What battery model is used when Otii emulates a battery?

Otii models the battery with an Open Circuit Voltage (OCV) and internal resistance of the battery (Ri). OCV and Ri is measured for the complete capacity of the battery and is stored in a battery profile .json file.

The resolution of the Ri is dependent on the difference between the high-current and the low-current during the profiling so a low resistance battery, for example Li-Ion, needs a bigger difference between high current and low current, than when profiling a high resistance battery, for example a coin-cell.