Sure you could take $2.50 and just buy some batteries, but how much fun would that be?
Step 1: Mix cider vinegar & salt In a bowl, mix the cider vinegar and some salt.
Step 2: Cut out blotter paper Cut out ten quarter-sized pieces of blotter paper.
Step 3: Tear aluminum foil Tear off ten quarter-sized pieces of aluminum foil.
Step 4: Soak blotted paper Soak the blotter paper in the vinegar/salt mixture for a few minutes.
Step 5: Build the battery Time to build the battery. Start with a piece of foil, then a piece of blotter paper, then a quarter. Keep stacking in the same pattern: foil, paper, quarter… foil, paper, quarter… Until you’re out of quarters.
TIP: Make sure the foil is only making contact where it’s supposed to. If it’s touching more than one quarter, or another piece of foil, your battery may not work.
Step 6: Let battery charge Let the battery charge for about 15 minutes.
Step 7: Touch LED's leads Touch the LED’s negative lead to the bottom layer of foil, and the positive lead to the quarter on the top and presto – you have light.
FACT: This method of generating electricity was discovered in 1800 by Alessandro Volta. His voltaic pile was the first wet cell battery to produce a reliable steady current of electricity.