Intelligent battery management system and method

A battery management system for charging or discharging a connected battery, using calculated non-equilibrium potentials for one or more of the negative and positive electrodes of the battery and one or more electrode potential set points the battery management system comprising:

• a measurement module for determining for a connected battery one or more battery state parameters indicating the present state of the connected battery, the battery state parameters including one or more of the instantaneous battery potential, the battery current, and the battery temperature;
• a set points module for receiving an indication of electrode potential set points for the negative electrode potential and the positive electrode potential of the connected battery, the electrode potential set points including a maximum and a minimum electrode potential set point defining the range of electrode potential operating values for the negative electrode and positive electrode;
• a battery state estimator module for determining an instantaneous negative electrode potential and an instantaneous positive electrode potential for the connected battery based on a determined state of charge for the connected battery and an over potential fraction map, wherein the overpotential fraction map maps respective state-of-charge values for a reference battery to the corresponding fractions of the battery overpotential that are attributable to the negative and the positive electrodes;
• and
• a control module for controlling a charging/discharging current for the connected battery, or controlling a charging/discharging voltage for the connected battery based on the determined instantaneous negative electrode potential and the instantaneous positive electrode potential, such that the determined instantaneous negative electrode potential and the instantaneous positive electrode potential remain within a range of electrode potential operating values defined by the received indication of one or more electrode potential set points.

A computer implemented battery management diagnostic method using non-equilibrium potentials for one or more of the negative and positive electrodes determined for the battery, the battery management method comprising the steps of:

• determining for a connected battery one or more battery state parameters indicating the present state of the connected battery, the battery state parameters including at least the instantaneous cell potential and the state-of-charge of the connected battery;
• estimating for the connected battery, based upon the determined state-of-charge, one or more of the battery open-circuit potential and the open-circuit electrode potentials for the negative and/or positive electrodes;
• determining the overpotentials for the one or more of the positive and negative electrodes of the connected battery, based on the estimated open-circuit potential for the reference battery, by referring to a reference overpotential fraction representation that is available in memory and which maps the respective state-of-charge values for the reference battery to the corresponding fractions of the battery overpotential that are attributable to the negative and the positive electrodes;
• determining the non-equilibrium electrode potentials for the one or more of the negative and positive electrodes of the connected battery, based on the estimated open-circuit potential of the negative and/or positive electrodes of the reference battery, and the overpotentials for the respective negative and/or positive electrode;
• and
• determining one or more parameters indicative of battery health depending on the determined non-equilibrium potentials for the one or more of the negative and positive electrodes,
• wherein one or more of the determined negative and positive electrode potential is used as a state-of-available-power indicator for the connected battery.