- Battery lab in Tennessee is one of just four VW facilities in the world
- Facility replicates extreme climate conditions on lithium-ion battery packs
- Research and development focuses on high-voltage battery charging and output
- The lab is on the same grounds as VW’s US$800 million Chattanooga EV manufacturing plant
As the hot lithium-ion battery pack was suspended over the eight cubic metres of cold water, I wished all those listeners to my Plugged In podcast who write in to point out that water contacting an EVs battery will render it useless, if not worse, were standing beside me in this impressive testing facility.
Five minutes later, as our tour stopped in front of the drive-in temperature chamber, I thought of other EV skeptics I’ve come across over the years who dismissed the possibilities of an electric vehicle operating in hot and cold climates. Particularly when our guide noted that the temperature that the battery packs, and in fact entire vehicles, were subjected to in the big oven/freezer ranged between 180-degrees C and -80 C.
A hot battery pack is lowered into the 2,113 gallon cold water immersion tank at the VW Battery Engineering Lab in Chattanooga, TN. The test is to simulate water ingress from weather events and accidents. CREDIT: Andrew McCredie Photo by Andrew McCredie
These and other, as one engineer put it, “abusive” tests are what takes place under the roof of Volkswagen’s new, 32,000 sq. ft North American Battery Lab in Chattanooga, Tennessee. Just a few hundred metres away, the company’s US$800-million EV manufacturing plant is up and running and pumping out 2023 VW ID.4s for the North American market, and soon the ID.Buzz and ID.Aero will be rolling off the production line too. So, the location of the US$22-million lab makes perfect sense. It is one of four such VW battery testing facilities in the world, with the others in Germany (Braunschweig) and China (Changchun, Shanghai). And while all four labs are currently focused on getting a better understanding about emerging battery technologies, particularly in terms of the company’s MEB architecture, VW engineers may one day be doing tests on all kinds of prototype and production vehicles in their state-of-the-art laboratories.
In addition to the extreme water and temperature tests, engineers have at their disposal some very advanced bespoke equipment. Perhaps the most impressive, and certainly the most expensive and most ‘engineered,’ is the one-of-its-kind multi-axial shaker table. A massive pit was dug and filled with concrete to provide a base for the machine, which can create vibrations that, without that footing, could cause earthquakes in the surrounding area. As such, all that gets shaken is the battery pack, with the shaker table able to simulate some 15,000 kilometres — about the average for one year – in just one week’s time.
The shaker table test simulates some serious bumping and jostling to a battery pack, and can simulate 14,500 kilometres of rough road travel in one week’s time. Photo by Andrew McCredie
The shaker table test simulator is housed in this big test room with a massive concrete foundation. Photo by Andrew McCredie
In addition to testing battery packs — between -80 and 180 C — the drive-in temperature chamber can fit an entire large SUV for testing. CREDIT: Andrew McCredie Photo by Andrew McCredie
A fire box is used for safety reasons during high-voltage charging tests. Photo by Andrew McCredie
A VW ID.4 parked over an inductive charger outside in the lab’s parking lot. Photo by Andrew McCredie
The US$22-million lab is one of just four built by Volkswagen for EV battery research, development and testing. Photo by Andrew McCredie
The battery architecture from an ID.4 awaiting cells to be fitted for testing. Photo by Andrew McCredie
Then there is the thermal-shock chamber, which is designed to turn up the heat on a battery pack on one side of the chamber, then quickly — 15 seconds we were told — transfer it to the cold chamber. This test is to see how the pack’s welds and fasteners hold up to swings in temperatures between 70 C and -40 C. The test runs 40 cycles in three days, some 17 days less than previous thermal shock tests. And the dust test uses, I kid you not, ‘Arizona-certified’ dust with particles 1/70th the width of a human hair to create abrasive interaction to test battery seals.
According to Volkswagen of America EVP and Chief Engineering Officer Wolfgang Demmelbauer-Ebner, the lab is all about creating safe, strong and reliable electric vehicles, and it allows “(us to) react quickly to the fast-paced EV market by applying data to our local engineering and assembly.”
One last note about this facility, a sort of Disneyland for engineers. As with most ever facet of electric vehicle manufacturing, sustainability is top of mind. For instance, when batteries are discharged during testing, the energy produced is transferred back into the building and local public grid, and all scrapped materials are recycled.
Keyword: Volkswagen's Battery Engineering Lab tests lithium-ion packs to the extremes