How do you calculate the internal resistance of a battery?
A real-life battery can be described as an ideal voltage source with an internal resistance.
If you measure the voltage of a battery with a Volt-meter, which has a very high resistance, you'll get the raw voltage.
If you add a smaller resistance between the poles of the battery, you will see that Ohm's law is not followed, but the amperage is lower than expected.
Measuring the current with a
In reality we measure
Therefore the total resistance
So the internal resistance of the battery in this case:
You can also work with the voltage loss on the poles of your battery. I'll leave that to you.