HV battery housing leak test

The main task of the HV battery housing is to protect the cells, electronics, power electronics etc. from external influences. A suitable battery housing gives stability to all components inside an HV battery and protects them from dirt and moisture. A tight battery housing thus provides short-term protection, e.g. when driving through water puddles, mud and snow, and medium- and long-term protection against corrosion inside the HV battery or HV component.

If moisture and dirt penetrate a HV component from the environment, immediate short circuits can occur inside the affected HV component.  Corrosion can also lead to short circuits as a consequence. 

The tightness of the HV battery housing must be checked inside the HV battery/HV component during servicing and after every maintenance work. The leak test is mandatory after e.g. battery stacks have been replaced and generally after every opening and closing procedure of a HV component. All HV electrical connectors of a HV system are equipped with special seals that prevent the ingress of water and dirt.

The two relevant test methods Methods for leak testing HV component enclosures are:

• the pressure drop method
• the flow-through method or mass flow

In the pressure decay method, a specific test pressure is introduced into the HV battery housing. After a specified time, the pressure drop is determined. The pressure drop is a measure of the tightness of a HV component.

• The following products from Autotestgeräte Leitenberger can be used for the pressure drop method
  • Leak test sets for HV battery housings (LTBG... / LTBGD...)
  • Leak test of housings and components (LTA 01)

In the flow-through method, a certain test pressure is maintained stably in the HV component. Leaks reduce the pressure or vacuum inside the test item. The air or test gas supplied from outside keeps the test pressure in the test item constant. The supplied air or test gas quantity is determined. The determined air or test gas quantity corresponds to the leakage rate of a test item.

• The following products from Autotestgeräte Leitenberger can be used for the flow method
  • Flow meter with digital pressure measurement and display (DFG 200)