Enter the current and (internal) resistance of the battery into the calculator to estimate the power dissipated as heat (heat generation rate).
Battery Heat Generation (Ohmic Heating Power) Formula
The following formula is used to calculate the power dissipated as heat inside a battery due to internal resistance (also called the heat generation rate).
P = I^2 * R
Variables:
- P is the power dissipated as heat in watts (W)
- I is the current in amperes (A)
- R is the (internal) resistance in ohms (Ω)
To calculate the power dissipated as heat, square the current and multiply it by the resistance. This will give you the heat generation rate in watts. If you need total heat energy over a time t, use Q = P·t = I²·R·t (joules when t is in seconds).
What is Battery Heat Generation?
Battery heat generation refers to heat produced by a battery during operation. A common contributor is ohmic (I²R) heating from the battery’s internal resistance, which converts electrical energy into thermal energy when current flows. Understanding and managing battery heat generation is crucial for maintaining efficiency, safety, and longevity. Excessive heat can lead to battery degradation, reduced performance, and in extreme cases, safety hazards such as thermal runaway.
How to Calculate Battery Heat Generation?
The following steps outline how to calculate the Battery Heat Generation.
- First, determine the current flowing through the battery (I).
- Next, determine the internal resistance of the battery (R).
- Finally, calculate the power dissipated as heat using the formula P = I² * R.
- After inserting the values and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
Current (I) = 2 A
Resistance (R) = 0.5 Ω
Power dissipated as heat (P) = I²·R = 2²·0.5 = 2 W