1. The problem statement, all variables and given/known data Does a flashlight battery have internal resistance? Explain. 2. Relevant equations V = ε - Ir 3. The attempt at a solution Yes, they do have internal resistance. This results in the open circuit ε being different than the voltage measured across the terminals if a current is drawn from the source. I'm not sure why, though. I'm also not sure if the question is asking why they have internal resistance or if its just asking what the implications of this internal resistance are.