BigPatents India

A process of determining State of Charge (SOC) and State of Health (SOH) of a battery under on-load conditions comprises the steps of drawing the temperature-internal resistance (temp-IR) characteristics of the battery by measuring the battery temperature and the internal resistance at three to four operating temperatures with different ages of battery at various levels of discharge conditions; training an artificial neural network (ANN) with measured inputs, namely, terminal voltage(2), current drawn from the battery(4) and internal resistance(1), and, optionally, with other inputs, duly measured, and selected from one or more of, battery temperature(3) and consumption time (5), for the purpose of obtaining the output Specific Gravity(SG) of the battery, said battery temperature(3) input to the ANN being extracted by least square fit of said (temp-IR) characteristics; determining the State of Charge (SOC) of the battery by deploying fuzzy rule base using the battery temperature(3), as extracted, and the Specific Gravity(SG); and determining the State of Health (SOH) of the battery in terms of percentage of remaining life of the battery, based on the measured inputs such as, current drawn from the battery(4), consumption time(5), total consumption time(6) and slope of said Specific Gravity(SG) to total consumption time (6), and using a mathematical model. (FIG.1).