Simulation of the discharge curve by short-time discharge based on the power of internal resistance

Abstract

The actual discharge curve of the power source depends upon the voltage, the capacity, the load, and upon the condition of the power source at the time of use. A reliable power supply from the chemical power source can be achieved by simulation of its discharge curve. The methodology of simulation of discharge curves by set: time t (s) versus discharge voltage, U d (V), from a short-time discharge (<1% of total discharge time) through the constant load at the constant temperature have been developed. The two basic equations were defined: (i) discharge current, U d/ R l (A), U d n /R 1 = a nt n bn and, (ii) potential drop, P d (V), by introducing estimating voltage U (V) instead of the open-circuit of potential, U o (V): U − U d n = c nt n d n . From these equations, the equation for the power of internal resistance P i (V A) can be derived: [ U d n ( U − U d n )]/ R 1 = a nc nt n ( bn + dn) . The equation for the power of internal resistance was used to simulate the discharge curve. Alkaline manganese cells LR 20-VARTA, loads: 10 Ω and 3.33 Ω, were used for the demonstration of method. The mathematical calculations were conducted on an IBM personal computer using Symphony software. The method was developed to test the quality of the produced cells and batteries, reliable exploitation of all systems of chemical power sources, and optimization of the battery charging. The method is a fast, nondischarging, nondestructive and repetitive technique.