Charge line kit to Replace Brake Buddy Battery Charger kit 39339

Updated 05/10/2026 | Published 05/07/2026

Products Featured in This Question

Roadmaster Battery Charge Line Kit for Towed Vehicles

(1435)

$51.85

Roadmaster Battery Charge Line Kit for Motorhomes

(152)

$56.90

Question:

I know Hopkins is in bankruptcy now. What do you recommend to replace their Brake Buddy Battery Charger kit 39339?

asked by: Michael C

Expert Reply:

Hi Michael, that’s a great question and you’re not alone in running into this with Hopkins getting harder to find.

The closest and most reliable replacement is the Roadmaster Battery Charge Line Kit for Towed Vehicles part # RM-156-25. It does the same core job of keeping your towed vehicle battery charged while you’re flat towing so your Brake Buddy or other supplemental braking system doesn’t drain it.

The original Hopkins 39339 was more of a managed battery maintainer designed specifically for setups like yours, but in real-world use most people have moved to a simple charge line like the Roadmaster and had excellent results. It pulls power from the motorhome and keeps your toad battery topped off consistently.

One thing to keep in mind is that this kit does require a charge line from the motorhome side. If your RV does not already have one in place, you’ll also need the Roadmaster Motorhome Battery Charge Line Kit part # RM-156-75 to complete the setup.

I completely understand wanting something you can trust, especially when it comes to keeping your braking system powered and ready. The Roadmaster kit is widely used, straightforward, and backed by a brand that’s still fully supporting their products, which gives a lot of peace of mind going forward.

What vehicle are you towing, and are you mostly doing longer highway runs or shorter trips?

expert reply by: Heather A

Tom

5/10/2026

I have been happy with the Roadmaster on my Jeep Grand Cherokee. I used to have a charge line directly from the RV and like the new setup much better. Easy to install and works well!

Wayne T.

5/10/2026

Hello Micheal. I recently installed the Roadmaster Battery Charge Line Kit for Towed Vehicles part # RM-156-25 on my 2025 Ford Maverick. This utilized my 2024 Isata 3’s charging system to maintain my Maverick’s battery charge. Very easy to install via your 5 pin connection. Works extremely well. I’d recommend using it.