Best Way to Safely Charge Trailer Batteries from a 2015 Ram 1500  

Question:

Expert Reply:

Hi Glenn, the best way to safely and reliably keep both of those trailer batteries charged from your 2015 Ram 1500 is to go with a Redarc DC to DC charger.

I recommend the Redarc In-Vehicle BCDC Battery Charger part # 331-BCDC1225D to safely charge your batteries from your 2015 Ram 1500. This is a really solid, set-it-and-forget-it solution because it takes power from your truck and converts it into a proper, controlled charge for your trailer battery, so you’re not risking overcharging, undercharging, or putting strain on your truck’s electrical system. Since you have two separate trailers, it will charge whichever trailer is plugged into the charge line at the time.

In the future, you could also add a solar panel like part # RED76VR as another way to keep your trailer battery topped off. That gives you a nice option to maintain a charge without relying on your truck’s alternator, especially when the trailer is sitting for a while or not being towed regularly.

There are also more cost-effective ways to maintain a charge on your trailer batteries. One common approach is to activate the 12V circuit on your truck’s 7-way by running a length of 10-gauge wire like # 10-1-1 through a breaker like # 9510 from the truck battery’s positive terminal to the 12V pin on the 7-way (located at the 1 o’clock position). From there, you would connect the matching pin on the trailer side to the auxiliary battery.

This setup can work well for maintaining a battery that’s already charged, but it typically won’t provide enough amperage to recharge a depleted battery. It’s also a more traditional method, so it doesn’t offer the same level of protection or charging precision for your vehicle and batteries as a DC-to-DC charger.

Another alternative is using a shore power charger like the CTEK MULTI US 7002 part # CTEK56353, which is a great option for keeping your batteries topped off when the trailer is parked and not connected to your truck.

If you want something simple and reliable while driving, the Redarc is definitely the way to go. Out of curiosity, what are you primarily using your dump trailer and winch for?

expert reply by: Heather A

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Glenn C.

4/9/2026

Heather: FANTASTIC REPLY! As soon as I clear this massive project I am on, I will order the equipment from you guys and get started. I am done looking elsewhere for my trailer needs. Thanks Glenn

Heather A.

4/9/2026

@GlennC I really appreciate you taking the time to say that. That seriously means a lot. I know how overwhelming some of this stuff can get when you’re in the middle of a big project, so I’m glad I could help make it a little clearer. Whenever you’re ready to circle back around to it, just let me know and I’ll be happy to help you get everything dialed in for both trailers.