Why Is My Electric Vehicle Dead? Check the 12-Volt Battery

livemint.com:

When David Finkelstein and his wife first got their new Hyundai EV, they drove it for months without a hitch. Then, the Ioniq 5 SUV started to repeatedly fail, rendering it inoperable. He couldn’t even open the door at times.

“I had no idea what was going on," said Finkelstein, adding that the electric vehicle’s lithium-ion battery had been charged. Turns out, the problem wasn’t with the main battery, but the smaller, low-voltage one—the kind that has been found under the hood for decades. In some new electric-car models, these 12-volt batteries are dying repeatedly and unexpectedly, leaving drivers stranded and needing a jump to get going again.

It isn’t clear how widespread the issue is. But it has taken many owners by surprise, led to numerous complaints online and affected some high-profile EV launches in recent years from major car brands, such as Hyundai, Rivian and Cadillac. It also has prompted at least two regulatory probes.

While these batteries don’t move the vehicles themselves, they do provide juice to the interior lights and electronics, which in EVs tend to be far more sophisticated and power-hungry. As a result, the 12-volt batteries are “almost always on" and deplete faster than those in gas-powered vehicles, said Amod Kumar, an industry analyst at research firm S&P Global Mobility. Some car companies have also struggled with software glitches and other hardware problems that have accelerated the drain on the battery, even when the car is in park.

In Finkelstein’s case, Hyundai ended up repurchasing his 2022 Ioniq 5 because of the repeated 12-volt battery troubles, he said. A Hyundai spokeswoman declined to comment on his experience. More frustrating for consumers is that these batteries are dying