Electric vehicle drivers found that the nearest public charger was unusable in more than one in five charging attempts, according to an updated survey by J.D. Power, Kelley Blue Book (KBB) reported Tuesday.

J.D. Power had reported in August that 20% of more than 11,500 surveyed drivers failed to charge their vehicle at the nearest station in the first half of 2022, but the number climbed to 21% when data for the second half of 2022 was included, according to KBB. Customers reported software issues, vandalized chargers and payment processing problems as primary reasons for charging failures.

“We can’t add new chargers and let all those old ones fall into a state of disrepair,” Brent Gruber, executive director of global automotive at J.D. Power, told KBB. “We have to manage the maintenance of those as well because that’s the only way we’re going to meet the consumer demand.”