US 12,292,480 B2
Controller and method for detecting battery cell voltage
Yan Li, Wuhan (CN); Hui Liu, Wuhan (CN); and Guoxing Li, Sunnyvale, CA (US)
Assigned to O2Micro, Inc., Sunnyvale, CA (US)
Filed by O2Micro, Inc., Santa Clara, CA (US)
Filed on Jul. 6, 2021, as Appl. No. 17/368,637.
Claims priority of application No. 202011107626.4 (CN), filed on Oct. 16, 2020.
Prior Publication US 2022/0120819 A1, Apr. 21, 2022
Int. Cl. G01R 31/3835 (2019.01)
CPC G01R 31/3835 (2019.01) 26 Claims
OG exemplary drawing
 
1. A method for detecting voltages of a plurality of battery cells coupled in series in a battery pack by controlling a plurality of switching units and a switch, wherein each battery cell of said plurality of battery cells comprises an anode coupled to a respective converter of a plurality of converters through a respective switching unit of said plurality of switching units and comprises a cathode coupled to said respective converter through a respective path of a plurality of paths, wherein said switch is coupled between a compensation circuit and the respective path for a top battery cell that is at an end of said series of said plurality of battery cells, said method comprising:
performing a first plurality of operations in parallel in a first time period; and
performing a second plurality of operations in parallel in a second time period,
wherein said first plurality of operations comprises:
turning on the respective switching unit for said top battery cell to enable the anode of said top battery cell to provide a first operating current and a first sampling current that flow to ground through the respective switching unit for said top battery cell and the respective converter for said top battery cell;
enabling a first current to flow to said ground from the cathode of said top battery cell through the respective path for said top battery cell; and
detecting a voltage of said top battery cell by said respective converter for said top battery cell,
and wherein said second plurality of operations comprises:
turning on a first switching unit of said plurality of switching units to enable a second operating current and a second sampling current to flow through said first switching unit;
generating a balancing current by said compensation circuit according to said second operating current and said second sampling current; and
turning on said switch to allow said balancing current to flow from said compensation circuit through said cathode of said top battery cell to said anode of said top battery cell.