The MH-777 universal charger will charge both NiCad and NiMH celled batteries. It has a discharge function and can be used to condition older NiCad cells. It has a set of movable charging pins that you can set to fit the 6000 series battery packs and many other types of batteries, plus a connector that will allow you to connect charging cords - one for 6000 batteries made by LA Flex for 6000 packs included. This charger also has a magnetic thermistor that you can place over the batteries to monitor their temperature to make sure they don't overheat. Not recommended for Lithium cells.
This has been tested and is working. I understand these are really useful for ham radio equipment and model railroad and other hobby equipment. They will work with the 6000 packs, but are a bit fiddly for that.