I have had very good results with computer power supplies. If you are converting it yourself, make sure to put the load on the 5v line though. I used a trailer light and it works great. The biggest thing I have tried to charge was a 12v battery at 5 amps through a Triton charger. It worked fine for that. I have never tried to charge 24 cells before, but the Triton is rated for it.

There is a link to an excellent write up on converting power supplies at www.rcbatteryclinic.com. Scroll the left menu all the way to the bottom.

Good luck!