Cars, trucks, RVs, and motorhomes run dual 12-volt batteries for various reasons. Depending on how you wire a two-battery 12-volt system, the result can be a 12-volt system or a 24-volt system ...

NHRA rules mandate that a battery-disconnect switch be installed on the positive side of the battery. This is fine for a purpose-built race car without an alternator, but for a street car, the ...