OK if we have a circuit with a battery of emf e and internal resistance r and external resistance R. We are given that the current in the circuit is I. What is the thermal power generated in the battery and the power developed in it by the electrical forces. OK straightforward "formula" question you say. I know that thermal energy is produced due to resistances(only?).IN this case it would be r. So thermal power = I^2r. Now my second doubt(I hope you got the first question);power developed by the electric force.I "think" that inside a battery the electric force(due to chemical action) generates power = Ie. But the answer is P = -I(e-Ir). Also shoudnt the power be +ve as the battery is actually discharging?