Why are battery models required?

The electrical behaviour of a battery is governed by complex electrochemical processes occurring inside the cell. While quantities such as voltage, current, and temperature can be measured directly, important internal states, including State of Charge (SoC), internal polarization, and energy losses, cannot be observed directly.

Battery models provide a mathematical representation of these internal processes by relating measurable electrical signals to the underlying behaviour of the battery.

A battery model can be used to:

• Estimate internal battery states such as SoC.
• Predict terminal voltage under different operating conditions.
• Simulate battery behaviour before physical testing.
• Design and validate battery management algorithms.
• Improve the accuracy and robustness of battery state estimation.

The choice of battery model depends on the required level of accuracy, computational complexity, and application. Highly detailed models provide greater physical accuracy but require significant computational resources, whereas simplified models are more suitable for real-time implementation.

Several modelling approaches have therefore been developed, each balancing physical accuracy and computational efficiency in different ways.