Patent ID: 9515508
Filing Date: 2016-12-06
CPC Classification: H01M,H02J,Y02E

Claim Text:
1. A system comprising: detecting circuitry that detects cell voltages of a first plurality of battery cells of a battery pack; and first control circuitry, coupled to said detecting circuitry, that selectively operates in a state that is one of a normal state and a charging prohibition state based on a predetermined overcharge threshold, a predetermined overcharge-released threshold less than said predetermined overcharge threshold, and a balance threshold less than said predetermined overcharge-released threshold, wherein in said normal state, charging of said first plurality of battery cells is enabled and each of said cell voltages keeps increasing during the entire period of said normal state, said first control circuitry balances said first plurality of battery cells by decreasing a rate of voltage increase of a battery cell of said first plurality of battery cells if a voltage of said battery cell of said first plurality of battery cells is greater than said balance threshold, and said first control circuitry transitions from said normal state to said charging prohibition state if a first voltage of a first battery cell of said first plurality of battery cells exceeds said predetermined overcharge threshold, wherein in said charging prohibition state, charging of said first plurality of battery cells is disabled, and if a second battery cell of said first plurality of battery cells has a voltage greater than said balance threshold and a third battery cell of said first plurality of battery cells has a voltage less than said balance threshold, then said first control circuitry enables discharging of said first battery cell and said second battery cell, and wherein in said charging prohibition state, if said first voltage of said first battery cell falls to said predetermined overcharge-released threshold, then said first control circuitry transitions from said charging prohibition state to said normal state and enables charging of said first plurality of battery cells.