Quick update: The post on vedder.se forum didn’t turn up anything material in relations to the failure. I found out in passing that the heatsinks I’ve added only have cosmetic value but are not playing a significant role in keeping the VESC cool.
Anyway, I’m now suspecting the soft switch: Does anyone know what would happen if the soft switch opened the circuit after I started braking, for instance because it’s overheating? would the current generated by the braking continue to power up the VESC until it blows up because this current has nowhere to go? Would that be consistent with the failure that I experienced?
Equally, what if the power switch kept the circuit closed but temporarily prevented battery regen for some reason, would the result be consistent with what I got?
Specs of the soft switch here in case it helps. http://wiki-en.rc-electronic.com/index.php/SPS_SafetyPowerSwitch My model is the discontinued SafetyPowerSwitch 60V 60/120A.
Any further help to understand what’s wrong with our design would be greatly appreciated.