Model of the Internal Resistance of the Starter Battery

On-board real-time monitoring of the technical condition of the starter battery is possible if a quantitative change in its parameters is measured during operation. The most informative parameter considering the change in both the terminal voltage and the discharge current is the battery’s internal resistance. To determine the battery’s internal resistance, the locked-gear starter motor loading mode was used. The impact of the electrolyte temperature, operating time, and the states of charge and health on the battery’s internal resistance has been experimentally determined. A mathematical model of the battery’s internal resistance is proposed, considering the change in the operating factors. Practical use of this model will allow onboard determining the technical condition of the battery.

I. Introduction

Most modern automotive systems cannot operate without electric power, the sources of which can be classified according to the following criteria (Fig. 1): by purpose (energy generation or storage) and the principle of operation (what type of energy is converted into electric power).