I have an Hitec X4 and I can charge 4 battery packs at once, or like guver said, I can set the first one, then later a second one, a third and a fourth all at different times. They will get charged the same. It will do 1S to 6S packs and balancing ports built into the charger.
[link]http://www.hitecrcd.com/products/chargers-setup-equipment/index.html[/link]
Rafael