I do also. They work a bit better for four cell packs than 6 cell packs. Unless you get up to around 350-400 watt power supplies. The input voltage drops down when you get towards the end of a 6 cell charge cycle. At least for me. But you can't beat it for the price. I like making them out of the older ones, not the newer style ones. The newer ones are a pain.
To get the newer ones to run, you need to jumper the I believe it's the oragne and a ground wire in the big 20 row connector. I think those are the two wires, its been awhile. Without doing that it won't work. And then you can't just cut all the wires off at once and put those two together. Some of them need to go together and stay together. It's really a pain in the butt to figure out. Really need to cut one wire at a time and try it out. The older style supplies are MUCH more simple.