Eric Boor is a laid back guy who has been senior Operations Manager Battery Systems Lab in Warren for years. In short, he knows exactly what's going on at the secure facility of auto giant General Motors about half an hour outside of Detroit. Nothing less than the electric future of General Motors will be decided here. Eric Boor is apparently one of the few GM employees today who have turned their backs on working from home. There are only a handful of employee cars in the two large parking lots on Van Dyke Avenue and the offices are almost deserted. "Here in Warren, the batteries are tested long before they get into our electric cars," explains Boor after a short briefing in one of the laboratories on the ground floor. "We test seven days a week, 24 hours a day, 365 days a year. 500 people normally work in this part of the development center alone – currently many of them seem to be working from home, because it is a normal Wednesday and there is no break in sight.
“We take the batteries and the cells apart ourselves, put them back together, analyze and test – test again and again,” Boor suddenly becomes more serious, “the cell and the battery simply decide everything in an electric car. We don't want to be behind there. That's why we test the modules for three years before they find their way into one of our models." The batteries are not only scrutinized in the laboratory, but also repeatedly shipped to the prototypes, which are sold under each of the GM brands gondolas in three-digit numbers all over the world to collect test kilometers.
In one of the next rooms there are huge climate chambers - around four by four meters in size and almost six meters long. In them, almost any climate on earth can be simulated at the touch of a button. With their microcosm, the blue chambers of CZS Cincinnati are larger than most garages. Eric Boor opens one of the double doors and looks at a powerful battery pack on the ground: “Our currently largest battery pack is being tested here. The one from the GMC Hummer EV weighs 910 kilograms and has an output of 208 kWh.” Humidity of 5 to 95 percent and temperatures of minus 67 to plus 89 degrees Celsius can be simulated in the climate boxes. In addition, the battery packs are also used particularly hard in off-road prototypes, because nothing can go wrong off-road. For this purpose, General Motor has brought one of the largest vibratory plates in its own laboratory that exists anywhere in the world. A twin model is available from aircraft manufacturer Boeing, which uses it to oscillate engines and wing components weighing up to five tons at 2,000 Hertz. At GM, it's battery packs that are stressed in all directions with an output of 1,500 kilowatts for seven to 14 days so that nothing goes wrong afterwards in the real life of the vehicle.
In the next CZS box, the battery pack of the new Cadillac Lyriq has to show what it can do at around 40 degrees Celsius. When you look through the armored glass, you can hardly see that the battery pack has to work hard under desert conditions. The 104 kWh battery module comes from the supplier LG Chem, weighs 631 kilograms, has a volume of 534 liters and consists of 288 cells. The luxury crossover Lyriq is one of Cadillac's great hopes. It should finally stand up to the European premium competition once again and attract new customers to the brand from Detroit. This should not only work with design and workmanship, but also with the electric drive. "Touch strictly prohibited!" - the Americans are more precise than accurate with their warnings that stick everywhere. In any case, only those with an orange badge on their clothing are allowed to work on the climate boxes. "There is a clear goal for all of us here," the cheerful Eric Boor suddenly becomes serious again, "the customer wants a fully charged electric car in eight to ten minutes - like a combustion engine. That's what we're working on here."
But for the car manufacturers, it's not just about the customers, but of course also about their own earnings. "A common cell is the be-all and end-all for electric cars," explains Tim Grewe, Director of Electrification at General Motors, "ultimately it's all about full-size trucks because they make the largest volume for us. But of course the whole thing is also important for autonomous vehicles. We learn here in the Tech Center with every step we take.” Ultimate is the name of the standard cell format at General Motors. "The cell is the DNA of an electric car," adds Tim Grewe, "the height of the cell is determined by the SUV and pick-up." In order to react quickly and avoid friction losses, the supplier LG Chem is at General Motors directly involved in cell testing and working on site in the battery lab in Warren. The new flagship of the Cadillac Lyriq with its 104 kWh battery pack offers a battery output of 620 watts per liter. "In the long term, 850 or even up to 1,100 watts are possible," says Grewe happily, "then the batteries will be smaller and of course lighter. That is also important for the costs.” If a little more battery capacity is required, as with the gigantic GMC Hummer EV, two packages are stacked on top of each other. The gigantic electric vehicle is operated with 400 volts - charged with 800 volts so that this happens as quickly as possible.
Tim Grewe has to smile when he hears again and again that there are no moving parts in the batteries, but that 25 kilograms of lithium are ultimately moved in the batteries to retrieve the energy for the electric car's propulsion. The developments in the field of battery technology are progressing at high speed - not only at General Motors and especially at the large suppliers. Compared to the battery pack of the Chevrolet Bolt from 2016, the weight has dropped by 40 percent - also because of the developments in Warren. Warren is working day and night to ensure that things continue at full speed – soon maybe not just from home again.
