I was looking for cell balancing time and I saw the following formula from here.
But I didn't figure out what's the unit of ocv slope. Is it a factor without unit or degree ...?
But I didn't figure out what's the unit of ocv slope. Is it a factor without unit or degree ...?
CHARGE WITH CB: in this state the cell balancing (CB) function will be activated. This function will calculate the estimated cell balance minutes per cell, which is based on the cell voltages, the difference compared to the lowest cell voltage, the balance resistor and the ocv-slope. The formula to calculate this estimated balance time is:
Code:
Estimated balance minutes = (Vcell - Vcell_min ) * Rbal / (Vcell * ocvslope)
Other than this calculated time, the BMS will check if the voltage of a cell that is being balanced, has reached the desired voltage as well. When the voltage of one of the cells reaches the cell overvoltage level or the charging current is less than the charge complete current, it will go to the RELAXATION state. The LED will stay blue and will blink if cell balancing is active.
Balancing is finished if all the calculated cell balance minutes are expired or it has reached the lowest cell voltage.