So... I gave up on the 150A version. It looked promising and I could easily pull 500A through it but the idea of pairing up two TZ85as is inherently flawed.

It all works fine until one of the ESCs browns out. And if you happen to be using very low inductance motors, like I am, this can happen even at very low PWM duty cycle. If the motors are stalled even at low throttle this can cause the input voltage to drop very low and the ESC to reset. As there is communication between the two paired ESCs to ensure they are synced and running properly this means that if they don't reset at exactly the same time or if one powers back up first they can enter a situation where there is shoot through in the ESC causing it to blow up.

There is no way to solve this with software. It could be solved in hardware but its easier to just use a different ESC. For the middle they are 2 85As running on separate brushes. I do not know how much current is coming out of the batteries but I think it is a lot. The 8AWG wire from the batteries is too hot to touch after just a few minutes of driving. So it will be interesting to see what happens.

Steve