Can 12 Volt Accessory Circuit of Truck Charge Trailer's Lithium Battery

Updated 03/05/2026 | Published 03/03/2026

Products Featured in This Question

Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 25 Amp

(88)

$484.59

Redarc In-Vehicle BCDC Trailer Battery Charger - Dual Input - DC to DC - 12V - 12 Amp / Solar 40 Amp

(25)

$260.00

Question:

I have a 2025 Ford F150, I recently installed a 320ah lithium battery in my fifth wheel camper. I am wondering if it would be safe to tow as is without a dc-dc charger or if I can use the battery disconnect on my rv to isolate the lithium from the lead-acid in my vehicle. I tend to leave home with a fully charged RV battery, I plan to do some dry camping however would have limited travel time where charging from the vehicle would be unnecessary, or not helpful. My RV is not equipped with solar. I would have to charge the battery via generator power in a dry camping scenario once I arrived. I just want to protect my vehicles charging system without having to spend $1000 on unnecessary parts.

asked by: Brett D

Expert Reply:

Hey Brett, this is a really great question. Basically if you don't use a DC to DC charger like the part # 331-BCDC1225D that you referenced the battery would only ever get to a charge of around 80 percent since Lithium batteries need a much higher voltage to charge. If you wanted to save some money on a charger we have the part # RED36TR as well which is a 12 amp charger instead. The one you referenced is a 25 amp charger.

expert reply by: Jameson C

Brett D.

3/5/2026

I’d be interested in something to install on the RV side if possible.

Jameson C.

3/5/2026

@BrettD You could use the part # GP95QR for a 10 amp charger that could install on the trailer side.

Brett D.

3/5/2026

@JamesonC What about the VN54RR? I have a lithium battery. I would just be interested in maintaining a charge while traveling and connected to the 7 way.