3 ms·
You can get a 12" square sheet of zinc for under US$10 and make a couple dozen anodes from it. Copper cathodes will be a bit more expensive, but the total elec
by mbrubeck 12y ago
You can get a 12" square sheet of zinc for under US$10 and make a couple dozen anodes from it.
Copper cathodes will be a bit more expensive, but the total electrode cost should still be only a few dollars for several months worth of light.
- sbierwagen 12y agoThe electrodes are going to have to be pretty thick, chunky grids to last six months, not thin sheets, and retail price is typically a 100% markup over BOM cost.
- Elrac 12y agoOr the cathode is carbon. Then (IIRC) it wouldn't wear out or need replacing.
- sbierwagen 12y agohttp://en.wikipedia.org/wiki/Galvanic_cell http://en.wikipedia.org/wiki/Galvanic_cell The has energy come from somewhere. In an electrochemical battery, it comes from chemical reactions with the electrodes, which consume the electrode material.
- VLM 12y agoIts basically one of these: http://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery http://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery The carbon rod never corrodes. If you want to be picky its more of a zinc-manganese battery with a carbon rod as a non-corrosive wire but whatever.
- Elrac 12y agoAs VLM explains a bit better, I was talking about only one of the two electrodes. The other one, the anode, would of course be made from zinc (or some other metal) and end up breaking down to provide that energy. I was just explaining why the battery might not need two electrodes breaking down.