GM works to ensure its new Hummer EV avoids battery defects

DETROIT – As General Motors scrambles to repair defects that caused fires in at least 13 Chevrolet Bolt EVs, the automaker is aggressively working to ensure the same problems don’t seep into its next-generation Ultium batteries and its highly anticipated relaunch of an all-electric version of the Hummer this fall.

The new power system is crucial to the automaker’s future as it pivots to exclusively offer electric vehicles by 2035. The batteries and the company’s entire Ultium system – platforms, motors and other components – are expected to underpin every EV for GM for the foreseeable future.

Problems with the Bolt – the company’s flagship mainstream EV – have led the automaker to recall every one of the electric cars since production began in 2016. Fixing the vehicles, including completely replacing some batteries entirely, is expected to cost $1.8 billion.

That expense – averaging roughly $13,000 per vehicle – highlights a gamble for automakers planning to use common platforms or battery cells to power massive amounts of vehicles. If there’s a problem, it’s going to be costly.

It’s one of the reasons officials throughout GM have aggressively been working “around the clock” to fix the issues and ensure future electric vehicles such as the GMC Hummer EV and Cadillac Lyriq — two of the first GM models to use its Ultium batteries — don’t have the same problems. They’re also working on wireless technology that will enable GM to detect potential defects sooner.

“There’s a commitment across the company to not only address the issue with the LG cells and the Bolt but also make sure that all the future products are set up for success,” Mike Harpster, chief engineer of electrification propulsion for GM, told CNBC during a deep dive into the automaker’s upcoming Lyriq. “There’s not creating the fault or defect, but there’s also how the pack and the vehicle respond to it. And on both those fronts, we’re moving very aggressive.”

The automaker’s efforts stretch outside of its own organization. GM Chief Financial Officer Paul Jacobson recently said GM engineers are working with LG Chem, which makes the batteries, to “clean up the manufacturing process” and implement some “GM quality metrics” at LG’s plants.

GM on Monday announced fixes to the manufacturing process of the battery cells as well as updated monitoring software for the vehicles. Both are expected to be used for future vehicles, Tim Grewe, director of GM’s electrification strategy, told reporters Monday.

GM is pursuing reimbursement from LG, which produced the defective parts at plants in South Korea and Michigan.

The increased quality efforts come as GM is building a U.S.-based battery cell plant through a joint venture in Ohio with LG Chem called Ultium Cells. It’s the first of several battery plants…