Used Battery Sorting by Resistance Thresholds

The patent segments used secondary batteries into three distinct groups based on their resistance characteristics: initial-stage high-resistance batteries, middle-stage low-resistance batteries, and ending-stage high-resistance batteries. This segmentation allows batteries with similar characteristics to be grouped together, ensuring uniform performance within each group while maximizing the utilization of all usable batteries across the three stages.

The patent uses battery resistance as a key parameter to classify and sort used secondary batteries. By measuring and comparing resistance values against predefined thresholds, the system identifies which stage each battery is in and assigns it to the appropriate group. This parameter-based classification ensures that batteries are rebuilt in packs with uniform characteristics, maintaining reliability while increasing the quantity of usable batteries.

The patent divides used batteries into three separate segments based on their resistance characteristics corresponding to different usage stages. By keeping batteries from different stages separated into distinct groups, the system prevents mixing batteries with vastly different characteristics, thereby avoiding harmful effects like overvoltage, overcharge, and early rundown that would occur if heterogeneous batteries were combined in the same pack.

The patent applies local quality by assigning batteries to specific groups based on their individual resistance characteristics and usage stage. Each group (initial-stage, middle-stage, ending-stage) has uniform local qualities in terms of resistance and deterioration level, ensuring that batteries within each group behave consistently during charging and discharging, thus preventing harmful effects.