Motorhome Deep Cycle Battery and Solar Panel Charging Connections in Parallel for 12 Volts

Updated 02/17/2020 | Published 02/16/2020

Question:

I have just replaced the 12 volt deep cycle house battery on my MH. I have decided to add another one same as the new one. Can you confirm that I should wire them in parallel and that I need to purchase two extra cables one positive one negative to connect them together? Also, I have a solar panel, where do I attach the positive and negative alligator clips in order to charge the batteries correctly? Thanks for your help.

asked by: Henry

Helpful Expert Reply:

Wiring batteries in parallel allows you to get additional amperage like you are wanting without changing the voltage. So you do need to wire you new "battery bank" in parallel so that they output voltage is 12 volts and matches your motorhome. I attached a picture that shows difference between wiring batteries in parallel and in series. You do basically just need two jumper wires with a heavier gauge like 00 to make the connections.

If your solar charger setup just has two wires to run to a battery you'd connect them to the battery bank like the picture shows using the main output connections so that both are charged together. So not the connections for between the batteries but the connections that would run to the chassis ground and MH electrical system.

expert reply by: Jameson C