Looking For Way To Charge Trailer Battery From Vehicles Trailer Connector
Updated 10/30/2025 | Published 10/13/2025
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Question:
Im looking for a way to charge a battery group 31on a trailer from the vehicle trailer connector. Do you guys have a device to help out with that? Looking for something a little bit better quality than a trailer breakaway charger
asked by: Kyle
Expert Reply:
Hello Kyle, thanks for reaching out. The 12 Volt auxiliary terminal on your 7-way connector can be used to keep the battery on your trailer charged.
You will need to run a 10 gauge power wire like # 10-1-1 from the 12 volt auxiliary terminal on the 7-Way trailer connector on the trailer to the positive terminal on the trailer battery and ground the negative terminal of the trailer battery to the trailer frame. This will allow you to maintain a charge on your trailer battery, it will not charge the battery from a discharged state.
To be able to fully charge the trailer battery from a discharged state you would have to use the CTEK Multi US 7002 12-Volt Universal Battery Charger, part # CTEK56353. This charger can be used to fully charge the battery and then you can maintain that charge with the vehicles charging system.
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Curt RVI Series Breakaway Wireless Adapter for RVibrake 3 and RVibrake 4
- Accessories and Parts
- Flat Tow Brake System
- Breakaway Kit
- Wireless Adapter
- CURT
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Jesse M.
10/30/2025
Hey Kyle, how did things go with charging your Group 31 battery using the 7-way connector and the CTEK charger? Your results could really help others trying to keep their trailer batteries topped off on the road.