Updated Water Leak Tests Can Save Vehicles – and Lives

Battery systems in today’s electric vehicles often are evaluated using outdated water-leak tests performed before being shipped to dealers. That means the industry could be ignoring inherent dangers to EV drivers or passengers.

However, advanced leak-test methods can save vehicles – and lives, supplier executives say.

“The market for electric vehicles is booming,” says Thomas Parker, North American automotive sales manager at INFICON’s U.S. headquarters in Syracuse, NY. “Leak testing is the key to achieving quality throughout vehicle-production processes – from battery-cell manufacture to assembly.”

Millions of leak-detection tests are conducted yearly on safety-related components, including airbags, fuel tanks, batteries and driveline parts before models hit dealership showrooms.

Still, about 80% of suppliers and testing shops are using outdated leak-detection equipment and processes when testing batteries in new EVs, according to an INFICON study.

INFICON (Instruments for Intelligent Control) is a leading global supplier of leak-detection technology in air conditioning, auto production and refrigeration applications. The company has multiple manufacturing facilities in Europe, China and the U.S.

Suppliers or technical experts building the cells, cooling circuits and final battery pack are responsible for leak testing, but no one process fits all leak tests, Parker says. Outdated methods such as soap-water washing of battery packs are the norm, but water can cause battery malfunctions, he says.

“Water is like Kryptonite for today’s EV battery,” says Parker (pictured below, left).

In this age of electromobility, “consumers won’t (like) spending more money to replace a traction battery after a few years’ use. And they definitely don’t want their EV to catch fire,” he says.

With under-warranty vehicles, dealerships assume costs of battery leak testing, but they can back-charge the automaker. With expired warranties, costs revert to customers.

INFICON looks for defects by filling each traction battery cell with electrolytes, then testing them for leaks after being sealed into a container to prevent moisture from entering from the outside.

Leak testing has been conducted routinely by dunking parts and assemblies into water, allowing bubbles to rise.

Instead, INFICON uses repeatable methods such as tracer gas leak detection systems that work for hydrogen and refrigerant.

Cost can be a factor. “Better leak testing is an additional cost,” Parker says. “Unless the OE pushes for improvement (many times they do) or the supplier has seen issues, suppliers typically do the minimum.”

In some cases the cost to helium leak-test is less than a dollar on a part that might sell for $100, or a complete battery pack test can run several thousand dollars.”  

A publicly traded company, INFICON has 414 employees in North America and about 1,030 globally. INFICON saw robust overall market sales in 2017 of $374 million. The company is projecting $400 million in overall sales in 2018, plus at least a 19% increase in operating income from 2017, according to April 2018 INFICON earnings reports.