My dremels battery had finally had enough. It wouldn't hold a charge for more than a few minutes. Most of what I do requires a dremel, one that works. So, I did what any hacker would do. I looked around for alternative power methods and found a drill that I no longer use. This drill had a few 1.2 volt nicd cells that were all ran in series to create 12 volts. I took the battery pack apart and removed all the cells. Then made my own battery pack using 8 of the cells. I ran two cells in parallel then in series with another two cells in series. I did this twice. So there are 2 sets of batteries at 2.4 volts each. With the flick of a switch I can pick either one pack at 2.4 volts or both packs at 4.8 volts for high speed. I covered the entire build in the Youtube video below.