Good job. It might help to use paper towel instead of card board. You could check for maximum current. Put your meter in the 10 amp range and see what you get.
Excellent school project ! .... but for a super dooper battery for your projects , just VERY CAREFULLY remove the battery from any disposable vape ( found on most sidewalks ! ) , you MUST use a soldering iron .... and remember these deliver HUGE currents , so NEVER short them out , and ... NEVER recharge above 4.2 volts ( so , do NOT connect direct to 5 Volt USB outlets ! ) , an added bonus is , that they NEVER leak like ( OMG ! ) alkaline cells .. ( tried - n - tested ) .. DAVE™🛑
You must use solid copper pennies, and this is known as a voltaic pile, there is supposed to be a soaking wet with salt water felt spacer between each one of the coins, solid copper pennies, nickels, felt washers/spacers soaked in electrolyte, try that
Should not need to be solid copper penny. Newer US pennies are zinc on the inside but copper outside. For this basic proof of concept science experiment, the battery does not have time to eat through the outer copper. So even if it was solid copper, the core would not be touched.
FAKE I JUST BUILT ONE AND IT DOESN'T WORK. You laugh I have proof. I connected my multimeter to it and it says Zero Volts. Oops, sorry about that it's a brand new multimeter and in the instructions it says insert 9 Volt Battery into slot for multimeter. God, maybe I smoked too much pot today. Honey, do I look alright ?... 🤪
