[MPaulHolmes]

I've done voltage monitoring before, where it only closes the contactor if dv/dt = 0 and v is nonzero. It makes the board bigger, and the voltage monitor circuit adds another $25 or so. It aldo brings high voltage onto the control board. I'm just now finally done with placing the components, and mostly done with routing, and I don't think I could keep the controller the same size as the dc if voltage monitoring were included. There are alternative precharge methods. You could have the precharge wire go thru a hall effect current sensor. If the current never goes to zero, then precharge has failed (or precharge resistor failed open would show up as a different current feedback signature than exponential decay.). What some people do is monitor pack voltage at the cap in the car.