Method for measuring state of charge of battery

A method for determining the battery state of charge SOC adopts corrected ampere hour integration method (Figure) to determine the battery state of charge SOC value at the time of t; the measurement method of the correction function fai (t) comprises the following steps: an SOC theoretical value calculated formula is adopted to calculate the battery state of charge SOC theoretical values SOC(theoretical) at a plurality of times; and the battery state of charge SOC actual values SOC(actual) at the plurality of times are measured; through the least square method, the correction function fai (t)standing for the relation between the difference value between the SOC(theoretical) and the SOC(actual), and the plurality of times; wherein, the SOC theoretical value calculation formula in step (a)adopts the basic ampere hour integration method (see the above formula); and x stands for one of the plurality of times. The application of the method can obtain accurate correction functions so as to achieve more precise battery state of charge SOC values to give full play to the battery performance and ensure the safety of the complete vehicle systems.