Measuring Internal Resistance of Batteries
Contributors: Shawn HymelFavorited Favorite 7
Calculate the Internal Resistance
Using the voltage readings from the "10k Ω Load" and the "No Load" (open circuit), calculate the internal resistance of the lemon battery.
Hint: Refer to the Internal Resistance section to see how to calculate this value.
- Does the internal resistance of the lemon battery seem high or low?
- What is the maximum current your lemon battery can provide? (Hint: imagine connecting a wire between the terminals. How much current would flow through the circuit?)
- Re-calculate the internal resistance using the "330 Ω Load" and "No Load" values. Does it match your first calculation? If not, what do you think would cause the difference?
- Perform the whole experiment again using a consumer-grade battery, such as a AA alkaline cell. What is the maximum current a AA can provide?