I picked up two of the HP DPS-1200FB for $40 shipped on eBay. Took me 20 minutes to solder on bullets, and adjust the potentiometer inside to get a solid 12.8V. I spent $10 on a pair of computer power cords, and 2 1000ohm resistors. I already had the bullet connectors.

To confirm that it was working properly, I hooked it up to the electric tongue jack on my cargo trailer, and used a clamp-on ammeter to measure current during operation. I got a maximum of 68A @ 12.8V (870W)......the power supply didn't limit the amperage. That's just the max it took for the motor to lift the trailer tongue, while hooked to the hitch on my truck.

I won't do a fancy wrap on them because they'll be mounted in their own cabinet in my trailer, but for less that $60 total, I've got enough power to handle any charging needs I'll have, plus have enough surplus to power the car stereo and amp I'm putting in.

Here's a link to an article I found that gives really good instructions on how to set them up for RC, or other use.
http://www.rchelination.com/setting-...-power-supply/