Suppose I have a 100 mAh battery at 20V. I connect a 1000 kohm resistor across it. How much heat will be generated and how can I find the temperature rise in the resistor? As the battery operates I think that the current flow will reduce over time but am not sure about the voltage for a real battery. Perhaps I am not giving sufficient information here, I am sorry for that.
I just wish to know, what information is needed to make such calculation? Have you ever done it? In the ideal case (taking only the most significant factors into consideration) what factors are considered to make an estimate of the heat dissipation and temperature rise and why would the real heat dissipation and temperature in the actual practical experiment be different?
I know this question looks hard, but I will be very happy if I can finally have this mystery resolved.