> > > The tools are fine, the problem is you can't string 12-15 cells together > and then charge them as fast as possible without something going > backwards (like the voltage on one of the cells!). None of the chargers > even offer to charge slowly, say overnight. I agree. When you study the problem, it becomes apparent that beyond six cells, you can't see what's happening with enough certanity. It would be interesting to see a design that used six beefier cells, and a SEPIC converter, which would also double as the speed control. -- > Feel the power of the dark side! Atmel AVR -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist