Test adapter set of pressure compensation elements for leak testing of HV batteries

In order to increase the range of electric cars, the energy density of the battery cells is constantly increasing. At the same time, housings are becoming increasingly lighter, thinner-walled and therefore more pressure-sensitive. That is why the housing of HV batteries must be ventilated and ventilated, among other things, during uphill and downhill journeys, in different operating states or to equalize the temperature. Until now, this was usually done by a porous PTFE film. However, this reacts sensitively to mechanical influences and contamination and can impair the air permeability and ultimately the pressure equalization function in normal operation.

Gases or excessive heat can suddenly develop in the casings of batteries in the event of an accident or due to foreign objects. To do this, pressure and heat must be able to escape suddenly, otherwise the housing risks bursting. A danger for the vehicle and its occupants. That's why every battery needs 100 percent reliable emergency degassing. Until now, this was only possible if a rupture disk was punctured by a pin under appropriate pressure differences and was therefore worn out or inoperable.

Recently, pressure compensation elements (e.g. from the manufacturers DIAvent, Freudenberg Sealing Technologies, etc.) have become increasingly popular . the two functions

• Ventilation and ventilation as well
• Emergency degassing

combine in one component. The big advantage: These pressure compensation elements are suitable for long-term use, do not wear out and can continue to be used even after an emergency. These pressure compensation elements are independent components that are locked or screwed.

Why do these pressure compensation elements have to be removed and installed?

During the leak test of an HV battery, these components must be removed because the leak test pressure is higher than the response pressure of the pressure compensation elements. The test pressure would therefore be reduced via the pressure compensation elements and thus only one limited Make leak testing possible.

How do the pressure compensation elements have to be removed and installed?

In order to ensure an unrestricted leak test (according to the specifications) , must do that Original component Remove the “pressure relief valve” with the appropriate OEW 02 tool for loosening and assembling the pressure compensation elements and replace it with one Test cap / test adapter PSBG 01_LR be replaced.

What are the test cap and test adapter needed for?

• The test cap – in case the test pressure is introduced or measured elsewhere (in the HV battery housing).
• The test adapter - in case the test pressure has to be introduced via the opening of the DAE.
• Test cap and test adapter - in the event that two pressure compensation elements are installed on an HV battery .