallife is sth like 1500, so around 5 years only. We really need great bettery innovation with decent lifetime (minimum 10 years, 20 years preffered) and decent energy density. Once that will kick in, we could really start smart grid revolution.

[jakedata]

I am watching performance of the new LFP battery. Weight is not an issue in a stationary installation like mine, longevity and ruggedness are everything. The space is unheated throughout the winter and cold has done terrible things to previous batteries.

So far the one LFP battery I have deployed has been operating properly but there were some initial compatibility issues - my solar regulator did not interact well with the BMS despite alleged compatibility. That cost me several hundred dollars in downstream equipment damage due to voltage surge.

I am watching the new solid-state lithium batteries with great interest.

[thebruce87m]

What about sodium batteries?

> Even under frigid conditions, sodium-ion batteries can maintain a high degree of ion mobility within their electrolyte. This increased mobility ensures that the battery can continue to deliver reliable performance when temperatures drop.

https://nadionenergy.com/why-sodium-ion-batteries-perform-we....

Or is it temperature cycling that causes your problems?

[jakedata]

Sodium batteries aren't exactly commodified yet, LFE is readily available and not terribly expensive.

For the most part I don't actually need batteries that work in the freezing cold, so much as survive it unmaintained for months at a time. I had solar panel damage last winter that allowed one battery to discharge enough to freeze. That is fatal to a standard flooded lead-acid battery.

If my test battery survives this winter then I will consider using the same type to replace lead-acid ones as they age out.

[Borg3]

Oh I read the wiki article about them. Looks interesting indeed. Decent density, they claim 10000 cycles so if its real world 5000 cycles to start with thats solid 10 years!

[eternityforest]

Lithium Titanate will probably last 20 years. It's just expensive. AliExpress sodium ion batteries are claimed 4k to 6k cycles, no idea if that's real but it's cool to see stuff happening there.