Can Redarc In-Vehicle BCDC Trailer Battery Charger be Connected at Same Time As Trickle Charger

Published 11/05/2026

Question:

I have an enclosed car-hauling trailer using an interior deep cycle battery to independently operate two winches, a door/ramp, and a loading winch. The trailer is stored indoors but sees less frequent use during the winter months. I have been using a Deltran Battery Tender Plus, 12VDC @1.25A, to maintain a float level when the trailer sets idle for weeks or months. If I install a Redarc BCDC1212S e-trailer P/N RED36TR battery charger, can it be configured to accept an idle-time trickle charger?

asked by: John B

Expert Reply:

Hey John, welcome back! Yes you can continue using your Deltran Battery Tender Plus 1.25-amp charger to maintain your trailer's deep-cycle battery after installing the Redarc BCDC1212S part # RED36TR.

The key is that you should connect the Battery Tender directly to the trailer battery, rather than running it through the Redarc charger. The reason this works is that unlike AC power you can have two DC power sources connected to a battery (or anything) and it does not cause any issues. What cars do you usually haul?

expert reply by: Jameson C