Vehicle power battery SOC value reporting method and device and battery management system

The invention provides a vehicle power battery SOC value reporting method and device and a battery management system. The method comprises the steps that firstly, an SOC value B of a power battery at the current moment is estimated; secondly, the difference value n% between the SOC value B estimated at the current moment and an SOC value A reported to a vehicle controller at the previous moment is calculated; thirdly, whether the absolute value of the difference value n% is larger than a preset jumping limiting value x% or not is judged, wherein the preset jumping limiting value x% is larger than zero, the SOC value B at the current moment is directly reported to the vehicle controller if the absolute value of the difference value n% is smaller than or equal to the preset jumping limiting value x%, and the next step is executed if the absolute value of the difference value n% is larger than the preset jumping limiting value x%; fourthly, whether the difference value n% is larger than zero or not is judged, if the difference value n% is larger than zero, the SOC value at the current moment is reported to the vehicle controller with B+x%, and if the difference value n% is smaller than or equal to zero, the SOC value at the current moment is reported to the vehicle controller with B-x%.