LiFePO4 self heating batteries in parrallel

[Refuse1]

I am trying to figure out how it works when you have self heating batteries in parallel. The way I understand it is that a self heating battery will only use incoming "charging current" to heat the battery if it is below the safe temperature to charge. So lets say you have 2 of these batteries in parallel. What is to stop the 2nd battery from providing the "charging current" to turn on the heater of the other battery, thereby each battery running down the other battery while trying to heat each other.

 

[HighTechLab]

The potentials are the same, so no current flows. It usually takes about .5v of forward voltage to overcome the body diode of the open charge FET that then feeds into the heating circuit...so in other words, your second battery would have to be .5v higher than the one that is shut down to feed current into it.

 

[Refuse1]

Thanks High. That explains it since in theory if the multiple batteries were in parallel they would have to be basically at the same potential and would not trigger the heat circuit Makes sense now..