The saga continues. Bigger top heat sink, plans for the final unit, better output, direct charging. Mostly made from junk, I have come to the conclusion that success in this project is a cost relationship. You truly need to scrounge some great heat sinks (unless you have a natural source of cold/heat directly together, like a woodstove outdoor smokestack. In the new setup I had about 2.54V (open circuit) and I measured 60 mA of (closed circuit) charging current when the battery was nearly topped up, at 1.33V, and climbing. In the final version, given my space available, I will use 6 peltier modules for a voltage of about 3.5V (or better) and working current of better than 60 mA (about 110 mA open circuit). Possibly I will hit the point I can charge a 3.6V li-ion bat, that way you can just throw it in and forget it, as they are 4000 mAH, plus, once charged, they can provide HUGE light, one alone.
