GM to install onboard battery diagnostics on all future EVs to predict fires

GM will install onboard battery diagnostic software in all its future electric vehicles across various brands. A recall of thousands of 2017 through 2019 Chevrolet Bolt EVs for battery fire potential led to an exerted effort by hundreds of engineers to create the fix. (Chevrolet)

General Motors revealed that onboard diagnostic software to detect electric vehicle battery anomalies will be standard on all future GM EV vehicles, a move that could potentially lessen customers worries about EV battery fires as the carmaker launches 30 EV models by the end of 2025.

If a problem is diagnosed, the software will warn the driver with an illuminated warning lamp on the gauge cluster and drivers would need to have the vehicle towed to a dealer for further analysis, GM told Fierce Electronics on Monday. 

The sweeping decision potentially affects hundreds of thousands of EVs in coming years. It was only mentioned briefly at the end of a short statement issued last week that said GM was installing the diagnostic software into 69,000 Bolt hatchbacks from the 2017 to 2019 models Chevrolet Bolts that had been recalled after reports that five of them caught fire. Two people suffered smoke inhalation and a house was set ablaze.

The diagnostic software “has the ability to detect potential issues related to changes in battery module performance before problems can develop,” GM said.

GM said customers of 2019 model year Bolt EVs could get the remedy immediately, while owners of 2017 and 2018 model year Bolts will be eligible to get the remedy by the end of May.

“We will also be making the advanced diagnostic software available to all other Bolt EV owners in the coming months,” GM said. “Additionally, we will be making this diagnostic software standard in the 2022 Bolt EV and EUV, as well as future GM electric vehicles.”

GM spokesman Dan Flores told Fierce Electronics on Monday that the onboard diagnostic capability applies to “all GM EVs going forward including all new Bolt and Bolt EUVs.”

Flores said the feature is designed to “provide added peace of mind” to owners and drivers. “GM has developed tools to allow dealers to diagnose battery issues as well as advanced onboard diagnostic software that, among other things, has the ability to detect potential issues related to changes in battery module performance before they become potential problems during vehicle operation and charging.”

Based on the nature of the battery problem, the diagnostics will command different warnings to the driver and different responses from the vehicle. “In all cases, the diagnostics illuminate a warning lamp on the vehicle’s gauge cluster,” he said.

“In the rare event that a customer’s vehicle detects an issue with the battery, the driver would see a “Service Vehicle Soon” service light illuminate on the vehicle’s instrument panel,” he said. “Although we have found no incidents [of fires] occurring while driving, in the rare event that the vehicle detects an issue while operating, the vehicle will also go into reduced propulsion mode  and the vehicle’s range will be limited to 15 miles or less. If this were to occur, we would ask our customers to contact their dealer or the Chevrolet Roadside Assistance team at  at 1-800-243-8872 to have their vehicle towed to the dealer for further analysis of the issue.”

If the vehicle detects a battery concern while charging, it will stop charge charging and the vehicle will not be able to restart until the issue is addressed, Flores explained. The Service Vehicle Soon light would also illuminate.  Again, customers would contact their dealer or the toll free number to have the vehicle towed to the dealer for further analysis.

It took “hundreds of engineers working around the clock” to build the state-of-the-art diagnostic software, GM said in early April.   Each Bolt has 288 battery cells and engineers analyzed data from hundreds of thousands of cells.

GM issued the recall of nearly 51,000 of the affected Bolts last fall, noting the potential of an unattended fire in the high-voltage battery pack under the back seat’s bottom cushion, according to the National Highway Traffic Safety Administration. The NHTSA also linked to GM’s statement on the new diagnostic software.

The vehicle’s cell packs in the recall have the potential to smoke and ignite internally. The GM recall applied to Bolts with high voltage batteries produced at LG Chem’s Ochang, Korea, factory. Those batteries may pose a risk when charged to full or very close to full capacity. Before the diagnostic fix was announced, dealers were given a software update to limit the vehicles to 90% of a full charge. Once the final recall repairs are made with the diagnostic software, the Bolts’ full range will be restored, giving some of the older Bolts up to about 240 miles per charge.

GM has not revealed technical details of its diagnostic remedy, but it appears the approach goes beyond the ability of typical Battery Management Systems that monitor voltage, temperature and wear in battery cells. Some smaller companies have approaches such as a Metis Engineering’s Controller Area Network-based sensor to detect small increase in pressure inside a battery cell that can be caused by rising temperature when a cell is overworked or has been damaged.

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Joe Holdsworth, managing director of Metis said that detecting early onset of battery failure in EVs will be critical to allow the auto industry to maintain its rate of EV growth. “Detection will significantly reduce the risk of catastrophic battery failures,” he said in a statement.

The diagnostic software approach seems to have arrived just in time, especially for GM, which has gone all-in for EVs and has committed $27 billion in EV and autonomous vehicle development through 2025, including $7 billion in 2021.  The 30 EVs that GM plans to launch through 2025 include Cadillac, GMS, Chevrolet and Buick models with all price points.    Last week, GM introduced Ultium Charge 360 to integrate charging networks, GM vehicle mobile apps and other products and services to simplify the charging experience.

President Biden has made the expansion of EVs a central tenant of his energy and infrastructure proposals and  has called for construction of 500,000 charging stations nationwide.

Analysts have been hopeful that GM’s approach can be adopted by other carmakers. BMW recalled 10 BMW and Mini plug-in models in the U.S. last fall and Hyundai recalled Kona Electric SUVs in the States. Underwriters Laboratories estimates about one in 12 million lithium-ion cells have caught fire, but that is a significant percentage given there are up to 8 billion cells produced each year.

When asked if GM’s onboard diagnostic software for EV batteries could be shared or sold with the industry at large, Flores said he did not know. “It’s nothing we are considering at this time,” he said.

Even with the diagnostic approach, some EV enthusiasts believe the EVs should be made with solid-state batteries that contain no electrolyte used in Lithium-Ion batteries to make them safer. Toyota is working with Panasonic on a limited production vehicle using a solid-state battery to be available by 2025, while VW is working with QuantumScape on a solid-state battery for an EV as early as 2024.