Just got a good deal on a used 26 foot trailer. It came with a Warn winch and a battery. The battery is a size 56 Champion 640 cranking amps. My question. . . Can I charge this thing off my truck battery with jumper cables (truck running of course)? I currently don't have a trickle charger and figure after a few uses of the winch, I could charge it this way. Any draw backs to doing this?

Any one have some better way of charging the trailer battery without the jumper cables (cable running from the tow vehicle)?

It's common practice to run a charge line from the tow vehicle's battery to the connector at the rear bumper. If you are using the small 6 pole connector, the center pole is the one usually used. If it's a large RV style 7 pole, use the pole labeled "Black". Installing a 20 amp circuit breaker near the battery is a good idea. Use 12 gauge wire.

Thanks for the reply. I wired everything with the 7 Pole connector. Includes Brake wire. I had no idea that the large black wire was used for this purpose. So as long as the vehicle is running it's pulling a charge off the truck alt.
Thanks again,
Joe

Something else to consider: Since both batteries are tied together, they can die together. You might consider a battery isolator. You can make a cheap one using a standard 12 volt Bosch type relay.

Larry