Battery Testing with the Calculated Discharge Curve Method-3D Mathematical Model

Abstract

The calculated discharge curve method is based on thermodynamically reversible work: The product of the open-circuit voltage, initial current, and time, i.e., the sum of useful energy and energy losses. A calculated discharge curve is based on the constant step change of the battery voltage in correspondence with a cardinal number set. The essential solution is the transformation of the discharge data voltage vs. time into time vs. voltage using basic equations (three-point operators: power of internal resistance and time), which are valid for all battery electrochemical systems, battery designs and discharge conditions. The mono and multi-cell battery operating conditions consist of the following: 1) The four discharge modes by constant loads: resistor, current, voltage, and power; 2) Two load regimes: Self-driving and device-driving (galvanostat, potentiostat) or battery connection (serial, parallel, combine); and 3) Continual and intermittent discharge. The battery average cell and cell/battery average characteristics, regarding time and capacities, are introduced as the new battery characteristics.