Re: [PIC]: Potato Powered PIC? by Douglas Wood .

I recently have been experimenting with fruit batteries. My daughter's boyfriend came to me needing help with a school science project where he needed to build a car that was propelled with a "chemical reaction". His first thought was to use vinegar and baking soda to drive a pneumatic motor, which weighed about five pounds! Unfortunately, by the time he would have built a car big enough to support all of the equipment needed to generate enough gas to drive the car, the thing would have needed several pounds of soda and several gallons of vinegar!!! I suggested driving a hobby DC motor/gear box combination with a fruit battery. Slipping all of the interceding research, I found that plastic soda bottle caps arranged in a honeycomb pattern (for density) filled with lemon juice work the best. Each battery cell was filled roughly half with juice and I used common zinc galvanized nails and copper mesh for the electrodes (The copper mesh provided a greater surface area for the chemical reaction to occur and produced about three times the current output when compared to a copper nail). Lemons work the best of all fruits (apples, oranges, lemon, limes, etc.) that I tried. Other foods I tried included [chilli] peppers and potatoes (potatoes are rechargeable!). The general rule of thumb is that a whole lemon will produce approximately 1 mA at 1 Vdc. I used the bottle caps to reduce the weight of the battery. Hope that helps... Douglas Wood Software Engineer dbwood@spam@KILLspamkc.rr.com Home of the EPICIS Development System for the PIC and SX http://epicis.piclist.com {Original Message removed}