Traction batteries for electric vehicles, which run on voltages of several hundred volts, must be well protected. Electrical components are packed into a thin-walled yet stable metal housing. Housings of this kind are equipped with at least one pressure compensation valve mostly in the form of microporous film. A second valve is a safety measure: It only opens if damage to one or several battery cells results from a malfunction, and the buildup of gases has to be released. A smart pressure compensation element, the "DIAvent", combines both functions into a single component.

Due to the growing energy density of battery systems in Electric Vehicle, the developers of lithium ion batteries must satisfy ever higher safety requirements. It is especially crucial to keep a single damaged cell from overheating the entire battery module. The goal is greater range without the battery growing in size and weight. If neighboring healthy cells also heat up due to the heat buildup, a chain reaction can result that, in the worst case, could lead the entire battery system to explode.

The traction battery is the core of an Electric Vehicle. In all circumstances, it is essential to protect its high-voltage components from moisture and dirt, even in long-term operation. At the same time, it must be possible to open battery housings for maintenance. That’s why automakers are turning to housings with a large cover that allows good access to all components. But the cross-section and dimensions of such seals must be adapted exactly to a specific battery. Changes are impossible without fabricating a new tool.