It’s to adjust charging voltage based on 2V/cell when battery temperature is changing between 0~50°C. All charging settings are based on 25°C. If setting battery temperature compensation as 5mV, charging voltage will be reduced by the following formula.
(T-25) * (Battery voltage with serial connection / 2 ) * 5mV
For example, 3-phase inverter with 48VDC under 30°C environment.
(30 – 25) * (48VDC / 2 V/cell ) * 5 mV = 600mV. Then, when battery temperature is higher 5°C, charging voltage will be reduced 600mV. Vice versa.