Battery testing

When we think of battery testing, we always immediately think of safety and quality. We all know the picture of the burnt-out Tesla. Or the story of the new Samsung Galaxy Note 7 phone that could spontaneously catch fire due to a construction fault. How can we avoid such situations as much as possible and minimise the consequences?

And then let’s start with the last one. Provide a safe testing environment. Think of special fire extinguishers, special fireproof cabinets and, for example, climate chambers with special facilities.

We can divide battery testing into three specific sections:

-Testing a battery cell
-Testing a battery module
-Testing a battery pack

The basis for a safe battery is laid when battery cells are tested. In Europe, this generally involves performing an incoming inspection on battery cells imported from the Far East.

By performing an insulation test, we can determine whether the separation of the poles by means of the dielectric is not contaminated. We also check the leakage current and that no partial discharge or arcing is taking place. We then determine the cell’s internal impedance and capacitance at different temperatures and charging voltages. For detailed information on how we perform these tests, please refer to the page testing a battery cell.

The tested battery cells are then incorporated back into a battery module. And there the series of tests actually starts all over again. First to see if the cells are properly interconnected. Then a test to check that no bad cells are included in the module and that the module meets the set specifications. In addition, it is also possible to test the battery management system for proper functioning.

For a detailed explanation of the various module tests, please refer to ‘Testing a battery module’.

It is then possible to link a large number of modules to form a battery pack. We obviously see this in somewhat higher power applications such as electric cars, buses, trucks and nowadays even electric boats.

And again, the testing actually starts from scratch.

– What is the capacity of the battery pack?
– And how much capacity do I have when the temperature drops to -10 degrees Celsius?
– Or plus 40 degrees Celsius?
– What if we start charging the battery dynamically?
– What if we are also going to recharge the battery with short (braking) pulses?

How far can we discharge the battery without suffering any damage in terms of battery life?

Again, we would like to refer you to battery pack testing to see what options are available for comprehensive pack testing. For total testing solutions, please refer to the page on automatic battery testing test software and test systems.

We also recommend the complete presentation we made for the benefit of the Energy Storage Event 2020, ‘Testing Li-ion batteries’.

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