Energy storage system of a vehicle

A computer-implemented method, comprising:

• determining, by a processing circuitry of a computer system, SOC operating windows of a battery pack configured to power an electric traction machine of an electric vehicle, according to predefined limited state of charge (SOC) limits extending from a lower limited SOC limit to an upper limited SOC limit, and predefined extended SOC limits extending from a lower extended SOC limit to an upper extended SOC limit, the upper extended SOC limit being higher than the upper limited SOC limit;
• determining, by the processing circuitry, an anticipated operating mode of the vehicle as a predefined cold start operating mode;
• in response of determining the anticipated cold start operating mode, charging, by the processing circuitry, the battery pack in accordance with the extended SOC limits to at least above a level corresponding to that of the upper limited SOC limit;
• and
• during subsequent operation of the vehicle by powering the electric traction machine by the battery pack, and in response of that the SOC of the battery pack is within the extended SOC limits and above a level corresponding to that of the upper limited SOC limit, powering, by the processing circuitry, an electric heater arranged in a heat storage tank comprising a heating fluid by a regenerative braking system of the vehicle in order to heat the heating fluid of the heat storage tank.