I know an NiMH charger can also charge NiCad cells, but can a Ni-Cad charger also charge NiMH cells. Specifically, I am thinking of the Ni-Cad battery pack of a Dremel tool. It is rated 7.2v, and there are four cells wired to provide 3.6v and 7.2v for two speed operation. I would rather not replace the existing cells with more Ni-Cad, but with either NiMH or a LiPo battery pack. If worse comes to worst, I will just wire in an external jack and make up an external Li-Ion pack with a medium length cord.