potato battery

In science electivee did rotation about solar car a magnet car, Brainbox, Potato battery and a lemon battery Our first one we did was the brain box but second one we did was the potato battery.In potato battery we did seven potatoes for a little light with copper wire pennies and nails. We did like three tries the first one was fi the second one was a fail and the third one we flipped them all over like we put the nails and pennies the wrong way and then it did work.