Can Larger Battery Be Used for Trailer Breakaway System and Interior Lights

Question:

I am looking to mount this on a trailer, but would like to use a Group 31 AGM battery instead of the smaller 12v battery, because I am going to run some LED Strip lights inside of my bike trailer and would like the lights to run while I am traveling so I can check on my camera that the bikes are still secure. Can you tell me if this system will work to not overcharge the battery from my truck, or should I use a different system?

asked by: Power E

Expert Reply:

The Tekonsha Push-to-Test Trailer Breakaway Kit # 50-85-313 that you referenced includes the small 12V rechargeable battery and charge wires that will be connected to the 12V circuit on the trailer's 7-Way. You could physically use the system with a larger battery (it wouldn't be overcharged) but I do not recommend using the larger battery for both your trailer's interior lights and the breakaway system.

This is because for safety reasons you really want to have a dedicated battery in charge of the breakaway system to reduce the change of it becoming depleted due to power draw from other sources. Many state DOT regulations actually state that a breakaway system needs to have a dedicated battery.

Your best option is going to be to use the included battery for the breakaway system and have a separate Group 31 AGM battery for the trailer's interior lights (and anything else you might need it for).

expert reply by: Chris R

Daniel

2/13/2025

I have a separate brake control, in my enclosed trailer. so that my lights will work with the truck not connected. I am planning to go to a powersports battery. Any reason the brake control charger, not actually being used for the e-brake, wouldn't function ok. I'm just looking for a longer life of the lights in the trailer and don't care that it would take a while to recharge because of a reduced charge rate. I'm just using the controller as a battery charger