Introduction

Procedure for detecting the state of health / degradation of the elementary cells that constitute a battery pack. It consists of a charge and discharge test and the calculation of some cell degradation indicators.

Technical features

A charge and discharge test of the battery pack is performed and on the basis of the data provided by the measurement system of the pack itself, three indicators of capacity and impedance of the individual subgroups of cells that compose it are calculated. With these data the value of a degradation function is calculated which quantifies the health conditions of each subgroup of cells and provides information on their withdrawal from the application considered. Unlike the methods used to date, this procedure is inexpensive, does not require additional costs related to instrumentation, is reliable in terms of numerical calculation, and is fast.

Possible Applications

• Diagnosis of stationary storage systems;
• Diagnosis of automobile batteries;
• Battery ageing studies on specific chemistries or cycles.

Advantages

• It does not require dedicated tools;
• It uses integral numerical calculations, it is very precise;
• The numerical procedure can be implemented on any PC;
• The test is standard for storage systems.