Advanced battery monitoring and charging techniques for UPS

Mission critical applications for battery systems need reliable and accurate measurement of battery capacity, particularly with uninterruptible power supplies (UPS). This paper explores the unique, patented approach used at the Square D Company to provide battery capacity monitoring with high accuracy in the standard metering package of their newest UPS products. Their challenge was not simply to predict battery capacity for a given static load, but to do so with reasonable accuracy for dynamic loads and different battery temperatures. The result is a unique approach that models internal battery resistance to predict capacity and life expectancy.<>