Using a double pole switch in the ON position I imagine both CA would get the same readings, a total of both batteries
In the OFF postiition I would get readings as I do now, a seperate readng on each CA.
Gary, As you're using a single throttle, your batteries are probably already joined by the negative terminals, albeit through the thin black throttle wires. If you join the battery negative leads together permanently with some heavy duty cable, you would only need to use a single pole switch on the positive leads to simply connect or isolate the batteries.
With the switch in the ON position each
CA should still have different Ah, Amps and Watt readings etc. for each motor, but the voltage readings should be approximately the same on both.
You would need to add the two Ah readings together and then divide this figure by two, to determine what each battery has used.
For example, if after a run the front showed 5Ah used and the rear showed only 3Ah used, then 5+3 = 8, and 8/2 = 4, so 4Ah would have been used from each battery if they had been connected in parallel throughout the entire run.
It might not be a good idea to switch the batteries together if their voltages were significantly different, as the higher voltage pack would instantly deliver a very high current in an attempt to raise the lower voltage pack up to the same voltage level. Depending on how the
BMS handles regen, this might cause the lower voltage battery to be subjected to a very fast charge, which could be at a much higher current than the cells are able to safely accept.
I hope this makes as much sense to you as it does to me.
Alan