interchangeable battery chargers
Is the battery charger for a 30D capable of charging the battery for the 5d Mk II?
No. There is a dedicated charger for each type of battery. Some models use the same battery and charger, for example the 5DII, 5DIII, 7D, and 60D are the same.
Pearstone chargers would be closer to doing this. They use an interchangeable plate system on some of their models to allow using one charger for different battery types. Much less money than buying separate Canon replacement chargers. Of course, their dedicated model chargers are even less and most allow 110VAC as well as 12VDC and even come with both plugs.