I would totally expect a super capacitor or something for this sort of thing. What are the effects of loading 12V across a single Li-ion cell? Or am I missing something about Ohm's law and that 12V will actually drop to a much lower voltage due to the near 0-Ohm ESR of the battery and the effective charging input power to the battery is within a safe range? --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .