I was also wondering about the voltage sensing for this. From what I can see from the schematic and layout on http://roadwarrior.free-man.com/can/...anBusway.shtml
, there are two hall-effect devices on either side of a current sensing coil, and I assume this measures the main DC supply from the battery pack. I don't know the exact voltages and currents involved, but I would imagine at least 400 amps and 600 VDC (240 kW) since IIRC you have something like a 500 HP motor on your RV.
So, my first question would be how the PCB can handle the 400 amps of current. And my second question is the voltage and power rating of the resistors for your voltage sensors. If the hall effect sensors have a 40 mA coil, then the resistors would need to be rated at 600*0.04 or 24 watts, and also must be rated for 600V, which may require several in series.
There are hall effect voltage sensors which operate on 10mA which would reduce the power to 6 watts. http://www.bbautomacao.com/home_hall..._CYHVS025.html
Another question is why it is necessary to measure the input and the output, since there is only the sense coil in between, which should drop only 100 mV or less (and even that is 40 watts).
If you have external shunts or voltage dividers, then I can understand how this might work. But otherwise I, too, am stumped.