how to hook up dual batteries in motorhome

Now if you really want flexibility get yourself a marine battery switch which will allow you to #1, or #2 or both together all at the twist of a a switch.

This is what is balanced and best for twin twelve volt batteries.



As it often doesn't cost a dime more to do this, I think it is worth the trouble.

If you wish to understand the "why" surf here:

correctly interconnecting multiple twelve volt batteries

Others may say it doesn't matter--but unless there is a compelling reason to not optimize charging and discharging why not do it the best possible way?

12VDC Batteries are connected in PARALLEL... Will look something like this... The balanced way is to take the negative off of the second batteries as shown in the diagram.

Don't know how old your original 12VDC battery is but alot of folks don't like to mix an old battery with a new one. It may drag down the new one to the old battery performance wise. Its best to have two batteries of the same manufacturer and the same new age to start off with for best battery performance.



Roy Ken

In parallel, Positive to positive and negative to negative.