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An unbalanced battery affects its performance. Of course the battery system is operational
but the autonomy is not at full performance during the first days. For example, a difference of
100mV between minimum and maximum cells’ voltages minimizes by 15% its capacity.
Battery performance is at its maximum when the balancing is done at a full charge (100%
SOC).
The balancing duration is depending on the voltage difference between the cells: balancing
efficiency is 25mV per day for VL45E, in average (depending on cell voltage). For example: if a
battery is stored during one year, the battery balancing can take up to 20 days.
The balancing can be considered as finished when the voltage difference is lower than 30mV.
Perform a full charge for 24h every 3 month keeps modules balanced each other and
avoid a long time of balancing.
Before assembling modules after a long period of storage, it is advised to charge modules
separately at the same voltage level before battery assembling in order to minimize the
inter-module cells equalizing.