Guys,
I use a 32 amp computer power supply and charge 4, 6 or 8 1800mah bats at one time for my little kids traxxas rustler.
I simply use a 5 amp diode bridge on each and select whatever charge current I want with a simple door spring (This serves as a high power resistor. To turn the supply off, you just switch that one wire from ground.
I don't have pictures, I'm new here. But I may take some this weekend to post here if i have time.
It will charge 4 in about 25 min. or longer if I choose.

Never use this method and charge your bats too fast, they will not last very long if you pump 4+ amps into them. But it works very well if you charge at 2.5 or 3 amps and keep a close eye on the charging. It works just like the cheap chargers that cost $29.00.