Chevy Bolt EV Battery Replacements Coming Soon in Fire-Risk Recall
General Motors said Monday it will start replacing battery modules in its Chevrolet Bolt EV electric cars as soon as next month, now that its battery supplier LG is again producing the necessary cells and modules. The company will first prioritize 2017–2019 Bolts built during times it believes defective cells were most likely to have been produced.
The replacements are the first long-term fix to address a recall underway since last November, when GM first identified 50,000 Bolt EVs from those model years that could have defective cells. The recall ultimately expanded to every Bolt EV and EUV made, a total of roughly 141,000 cars. Drivers of those cars have been advised to limit their charging, how deeply they discharge their batteries, and where and how they park their cars [see sidebar]. Owner discontent has surged, to the point that some Bolt EVs have been bought back by the company.
Now, a fix is in sight. GM said LG only resumed production of its cells and modules after it “implemented new manufacturing processes” in its plants in the Michigan cities of Holland and Hazel Park to eliminate two different defects in the cells, a torn anode tab and a folded separator, that could cause fires in the rare instance that both flaws occur in the same cell.
The companies didn’t provide further details about how the defects occurred or what specific changes to build processes had been made to eliminate them. But Tim Grewe, GM global electrification and battery systems director, confirmed during a media call that “interaction between the two [defects] is what causes the issue.”
Those same new manufacturing processes will be rolled out to all LG plants that supply cells to GM, the company said. GM will increase its frequency of individual cell checking, and work closely with LG to share manufacturing expertise in areas that apply to cell fabrication and assembly processes. It will also work with LG to “review and enhance its quality-assurance programs” as part of an effort to “provide confidence in its batteries” in the future.
GM said it is aware of 13 Bolt fires suspected to be linked to defective cells in the battery packs. No injuries or deaths are attributed to those fires, but all 141,000 Bolt EVs and EUVs built since December 2016 are being recalled. Meanwhile, GM has directed Bolt owners to follow specific recharging, usage, and parking protocols to reduce risk until their cars can be updated.
Production of both the Bolt EV and the new, larger Bolt EUV model was suspended last month. GM confirmed the Orion Assembly Plant’s lines will remain idle at least through the week of October 11 but didn’t give a date for resumption of Bolt production.
New Modules and Software Coming
As cell production under LG’s revised processes ramps up, GM will start to replace battery modules in existing Bolt vehicles. The company said it would “prioritize Chevy Bolt EV and EUV customers whose batteries were manufactured during specific build time frames” in which the company believes “the defects appear to be clustered.”
Affected Bolt EVs will receive a full set of new battery modules. Owners of 2017–2019 Bolt EVs whose modules are replaced will see the rated range of their cars rise from 238 to 259 miles. That comes from replacing the cars’ original cells with a newer and more energy-dense cell, boosting pack capacity from 60.0 to 65.0 kWh.
GM did not offer any estimates on how many vehicles it believed would require battery replacement, or how long the replacement of all affected Bolt modules would take. Chevrolet will notify “affected customers,” which is to say owners of existing Bolts, when new modules are available for their batteries.
Monitoring Batteries More Closely
Now that LG will be starting to supply replacement battery hardware, GM will also roll out new diagnostic software to be installed in every Bolt that monitors an expanded set of battery performance data. The goal is to look at more indicators than the existing software does, so the cars can alert drivers of any unusual readings in its battery’s electrical performance.
The program will detect “specific abnormalities that might indicate a damaged battery” and, GM says, will let the company prioritize damaged modules for replacement. Getting that software installed in a Bolt will require a visit to the Chevrolet dealership, however. Customers can start to schedule those visits in roughly 60 days, during the second half of November.
Meanwhile, the new software will limit charging to 80 percent of rated capacity until it has fully analyzed the behavior of all modules. After that, future diagnostic software to come will gradually increase the charge percentage as the pack continues to perform appropriately, with the final goal being to offer recharges up to 100 percent of capacity once again.
LG’s resumption of cell and module production under new, presumably defect-free, protocols may be the first shred of good news around the Bolt battery recall in quite some time. Since August 20, when the company expanded the recall to cover every Bolt built since 2016, Bloomberg reported that GM told some owners their Bolts should be parked at least 50 feet from other vehicles. That guidance has now been modified to “ample distance,” though how owners choose to interpret the advice will likely vary quite a lot based on their parking circumstances.
Automotive News published an editorial suggesting the only way for GM to restore public confidence in its EVs would be to provide entirely new battery packs for all Bolts that are based on the newer Ultium cell technology GM and LG have jointly developed. That would be a remarkably lengthy and ambitious undertaking, given Ultium’s different cell size and shape, different module design, and entirely different battery-management system. Meanwhile, Bolt drivers have at least two months to wait before both new hardware and new software will be available for installation.
What Should Bolt Owners Do?
GM has not changed its guidance on how Bolt owners should park, charge, and use their electric vehicles. Until replacement modules can be installed, it said, Bolt drivers should continue to:
- Use Target Charge Level mode to set vehicle to limit recharging to 90 percent of battery capacity. If customers can’t make change that setting, or aren’t comfortable doing so, they should visit their Chevrolet dealer to have these adjustments made;
- Charge more frequently and avoid depleting the battery below roughly 70 miles of range remaining, whenever possible;
- Never leave a vehicle charging overnight while indoors;
- Park the car outside immediately after charging; and
- Leave “ample space” around the parked vehicle where possible.