Best Way To Prevent Battery From Dying While Flat Towing A 2020 Ford Ranger
Updated 07/30/2026 | Published 07/18/2026
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Question:
We tow a 2020 ford ranger and use the blue ox brake system. the brake system drains our battery. What would be the best way to resolve this? Thank you!
asked by: Lisa B
Expert Reply:
Hey Lisa, thanks for reaching out. Yep this is a pretty common issue with these brake systems. The best way to resolve it is with a charge line kit like part # RM-156-25. This allows the towed vehicles battery to draw a charge from the motorhomes 7-way. That'll be enough to keep the battery topped off and stop it from dying.
Keep in mind, for this to work, you need to have a 6-pin plug mounted on the front of the tow vehicle. There also needs to be a 7-wire to 6-wire cable connecting the motorhome to the towed. We have a kit that comes with both of those parts if you don't already have them:
- Blue Ox 7-Wire to 6-Wire, Coiled Electrical Cord # BX88206
Also, the 7-way on your motorhome must have a 12v charge circuit. Most of them do, but if yours doesn't, you can use the motorhome side charge line kit part # RM-156-75 to get that up and working.
What flat tow tail light wiring kit are you using currently?
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Gary A.
7/23/2026
I was constantly having to jump off my Jeep Cherokee after pulling it for several hours. After installing the battery charge kit, I have not had to. We even pulled it once for two days without cranking it and it cranked when I went to disconnect it from the motorhome.
Jesse M.
7/23/2026
Bill
7/24/2026
Bought the battery charge line kit, had it professionally installed and have had zero issues. We flat tow a 2025 Ford Maverick and the battery is always charged.
Peter C.
7/24/2026
Have installed it on my 2021 Chevy equinox. Unfortunately we still had trouble with battery going dead. I ended up putting a battery disconnect on it. Not sure why it didn’t work for us.
Jesse M.
7/24/2026
Tom W.
7/24/2026
I pull a jeep gc behind a Tiffin Phaeton. For years I powered the Blue Ox Patriot through the cable from the RV. When I changed tow vehicles i changed to the charge line instead. Wish i had made that change years ago!
Product Page this Question was Asked From
Roadmaster Battery Charge Line Kit for Towed Vehicles
- Accessories and Parts
- Flat Tow Wiring Harness
- Battery Charge Line Kit
- Roadmaster
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on Accessories and Parts
Patrick L.
7/23/2026
I purchased the Battery charge line kit for towing my Ford Bronco behind our motor home, it works without issue. No dead batteries on the Bronco and have towed many times. Just make sure your tow vehicle has the charge line powered/functioning as some vehicles come without it pre-powered and the wire has to be hooked up to the fuse box. You can get a 12v test kit almost anywhere and test your charge line wire to be sure the vehicle is pushing power through to the tow vehicle. Assuming your tow vehicle has the charge line hooked up, you'll be good to go with this kit as it's easy to install!