How to Power a Stopwatch with a Homemade Battery

Adam Kemp: I am Adam Kemp and today we are learning about how to make a battery. In this clip we are going to power a stopwatch with two of our homemade batteries. In this case, we are going to use two of the film canister batteries that we developed earlier. We are using these batteries because of their high amount of voltage produced and the high amount of current. We can start by measuring the amount of voltage being produced by them, I am using a multimeter and in the first battery, we are getting about 0.9 volts and in the second battery, we are getting about 0.92 volts. To start let's try powering our stopwatch with just one of our homemade batteries. If you flip stopwatch over, you'll notice this one is powered normally by button cell type batteries. Button cell batteries usually have a low amount of voltage produced as well as the low amount of current, making this an optimal device to try to power with the homemade batteries.

If we look at the inside of our stopwatch, you will notice that it's got two pieces of metal that I have exposed. The one on the bottom is going to be our cathode and the one on the side is going to be our anode. We can go ahead and take two of our leads and connect them to these pieces of metal. If you flip the stopwatch over -- now that you have attached the leads to the end of the cathode in the battery compartment of the stopwatch, you can go ahead and attach them to the battery that you've created.

Now, don't be fooled if this doesn't turn on immediately; it might take a second for your electronic component to turn on and just see the stopwatch has turned on and it's fully functioning, just as it were if it had some normal button cell battery. I hope you have enjoyed my demonstration about how to make a battery; thanks for watching.