So I had to replace my old pc powersupply when the fan stopped working and it fried after a few years of service, i came up with this idea a while ago, warmed up the soldering iron and got to work.
Started life as a 450 watt computer power supply, stripped it down to have a single 12v output for a charger, added copper rails for other chargers with alligator clips to run off of it, usb hub for charging phones, ipods etc :)
Has a 2 position switch between ground and the arming wire (green) for switch on and off.
Troubleshooting and Solutions
- First time I fired it up the power supply did NOTHING, wouldnt even spin the fan over. I found out that I needed to reconnect the sensing wires to the 3.3v and 5v rails respectively for the supply to keep tabs on its power output.
- Flipped the switch and it powered up! yay

.... and then it died.

Flipped the switch a few more times and it did the same thing. It would power up for a few seconds at 12.02v and then die. After some snooping, i found that I needed to load the 5v rail of the supply to get the power supply to wake up. Got a 10ohm, 10watt sandbar resistor and thermal paste(d) it to one of the heatsinks already inside the Supply, and wired it between a 5v sources and a ground wire. viola! Now she idles at 12.05v without load. Now to see what she can do.
Hooked up my Imax b5 Charger, charged a 2s lipo at 5amps, voltage at the supply was 11.94v, THen hooked up a Hyperion 6series charger, and charged another 2s pack at 5.6amps, Input voltage dipped to 11.8 then went right back up to 11.94. Then hooked up 2 120mm pc fans, still no change in input voltage :). This thing is a monster and could probably run 4 chargers perfectly fine.