US Patent 9207285 Automatic determination of multi-frequency baselines for battery testing

Baseline values for battery testing are automatically determined for individual batteries, battery cells, or networks of batteries. Impedance information is obtained from individual batteries and adjusted for operating conditions at a site of use (e.g., temperature, age, connection topology and user-entered information). Population-referenced baselines are automatically calculated from the group of individual-referenced baselines. All baselines can be continually updated and improved. The state of charge and state of health characteristics of batteries in the network can be automatically determined by comparison of measured impedance, and other values, to the baselines.