How do Trailer Interior Lights Normally Wire to Trailer Battery

Published 08/28/2019

Products Featured in This Question

Optronics 12V LED RV Dome Light - Double - 10-5/16" Long x 4-3/16" Wide - White Housing

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$25.08

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

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$199.99

Question:

I bought a cargo trailer and it came pre-wired with LED lights and fan. They do not tie into the wiring of trailer while being towed. There’s only 1 black wire to power the LED and fan. No ground. I’m assuming it’s grounded on mounting bracket. If I want to attached that to a battery to power it. So I just run a ground from - battery post to frame? If so, what time of battery and how would I go about charging it?

asked by: Hai D

Expert Reply:

You are on the right track. So you'd want to run a ground wire from the negative post of the battery to the trailer frame and that connection will be good. And then for powering the lights you'd run a wire from the power wire of the light to the positive post of the battery and you'd be set.

A deep cycle battery is often the best kind for trailer applications as they hold up the best over time and stay charged well. From the trailer 7-way connection you can run a wire from the 12 volt accessory circuit to the positive post of the battery and it will receive a maintenance charge.

To charge the battery once it's dead though you'll need to connect it to a wall charger like the CTEK part # CTEK56353 which can put a higher amperage charge on the battery.

expert reply by: Jameson C