Recommendation for Using a 7-Way Trailer Connector to Charge a Trailer Battery

Updated 01/24/2012 | Published 01/21/2012

Products Featured in This Question

Adapter 4-Pole to 7-Pole and 4-Pole

(660)

$61.64

10 Gauge Wire - Blue Primary - Per Foot

(104)

$1.84

CTEK MULTI US 7002 12-Volt Universal Battery Charger w/ Pulse Maintenance and Backup Power

(94)

$199.99

Question:

I am wanting to put an auxiliary battery on a fuel trailer to run a fuel pump. I would like to be able to maintain the battery by using my current 7 way RV plug on my pickup truck. Also if needed a small 110 tickle charger to charge the battery when the trailer is sitting still. Is it possible to charge the battery from a 7 way RV plug and what components would I need.

asked by: Matt

Expert Reply:

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.

I am attaching a link to the instructions on the CTEK battery charger.

expert reply by: Jameson C