[MPaulHolmes]

I use a 300amp slow blow DC fuse in series with the battery. It doesnt' blow up with brief jaunts above 300 battery amps. They are only like $4.99 on ebay.

The arduino was switching at 1.5kHz? One possibility is that they were spending too much time in the transition between off and on at 16kHz. And under load that would be a ton of heat. Also, the gate resistors that are on the wiki are 22 Ohm. Probably way toO big for this. I tried 10 Ohm resistors with some IGBTs and they almost caught on fire. The fact that the hardware overcurrent didn't stop anything was probably because the overcurrent circuit pulls the gate (oops, base) low when an overcurrent event occurs. I think the transistors were already failed shorted by the time the overcurrent started happening. The controller has no safety built in for failed-shorted transistors.