How to Use Redarc BCDC 1225D to Charge 2 Different Amp Hour Rated Batteries

Updated 06/24/2021 | Published 06/22/2021

Question:

I have the Redarc charging my 80Ah LFP battery connected to two Engel fridges while driving. I also have a separate 125Ah battery not connected to anything. All connections are made with 6AWG and 50amp Anderson connectors. As I drive, can I also connect the 125Ah battery to charge in addition to the 80Ah as it runs the fridge? Purchased the Redarc from you last year and love it! Thank you

asked by: Greg L

Helpful Expert Reply:

In order to charge 2 batteries with the Redarc In-Vehicle BCDC # 331-BCDC1225D you would need to wire both batteries in parallel so that you're essentially creating a 205Ah battery that can be charged while you drive. To connect the batteries in parallel you'll need to connect the positive terminals of both batteries to each other using a jumper wire and do the same with the negative terminals.

You can wire two batteries in parallel if they have different amp hour ratings, deep cycle or regular. You wouldn't mix two different battery types like gel and lead acid though. You will want the batteries to be of the same type; 2 gel, 2 lead acid, 2 deep cycle and so on.

expert reply by: Erik B