The company issued a voluntary recall of approximately 540 E-Tron SUV models sold in the U.S. because of a risk that moisture can seep into the battery cell through a wiring harness glitch, spokesman Mark Dahncke said. The company isn’t aware of any fires or injuries because of the flaw, which affects a total of 1,644 models, he said.

The E-Tron, which went on sale in the U.S. in April, is Audi’s first fully-electric car and one in a wave of contenders from traditional automakers looking to challenge Tesla Inc.’s dominance of the segment. While electric vehicles are no more prone to accidents or fires than gasoline-powered cars — and might be less so, according the National Highway Traffic Safety Administration — the lithium-ion battery technology that powers them is still evolving, and there is no consensus on safe system design.

Audi said there have been five instances globally where a battery fault light turned on because of the moisture issue. It began contacting E-Tron owners in the U.S. last week, prior to a warning from federal safety regulators, and should have a repair available by August.

“We are applying an abundance of caution as no such incidents have been reported globally,” the company said in a statement.

Audi said it’s offering E-Tron owners loaner vehicles and an $800 cash card to cover gas or incidentals during the recall period, as well as free roadside assistance. There are still E-Trons unaffected by the recall available for sale, it said.

More must-read stories from Fortune:

—Audi recalled 75,000 vehicles in March due to fire risk

—From September 2018: Audi’s all-electric SUV is Germany’s first serious shot across Tesla’s bow

—The Renault deal is dead, but Fiat Chrysler still desperately needs a partner

—GM is planning electric cars that won’t give buyers sticker shock

—Listen to our new audio briefing, Fortune 500 Daily

Follow Fortune on Flipboard to stay up-to-date on the latest news and analysis.