|MadSci Network: Biochemistry|
The potato battery experiments use copper and zinc electrodes.
The metals from the electrodes can potentially leach into the potatoes.
Copper and zinc are trace nutrients in small amounts, but toxic in large amounts.
Although you say that you will only use the potatoes for a few hours, I donít know of any data on exactly how much zinc and or copper would be deposited in the potatoes in that amount of time (although that would be an interesting experiment in itself!)
Without any data on the leaching rate, Iím afraid my recommendation is that you do not eat the potatoes to avoid any toxic reactions from the zinc or the copper.
Try the links in the MadSci Library for more information on Biochemistry.