Submitted 2 weeks ago by schizoidman@lemm.ee to energy@slrpnk.net
https://www.ess-news.com/2025/04/30/biwatt-releases-4-5-kwh-sodium-ion-battery/
According to the manufacturer, up to four modules can be stacked together for a total storage capacity of 18 kWh, and up to four stacks can be connected in parallel for a total of 72 kWh.
Why is this?
I always thought you could connect as many batteries as you like in any configuration the voltage and storage required.
In theory, you can stack cells any way you like, and calculate what the current, voltage and capacity should be. However, those simple calculations don’t consider what the effects might be. Due to material limitations, only certain voltages and currents are safe. Go beyond the limits, and things begin to burn.
Also, these are modules, not cells. Each module probably contains some sensitive electronics that certainly can’t handle any random voltage or current. My guess is, that’s where you’ll find the first bottle neck.
Probably just an invertor input voltage limitation.
In the batteries because I thought hooking them up in parallel increases the storage indefinitely without increasing voltage.
I can’t answer the why but there was a warning sticker on my new lifepo4 batteries with similar limitations. So not chemistry dependent.
Holy shit those are pricey.
How do you like them?
Hamartiogonic@sopuli.xyz 2 weeks ago
Consider cross posting to !batteries@sh.itjust.works