So hostile,
Ok so the cost for one module would be around 6USD, that's control chip, inductor, mosfet, diode, and some resistors. The cost of a gate drive chip is around the same cost as the control chip and I would need a diff comp to ensure I wouldn't exceed my inductor current, so that works out a little more and increases my circuit size. You did not read my previous post, each module will not run on it's own, the current control will to ensure no inductor is overloaded, but a main microcontroller will control all of the modules keeping them 18 degrees apart from each other while maintaining the same duty cycle in all of them, so they should be more or less balanced.
Hi Les, that was the original plan but if my project doesn't work I have four batteries laying around, plus they're pretty expensive. My other issue is that the maximum voltage is 45V and fresh car batteries will exceed this, three batteries aren't enough either. RC Li-po's are another consideration but they just don't last very long.