The invention discloses a
cascade utilization
screening method of waste power batteries. The method comprises the following steps of: (1) charging a waste
power battery pack, so that the
state of charge (SOC) of the waste
power battery pack is 15 to 80 percent; (2) detecting the open-circuit
voltage and
internal resistance of each single battery; (3) connecting the single waste power batteries in parallel until the open-circuit voltages of the single waste power batteries are basically the same, comparing the open-circuit voltages of the connected batteries with the open-circuit
voltage of each single battery which is not connected in parallel, recording a
voltage fluctuation situation, putting the waste single batteries and standard single batteries at the temperature of 30 to 55 DEG C for 3 to 7 days or at
room temperature for 10 to 30 days, and detecting the open-circuit voltages and the
internal resistance of the waste single batteries and the standard single batteries; and (4) comparing the single waste power batteries in terms of appearance, open-circuit voltage,
internal resistance,
voltage fluctuation and health, classifying the single waste power batteries, and matching battery packs in the same class with an
energy storage power grid. The method is simple, the
utilization rate of power batteries is improved, the usage cost of
energy storage batteries is reduced, and the large-scale screening, classification and
cascade utilization of waste power batteries can be realized.