I'm about to wire up a battery switch so that I can switch between two
batteries. (one or the other or both)
Just wondering if I should put the switch on the positive or negative?? Or
doesn't it matter?
Also, do both the batteries have to be the same age/rating??? I was hoping
to use my old battery for powering accessories when I'm stopped, but charge
it when the engine is running with the other battery.

Thanks in advance!