bing tracking image
Q & A Icon

Can a Breakaway System Battery Charger Charge a Car Battery to Power a Trailer Mounted Winch


I want to know if the 5amphour trailer battery chargers can be used on a normal 12v automotive battery or deepcycle battery. My application is that I have a 18 flatbed autohauler that I want to spruce up. I want to install a deep cycle battery on the trailer in place of the small breakaway battery, in order to power a 8000lb winch on the trailer in addition to the breakaway. I would like to install a charger that will power from the towvehicles aux 12v circuit without overloading the wiring trying to recharge a severly drained battery. Will the charger limit the amperage enough to do this safely? Currently i run jumpercables to the tow vehicle to power the winch, and my breakaway battery is standalone and needs to be manually checked and replaced periodically. The tow vehicles are a 2009 Suburban and/or a 1997 Toyota Tacoma. During this retrofit I plan to change the trailers and Tacomas wiring from a small 6pole round currently on the trailer/tacoma, to a 7pole large round for the factory suburban plug.


Expert Reply:

There are a couple of different things going on. First, a 12 volt circuit from a trailer connector will not be able to charge a battery, it will only be able to provide a maintenance charge, maintaining the charge level of the battery but not adding anything to it. While it may be sufficient for smaller breakaway batteries, it will not be sufficient for a 12 volt automotive or deep cycle battery.

I recommend using a dedicated battery for the breakaway system, like the Engager Trailer BreakAway Kit, # 20099. or a similar kit depending on how many axles and brakes are on your trailer. The Department of Transportation requires a full 15 minutes of braking for a breakaway system and a drained car battery with a maintenance charge cannot provide that.

To power the winch, there are a couple of different methods. I have included a link to an FAQ article that should help. You will need to look at the second section called Wiring a Trailer-Mounted winch. There are 2 options.

For the wiring, since the Suburban is the only vehicle with a 7-Way trailer connector, you can use a 7-Way to 6-Way adapter like # 47565, on it and leave the wiring on the Toyota Tacoma and the trailer as they are.

expert reply by:

Products Referenced in This Question

Product Page this Question was Asked From

Q & A Icon

Similar Expert Q&A Pages

See More Q&A Expert Answers >>