So far, I use a separate battery charger to charge my trailer winch battery. I would prefer to wire it into the trailer wiring that plugs into my tow vehicle, but I suspect it could overload the wiring in my 2005 Chevy Silverado.

I am sure there is a way to limit the charging rate so it will keep the trailer battery charged while towing. Does somebody offer a kit for this?

How big is your trailer wire?
How much load is on that wire (running lights circuit)? How much capacity is left?
How many amp/hours is your battery?

As you can see, the idea is great, but everyone's situation is different.

Why don't you run two separate wires (pos & neg) from your battery to your trunk area, with a fuse on the battery +? You can use #10awg stranded copper wire fused for 30-amps, and plug into your trailer. (I would put a diode in series, just to make sure current is going in only one direction.)

Having a hot wire with some capacity is a great thing to have in your trunk area. When you aren't charging your battery, you can use a 300-watt inverter to make 115-VAC. Want a real good trouble light? Pull it off the wall in your garage, and plug into an inverter. Trouble lights are usually long enough to reach under the hood, from the trunk.

Charging a battery (using your skinny existing wires), means you will be driving for a VERY LONG TIME with your lights on. It is more practical to charge at home, or do the separate wires.

I already have a dedicated battery to run only my winch. I just want to know if there is a way to keep it charged from my tow vehicle's alternator.

Yes. You should be able to run a wire from your plug that will keep it charged. I'm going to hook mine up that way this weekend. A friend of mine hooked up his trailer battery this way and the charging system from the tow vehicle kept kept the battery charged.

Everything depends on these factors, and you haven't answered any of these questions.

I know you have a battery that's dedicated. When you use the winch then start your vehicle, the battery will draw current to recharge. How many amps is your tail light fuse? Better buy extras. By the way, your vehicle and trailer lights have to be on too, so subtract that from your fuse capacity. If you put a bigger fuse in, the wire will be the new fuse, and it will fry inside your vehicle.

Most car batteries rate around 50amp/hour. 1amp X 50hrs. charges this battery (from completely dead). If yours is a 10a/hr., one amp will take ten hours, 2amps take 5, and so on.

Charging with one amp, you will be driving with your lights on for a very long time, just to charge your battery.

Your tail light circuit wasn't designed to run lights and charge a battery. I do not recommend it but hey, it's your vehicle. Running a separate fused circuit won't jeopardize your vehicle's electrical system and you'll have lots of aux. power to run without a separate battery, if you like. Hope this helps.

Simplyconnected,

I do know better than to use the circuit for trailer lights. That is why I didn't answer all your questions.

I simply want to know if anyone on this forum has done this for their tow vehicle, and if there is a kit or instructions on how to do this for a stock 2005 Chevy Silverado.

I fully expect to run a dedicated heavy wire from the battery or alternator, I just want to know what other devices I need to prevent problems.

Maybe I misunderstood your question. Do you have two spare pins in your truck's receptacle? If they are large enough, all you need is wire and a fuse.

Agreed. There is an "always hot" lead on the trailer plug. However, I would rather limit the amperage and charge direction with a diode and a breaker rather than a fuse that would require replacement each time the load limit of the wire is exceeded.

I still would expect someone to have a kit for various tow vehicles to charge travel trailer batteries etc.

mark take it to an auto elictician they will do it easy , it wont over load your current wiring . i had a caravan done here in NZ some years ago,as i wanted to keep the battery for the lightng system charged , and never had any problems . if it can be done here i'm sure you will have no problems getting it done in the US.

Mark,

I've used this charging module to charge the winch battery on both of my trailers. Easy to install yourself without professional help. I also installed a battery cut off switch to avoid any draining of the battery during prolonged storage. The modules aren't cheap but they limit the current and work great.

http://atkinsonelectronics.com/product_pdfs/TBCM-40A.pdf

SolidAxle,
Exactly what I was looking for!

Thanks a heap...