Then, as now, the company’s business model was power supply – a sector that continues to grow in importance today, covering everything from industrial power supply to energy storage devices and testing systems. Back in 1948, some cars were still powered by wood gas, and the first Beetles were running. Today, the company makes its money from electromobility.

"We are registering particularly strong demand for simulation and testing systems. We currently have more orders than we can handle," says Bernhard Rill, the company’s vice president. Rill and his colleagues are among the few suppliers in the car industry who don't need to worry about the future. "Our customers are buying bidirectional converters, which they can use to test and simulate batteries across the test spectrum." The car industry's push to develop electric cars is good news for the Bavarian engineers. "We can also test fuel cells, and we work with hybrid systems as well," notes Rill with pride. With 250 employees, the company is well positioned on the global car industry market. Some would say it holds a key position in those markets.

Porsche and NASA

Car makers have to test their batteries. These need to function reliably at high temperatures, under heavy load, or in challenging environments. "Our facilities test the limits of the battery to ensure long life and functionality. We put the battery packs through repeated charging and discharging cycles, often while they are being shaken about or exposed to high temperatures," explains Rill. These test sequences can last up to 12 months.

But it's not just the OEM who needs to run tests. Component suppliers also need these test facilities. Then there is the simulation of new powertrains: "They use our equipment for that, too." As they do, of course, for the end-of-line tests conducted on the factory floor. Klein's client list reads like a who's who of the German car industry, with names such as Porsche, BMW and Audi. High-profile test organizations ‒ for example, TÜV Süd ‒ are also on that list. But it's not just cars that depend increasingly on batteries. John Deere relies on technology from Gustav Klein, as does NASA, which uses the company's systems to simulate the performance of its rechargeable batteries.

But back to the car industry. Many manufacturers are also working on energy recovery systems for batteries. Wouldn't that be a lucrative market for the Bavarians? "Our systems are always bidirectional, so we can test that. But we don't believe that feeding energy from cars back into the grid is viable at the moment," argues Rill.

The idea unsettles customers, he claims. "Who wants to run down his own car battery?" As many in the in-dustry are quick to point out: a feed-in tariff payment of 10 euros is no use to a customer with a flat battery.

And what about the second-life business? "We collaborated with Daimler on the construction of Germany's largest second-life battery storage unit in Lünen, and supplied bidirectional converters for the 16 MWh facility," recalls Rill. A total of 3,240 battery modules from the second generation of smart electric drive vehicles are stored in Hannover, and pooled to form a stationary accumulator. "The venture was a success. But it's aimed at a mass market, and that's not something we want to get into. We're in the business of supplying customized solutions," says Rill, summing up the company's business strategy.