batteies

MrWizard wrote:




Over voltage is dangerous it can cause Thermal Runaway and fires,

If we are talking older forms of LI and not LiFePo4 I would tend to agree with you, LiFePo4 is highly resistant to thermal runaway and is hard to get to do it.

I am reading a study right now where they took a 202ah battery and put a 900 watt heating element on each side and ran full boar until the safety valve popped and it went into a thermal runaway state. It took a battery internal temperature of over 160 degrees Celsius to do it and the maximum temperature achieved during the runaway was 202 degrees Celsius. Another they did with only 1 heater but put the battery into a sever overcharged state first and then heated it until it started to run away. so while it is possible to get thermal runaway it is very hard under normal conditions, you would need the charger to fail, the BMAS to fall in a manner that still allows charging, and possible some external heat source to aid the process as the charge rate most of us will have on their batteries wouldn't be enough to spike the internal battery temp high enough.

just for a bit of context the batteries they use in teslas that people were getting cells from and putting them in their rv's will thermal run away much easier and will reach 600+ C temps when they do.