GM recalls Bolts, will replace battery modules

DETROIT — General Motors plans to recall certain Chevrolet Bolts for the second time in less than a year to replace defective battery modules after customers who completed a previous recall remedy continued to report battery fires.

GM did not say when the replacements would start.

"We're working with our supplier and manufacturing teams to determine how to best expedite battery capacity for module replacement under this recall," spokesman Dan Flores told Automotive News. "Teams are working around the clock to find ways to increase battery availability."

As GM targets an all-electric portfolio by 2035, the automaker has touted its early EV entry, the Bolt, which launched in 2016. The automaker more than doubled U.S. Bolt sales in the first half of this year and expanded into new markets.

GM and supplier LG Chem identified two rare manufacturing defects in the same battery cell, which has led to the fires, GM said in an emailed statement. GM believes those defects are related to production of the cells by LG in South Korea, said Flores. The defect could result in a heat source or a short in a cell, which could cause a fire.

Bolts built for the 2017 and 2018 model years used the LG Chem batteries made in South Korea. For the 2019 model year, some Bolts were built with the Korean batteries, while others used LG Chem batteries made in Holland, Mich. GM said Bolts built with the Michigan batteries were not affected.

The automaker in April developed a solution for the initial battery defect, six months after NHTSA launched an investigation into certain Bolts catching fire. A month after NHTSA began investigating, GM recalled 68,667 Bolts from the 2017 to 2019 model years.

GM developed a diagnostic tool to identify potential battery anomalies and replace battery-module assemblies as necessary. Dealers also installed advanced onboard diagnostic software that can detect potential issues related to changes in battery-module performance before problems occur.

Even after GM's fix, at least two Bolt drivers reported fires. In one case, a 2019 Bolt owned by Vermont Rep. Timothy Briglin, a supporter of EVs in the state Legislature, caught fire while charging in his driveway.

Until replacement battery parts are ready, GM is advising customers to return their vehicle to the 90 percent state of charge limitation using Hilltop Reserve mode (2017-18 model years) or Target Charge Level (2019 model year). GM also asks customers to charge their vehicle after each use and to avoid depleting their battery below 70 miles of remaining range. The automaker suggests that customers continue to park their vehicles outside immediately after charging and avoid overnight charging.

GM also recommends that customers who have not received the advanced diagnostics software, GM's initial battery remedy, visit their dealership for the update.

GM said 2020 Bolts are not affected because they were built with a different battery chemistry that increased range. All Bolts are powered by GM's previous-generation battery architecture, not the proprietary Ultium battery that will power its future EV lineup, which includes the GMC Hummer pickup and SUV, Cadillac Lyriq and Chevrolet Silverado EV.