4 ms·
I'm not sure if that affects all chemistries and compositions. If you look at the spec-sheet for e.g. the LG E63 cells used in some older EVs (notably without T
by formerly_proven 2y ago
I'm not sure if that affects all chemistries and compositions. If you look at the spec-sheet for e.g. the LG E63 cells used in some older EVs (notably without TMS), those specify charging down to -20 °C - and the owner's manuals certainly have no warnings in them that the car will implode if you charge in the winter.
- lazide 2y agoWhich is really weird. Near as I can tell, it’s just a pouch lipo. The charge currents for sub-zero are near zero amps, but are still > 0. It should destroy the cell, but apparently doesn’t? Any insight?
- formerly_proven 2y agoWell it doesn't :D At least not in a way that people complain about battery failures or degradation. On the other hand, the battery has to reach that temperature in the first place, which may take a couple days of constant exposure to that temperature.
- lazide 2y agoActually, it does and will in the right conditions. Look at page 11 of that link. I did some research, and the plating issue happens when charge currents exceed the ability for the battery to absorb them, which dramatically decreases below freezing. That is why those battery charts show dramatically reduced charge currents (nearly zero) when around freezing. That data sheet also doesn’t cover cell life in these conditions conditions. They have very high normal C ratings (hundreds of amps) which is why it is measurable and not actually zero, but reducing it to a couple amps before failure isn’t much different. If batteries aren’t failing in these conditions, it’s because of some other protective circuit, not because the battery itself is special. It isn’t.