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—or even ...

I have been around long enough to remember when most cars were equipped with 6-volt batteries. They were cumbersome and never turned the engine over fast enough in cold weather. Then sometime in the ...