The fluxgate principle has an absolute technical advantage in the field of high-precision measurement. The continuous oscillation of the excitation magnetic field is equivalent to the degaussing magnetic field, thereby minimizing the hysteresis. Item 4.2.4 of the national standard QCT 897-2011 stipulates that the SOC estimation accuracy requirement is not greater than 10%. In order to ensure this accuracy, the charging and discharging monitoring accuracy should be better than 1%. In order to ensure high- precision SOC under both large current and low current conditions, the full-scale accuracy of the sensor should be further improved by 0.3%. AHBC-CANB power sensor meets the accuracy requirements, and has smaller hysteresis and smaller zero offset.