This ex-rental Tesla had already lost 20% of its battery capacity by 122,000 miles.
Its battery health then dropped from 80% to 76% in a year, then only slipped to 75% over the next 14 months.
The test suggests that early EV battery degradation can slow dramatically rather than continue in a straight line.
Buying a rental car can be a gamble, regardless of what powers it, because people aren’t gentle with their rentals and cars can see a lot of abuse. This 2022 Tesla Model 3 Long Range Dual Motor owner picked up the car when it was two years old, but its rough life as a Hertz rental left it with just 80% of its original battery capacity when they bought it in 2024, with the odometer reading 122,000 miles.
The owner, Fast Forward EV, then measured the degradation of its NMC battery pack once a year. After the first year, the remaining capacity had gone down another 4% to 76%. Now, when the test was performed again in May—14 months after the previous one—the battery had only lost an additional 1%, showing a state of health of 75%, with just shy of 156,000 miles.
