In the field of electromobility, it is essential that the battery and all supporting components used for battery and energy management function perfectly. The overall system consists of various components such as the battery, battery housing, electronic and power control units, electrical connections, venting elements, sensors, cooling circuits, pumps and control valves.

These components have to meet a variety of requirements. They are exposed to various environmental and operating conditions. Therefore, they must be leak-tight against moisture, which can lead to serious malfunctions.

To reduce this risk, these products are tested during the manufacturing process as part of the quality control.

Compressed air as a test medium is widely used in industrial leak and flow testing applications. A wide range of product types can be tested using different test methods. Depending on the test part volume, compressed air can be used up down to a leak rate of 10-3 mbar*l/s and to measure flow rates of up to approx. 200 l/min.

A variety of tests can be carried out using compressed air as the test medium. Leak tests using the differential pressure method or measurement of the mass flow. Flow tests to measure the volume flow with laminar flow elements or using the mass flow method.

In order to integrate a leak test test process into the production line, test parameters must be defined. These are the test pressure and the leak rate. Depending on the leak rate, a suitable test medium and test method must be selected to meet the technical requirement.

The use of compressed air as a test medium for 100% inline leak testing in industrial production lines is widespread. If a product must be watertight, a leak rate of 10-2 mbar*l/s is a commonly used assumption.

If the requirements are higher, tracer gas methods must be used. The following situation must be taken into account: If the product has a gross leak, the test environment is contaminated. And then it takes a while for the tracer gas concentration to drop and the tracer sensor to relax. It is therefore advisable to carry out a preliminary test with compressed air to detect gross leaks before filling the product with tracer gas and carrying out the leak test with tracer gas.

An overview of the methods for performing leak and flow tests of battery components is presented.