The first battery that we did gave us around 0.7 V, which is not that different to the number that we saw when doing the research about the battery, but it was not enough to power the motor, so we had to try different methods.
In the second battery, we decided to try and replicate a voltaic pile with our own components and that gave around 1.2 V, which still was not enough to power the motor.
In the third battery, although we did the same voltaic pile, we used vinegar as an electrolyte rather than salt water and that gave us around 2.2 V, which, in theory, would be enough to power the motor, but when we tried to connect the battery to the motor and there wasn’t any movement.
We even tried a fourth battery, which was essentially the third battery but with more stacks, and it gave us a total of 3.2 V, but there was still no movement. We quickly found out that this was due to the internal resistance of the battery, which we didn’t know was a problem.
The Internal resistance is the resistance that is created by the electrolyte within the cell between the two electrodes. In our case, the electrodes were the copper and the zinc, and when we tried to connect the battery to the multimeter just by itself, it gave us 3.2 V as said before, and this number gave us the electromotive force of the battery. On a closed circuit, where the battery was connected to the motor, we measured 0.05 V on the multimeter, which gave us the voltage of the circuit. We also took a look at the values of electric current in the circuit, and it turned out to give us 0,0015 A, which is a very low number. After doing the math, it turned out that the internal resistance of the materials was around 2100 Ohms per cell, which is a lot!
We have seen articles online, that suggest that we can decrease the internal resistance by:
