GM is working with its supplier, Magna, to build battery enclosures for its upcoming Hummer EV. The 345,000 square foot facility is expected to add 300 jobs to the city of St. Clair over the next 5 years.
“Bringing this new battery enclosure technology to market is another example of Magna’s ability to deliver a full-system solution to automakers supporting their focus on a lower emissions future,” said John Farrell, President of Cosma International, Magna’s body and chassis group. “The move toward electrification allows us to rethink what is possible and demonstrate how we can leverage our core strengths to continue bringing customers innovative solutions that help them meet their goals, no matter how challenging.”
Internal combustion engined (ICE) vehicles don’t need a special compartment for their drive systems. A double-barrier firewall is built into the space between the passenger compartment and the space under the hood, so the engine compartment is actually just part of the vehicle’s body. Engines and transmissions mount directly to the body or the frame, and connect to the vehicle’s suspension system. Most vehicles are open to the air below under the hood, allowing for air flow and easy access for maintenance. Some newer vehicles have a plastic air deflector, but it’s not air or water tight.
Electric vehicles can’t get away with that approach. DIYers doing conversions have often located battery banks under the vehicle’s hood where the ICE engine used to be, but the automakers had to find ways to keep water, salt, and other unwanted contaminants off the battery terminals and connectors. When a vehicle is built from the ground up to run on batteries, it’s important to keep the battery compartment as low as possible to get the best center of gravity, so the compartment usually mounts to the underside of the vehicle’s body.
This gives the battery compartment a complex shape. Not only does it need to be made to sling the batteries low on the bottom of the car, but it must also be rigid and strong enough to hold all of the weight of batteries. To do both of those things, a complex design is needed. They aren’t just metal boxes.
Given the requirement to both keep moisture and corrosives out, the box must be sealed, but there are things that must be allowed to go in and out. Electricity is the obvious one, and wiring must penetrate the box in some fashion. To allow for maintenance, the wires need to be able to be unplugged at that point, but the plugs and the holes going into the battery compartment must be watertight.
Unless you want the kind of problems Nissan LEAFs have had, you also need liquid battery cooling. This means pipes to and from a water pump and a radiator of some kind must go in and out of the compartment, and those holes must also be watertight.
It’s also a good idea to have some sort of emergency access to disconnect the pack’s high voltages in case of an accident or needed maintenance/repairs.
All of this needs to be built into one coherent package that can be removed should the vehicle require any maintenance or recalls in the future. Hundreds or thousands of battery cells, their modules, wiring, battery management electronics, charging electronics, and the cooling plates/pipes must all be built into one object that bolts neatly to the underside of the car.
So, no, Magna isn’t just building a box. It’s an object that’s almost as complex as an ICE, and it’s going to require a lot of work to crank these out on an industrial scale and send them on to GM to put in the vehicle. Battery cells from GM and LG Chem’s Ultium battery plant will have to be put into these enclosures along with all of their other guts, but I’m not sure if just the enclosures will be built at Magna’s new plant, or if they’ll be doing pack assembly as well.
Magna has been building other types of structures for a long time. Battery packs are new for most manufacturers, but things like floor pans, wheel wells, and other structures have been made for a long time. Doing these battery enclosures is right up their alley. They say they can build them out of steel, aluminum, or any other metal that’s needed for the job.
“This investment by Magna will create great jobs for our state’s talented workforce as we continue to implement our Michigan Back to Work plan to get Michiganders back on their feet,” said Governor Gretchen Whitmer. “This announcement reaffirms Michigan is transforming along with the automotive industry to ensure the next generation of mobility and electrification is designed, developed, tested, and built right here in our state.”