Can Vehicle 7-Way Charge Batteries for Trailer Winch

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

Products Featured in This Question

Victron Orion-Tr Smart Isolated DC-DC Charger w/ Bluetooth - 3-Stage Charging

$243.95

Victron Orion XS DC/DC RV Converter - 12 Volt/12 Volt - 50 Amps

(1)

$328.10

Question:

I have a trailer winch wired to two 12v deep cycle batteries wired in parallel. I have been charging them via 120 volt charger. I am thinking about charging them off of the tow truck. Should I do anything other than wiring them directly to the hot pin of the seven pin connector?

asked by: PAUL E

Expert Reply:

Hey Paul! You can connect the batteries to the 7-way on your truck. However, the 12V from the factory 7-way is really designed to be a maintenance charge. Between the smaller gauge factory wiring and the long run from the alternator to the back of the truck, the voltage drop is significant. Because of that, it typically won’t put enough current back into the batteries to recover them after using a winch.

If you're actually running your batteries down with the winch, a DC-DC charger like the Victron Orion-Tr Smart # VN56RR or # VN93VR is the right solution. This takes the alternator output and boosts/regulates it properly so your trailer batteries get a true charging profile instead of just whatever voltage happens to make it through the 7-way connector.

What kind of truck do you have?

expert reply by: Robin H

Victron Orion-Tr
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Paul E.

3/5/2026

Thanks, I have 2017 f150 with tow package

Robin H.

3/5/2026

@PaulE you’re welcome! The Victron Orion-Tr Smart # VN56RR will be a solid upgrade on your F-150 and will help keep those winch batteries ready to go whenever you need them.