Testing & qualifying capacitors: our methodology applied

Testing & qualifying capacitors: our methodology applied

Energy storage is a major component in the research into energy saving and CO2 reduction. However, the technology has not reached full maturity yet. We are faced more and more with the limits of traditional batteries. Fortunately, alternatives are being introduced. Capacitors are being hyped as the new batteries – at least for applications where a quick energy boost is required. Capacitors have a much longer lifespan and are safer than traditional lithium-ion cells, because they don’t involve chemical processes. Flanders Make developed a method to test and qualify the power or capacity of capacitors. Here’s an update on the situation.

Charge and discharge a million times

A capacitor is an electronic component in which an electrical charge can be stored. As such, a capacitor is similar to a battery, but it still has a different function. A battery uses chemical processes to store energy and release it slowly. Sometimes, this process can take years. Depending on the application and the size of the battery, it can last a very long time in certain cases. As a rule, capacitors release the stored energy very quickly. A good example is the flash of a photo camera. Here, a capacitor uses the energy from the camera battery and releases it in a fraction of a second to make beautiful pictures. Capacitors charge more quickly and charging cycles exceeding one million are not unusual. Moreover, unlike batteries, they remain perfectly operational at extreme temperatures, from -40°C to +65°C. Finally, capacitors are much lighter than batteries, and this would, for instance, reduce the total weight of a vehicle considerably.


In theory, though, because in practice, capacitors will not replace all batteries right away. For applications where a constant flow of energy is required, such as an electric car, batteries still remain the preferred option, for now. However, they are more and more complemented by capacitors, which store braking energy, among others. Therefore, capacitors are a good solution for short, frequent trips, like in a hybrid city bus.

The new generation of capacitors lays the bridge to lithium-ion cells by combining the energy storage capacity of a battery with the lifespan of a capacitor. However, the performance and reliability of these new “ultracaps” (a.k.a. power capacitors or supercapacitors) have not been fully established yet.


Flanders Make, the research centre for industry, developed a methodology for the accurate testing and qualification of capacitors, with which we carry out the following tests:

  • Lifespan tests
  • Performance tests
  • Reliability analyses

The methodology is based on physical failure models. These are generic solutions for generic reliability issues of electronic components. As a result, manufacturers can considerably improve the reliability of products with electronics, and reduce development costs and times without increasing production costs.


Meanwhile, the research resulted in the creation of a battery lab by Flanders Make in Lommel, to complement the existing battery lab at the Free University of Brussels (VUB). Three partners have already been using the results and infrastructure.

Jabil, a manufacturer of electronic appliances, used the methodology to build an economically efficient test rig of their own to establish the lifespan of capacitors.

Technology supplier Connect Group applied the measuring method to establish the quality of stock items which they were unsure of. The parts that passed the reliability test were integrated in a large-scale industrial project of one of Connect’s customers. This enabled the business to increase its competitiveness by offering high-quality products with short delivery periods.

The technology company Altreonic-kurt.energy is active in clean energy systems. One of the building blocks used are carbon-based power capacitors. Altreonic-kurt.energy carried out stress tests on their power capacitors in the Flanders Make battery lab. The purpose was to get a better grasp of the properties of carbon-based power capacitors in extreme conditions: with fluctuating temperatures and fast charging cycles. These tests showed that power capacitors have an energy capacity that is similar to lithium-ion cells, but last 10 to 20 times longer. They can release a much greater energy capacity without major temperature increase. At a lower capacity, in combination with extra cooling, the energy is released continuously without safety risk. The power capacitors of Altreonic-kurt.energy withstood the stress test with flying colours!

More information?

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