Method and device for estimating state of charge of battery, and equipment

The invention provides a method for estimating the state of charge of a battery. The method comprises the following steps: searching a relation mapping table according to the temperature of the battery at the current moment and the state of charge value of the battery at a first moment, obtaining the internal resistance value of the battery at the current moment, and determining the open-circuit voltage of the battery at the current moment according to the voltage at the two ends of the battery at the current moment, the internal resistance value of the battery at the current moment and the charging/discharging current at the current moment; determining a first state-of-charge value of the battery at the current moment according to the open-circuit voltage of the battery at the current moment and a preset corresponding relation between the open-circuit voltage and the state-of-charge; and according to the first charge state value of the battery at the current moment, the change capacity of the battery from th