How battery tests ensure safety

The increasing popularity of electric vehicles has led to an increase in the need for batteries. Often, these battery cells and/or batteries are imported from Asia and it is mainly about price and not about safety. This has to change, because it can lead to dangerous situations, says T&M Consultant André Handgraaf of TT&MS. More attention from the industry would be a good step in the right direction.

TESTING BATTERIES AND BATTERY CELLS

Testing batteries and battery cells for safety is very important. Many people will remember the images of the Tesla whose battery burned out. It is essential to test the safety of batteries, because you want to avoid that kind of situation. It also plays a role that more and more means of transport use electric batteries. Electric bicycles are still gaining in popularity, and the electric scooter is also appearing more and more often on the street scene. If the battery cells of these vehicles become overheated, you are faced with a major problem.

Many battery cells come from Asia and there appears to be little attention paid to safety testing. A battery cell insulation test and an impedance test are simple tests that can be carried out quickly and take little time. Often, however, the choice is made not to test. A question of time and money. However, if the cells are defective, life-threatening situations can arise. Putting out a battery in a non-test environment is a hopeless task. There is also room for improvement in Europe. Cells that arrive in batches of thousands of units do not all undergo a test. And even after assembling a battery module or pack, it is just wise to go through a test routine before shipping.

IMAGE LOSS

Unfortunately, there is still no requirement for testing and safe storage of batteries. New guidelines are being drafted and there are many recommendations, but there is no legal standard yet. (The PGS-373 is still being worked on).
Strangely enough, even the better known manufacturers do not all choose to have their batteries tested. Many battery accidents do not make the headlines, so the brand in question suffers no damage to its image. If these cases hit the headlines more often, it would certainly have an impact on businesses. More attention should be paid to the importance of safety testing.

Quality marks

There should be a quality mark on batteries. With such a sticker you would know immediately whether the product in question is safe. The first step, however, is to create awareness. A safe test environment is needed, and these are still scarce. Weiss Technik has developed special climate cabinets for safely testing batteries. The company Hiltra has developed specific cabinets for the safe storage of batteries. In the event of a fire, there will be no damage to the building. Special extinguishers for lithium batteries are now also available. In addition to safety, the capacity of the battery is a point of concern. The following questions should definitely be asked when it comes to batteries. How long does a battery actually last in the number of charge and discharge cycles? The higher the charge voltage (above 4.2V), the shorter the life and the higher the risk of overcharging and overheating. And the same applies to the minimum battery voltage. Do you discharge the battery to 3.0V, 2.8V or even lower? This affects the capacity calculation but has a negative impact on the lifespan. These tests are usually done by the battery manufacturer.

SPECIFICATIONS

Like safety tests, however, they are rarely asked for in the industry. How are specifications defined and specified? The specifications should provide clarity to the customer, but the correct provision of information is still lacking. Action is needed from the industry to create more awareness of safe batteries and battery storage.

MORE INFORMATION

On this specific subject we would like to refer you to our knowledge pages. We cover for example the subject of battery testing and the associated safe test environment. But we also cover the testing of battery cells, battery modules, battery packs and the examples of battery testing software/test systems. We also recommend the complete presentation we made for the Energy Storage Event 2020, ‘Testing Li-ion Batteries‘.

If you would like more information, please contact one of our consultants.