A method of monitoring an electrical storage system. The method includes providing an electrical storage element defining a total storage capacity and having a state of charge cooperatively defining a total stored charge of the electrical storage element, determining a total stored charge value representative of the total stored charge of the electrical storage element, varying the total stored charge by charging the electrical storage element from the power source via an electrical charge or discharging the electrical storage element to the load via an electrical discharge, and updating the total stored charge value after varying the total stored charge.