MOSFET in the bms getting hot


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ajw22

Member
Joined
Nov 16, 2018
Messages
664
i lifted the gate leg of bad FET [...] it was difficult to de-solder, so i left it like that
Make sure to also de-solder (or cut off) the "source" leg of that bad FET. Otherwise it might misbehave and not allow the BMS to stop discharging.
Also, the BMS might run too hot at 50A with the reduced FET count, so you might want to de-rate it to 45A or whatever.

the gate leg of bad FET and i measured the resistance to the the source leg. it was showing some resistance.
Just out of curiosity, how low was the resistance of gate<->source and gate<->drain (back side)?
 

ketoneenergies

New member
Joined
Oct 22, 2018
Messages
28
Make sure to also de-solder (or cut off) the "source" leg of that bad FET. Otherwise it might misbehave and not allow the BMS to stop discharging.
Also, the BMS might run too hot at 50A with the reduced FET count, so you might want to de-rate it to 45A or whatever.


Just out of curiosity, how low was the resistance of gate<->source and gate<->drain (back side)?
66 ohms i think
 
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