Cell characterization: a guarantee of quality

1) Definition

To characterize cells is to carry out a set of tests whose results will be analyzed jointly in order to highlight the individual performances under different conditions.

The characterization is easily comparable to a product identity card.

2) Method

Our test procedure has been built empirically and has been proven on a considerable number of cells. Our engineers have defined strict criteria which must be met by the cells offered in the SIG Energy Technology catalog. This is how we can guarantee you a product range of the highest quality.

There are 5 different types of test:

• Capacity and voltage at different c-rates
• Open circuit voltage at different states of charge (SOC-OCV)
• Internal resistance at different load states (DCIR)
• Impedance at 1kHz (ACIR)
• Cycling ageing

Cycling ageing: This test gives real results as opposed to the simulation where we obtain virtual results. We check the manufacturer's data and the number of cycles for each cell. This is how we observe an under or overestimated life span. During this test period, we regularly carry out an assessment of the cell's condition in order to follow the evolution of its internal resistance. The goal is to know perfectly the cell, its performances and its behavior during its life. This test allows the customer to anticipate the lifetime of his finished product, to configure the BMS in the best possible way and to propose an adapted warranty. It requires multiple tests and a lot of evaluation time. We are talking about tests that can last more than a year with relevant results but impossible for the customer to perform for each application.

3) Customer feedback

SIG Energy Technology is a reference company on the European market of Lithium-ion cells. Our high-performance products are the hallmark of our brand image among professionals in the automotive, stationary storage and industrial sectors. Thanks to our rigorous testing and the quality of our products, SIG Energy Technology's return rate is almost zero.