Right now I have a 10/2 amp automatic battery charger (sears) feeding an RC car battery pack charger (old BC100). If you push the start button on the RC charger, it puts out a peak voltage suitable for the number of cells on the dial. I wedge a piece of plastic tubing on top of the button and dial the current where I want it. It can do 10 amps also, but I have trouble fitting more than about 4 amps worth of parts in my Tupperware tub.
This also seems to keep the automotive battery charger from cutting back automatically, even though I have never seen it perform that function. I've read that it can be a problem.
I had a 13.8vdc 12amp supply, but the regulator went out and it started supplying 18vdc in the middle of a part and must have burned one side of the transformer, since it just runs around 12 vdc and minimal current now.