When two dissimilar metals are separated by an electrolyte a voltage potential is produced. This is how batteries work. We learned this somewhere around grades 4 through 6, we made batteries with lemons and potatoes. An 11 year old boy named Derek did well in science fairs with a well organized experiment testing different configurations of galvanic cells. His 14 year old sister helps him stay organized. The Effect of Metal Type on the Voltage of a Galvanic Cell Enter dutchsinse... This is just sad... and the comments are worse.