Porsche Taycan and Audi E-Tron GT electric cars are being recalled to address a battery-sealant issue.

The two EVs are based on the same J1 platform and share many major components—including battery sealant. Both Porsche and Audi switched to a Teroson sealant during the period when the affected cars were produced, and it may have been applied in insufficient amounts around the battery pack, according to documents filed to the National Highway Traffic Safety Administration (NHTSA). That "can allow liquid to accumulate in the battery."

The recall covers 4,777 Taycans built between Sept. 23, 2022, and Aug. 3, 2023, and 1,899 E-Tron GT vehicles built between that start date and Aug. 28, 2023. All vehicles built before and after those dates are unaffected.

2023 Audi E-Tron GT

2023 Audi E-Tron GT

The NHTSA estimates that 3% of the affected vehicles have the battery-sealant defect. The recall population includes most Taycan variants, encompassing the sedan and Cross Turismo/Sport Turismo wagon body styles. Both the base E-Tron GT and the RS E-Tron GT performance model are included in the recall as well.

"Dealers will test the battery for leakage and replace the battery as necessary, free of charge," according to the NHTSA. So it seems some owners may end up with new battery packs. It's unclear of a specific supplier is on the hook here, but if large numbers of battery packs need to be replaced, this could turn into a very expensive mistake.

These models were among the first to have 800-volt charging, but the issue has nothing to do with that. They're also not the first EVs to be recalled for a battery-sealant issue.

2023 Porsche Taycan

2023 Porsche Taycan

The GMC Hummer EV was also recalled last year for battery sealing problems, in this case because surfaces to which the sealant was applied weren't properly prepped, meaning the sealant didn't stick well enough. And Audi's E-Tron SUV was recalled in 2019 for what sounds like a similar issue. At that time the automaker warned that the condition could cause "a thermal event."

It's quite a different battery issue than the recalls of packs using LG Energy Solution cells in a number of models, most of which appear to be related to the cells themselves—and in some cases including the Chevrolet Bolt EV involving manufacturing issues. That led to a $1.9 billion payment to General Motors to help cover the recall costs—with many Bolt EV buyers getting new vehicles.