How long will electric vehicle batteries last? Tesla’s Roadster could be a guide
The question of battery longevity does not have a simple solution. Many factors affect cycle life of a battery pack, most notably climate, charging habits, driving style, and battery chemistry, and all the tests in the world cannot exactly replicate how each individual driver will use the battery over the life of the vehicle. How long will your vehicle’s battery hold on before being reassigned to a solar system on someone’s roof?
One of the most important variables in battery longevity is temperature. In general, temperatures above 86 degrees F place great stress on the battery and speed up capacity loss. Vehicles that have a liquid-cooled battery, like the Chevrolet Volt or Tesla Model S, are less vulnerable to high-temperature effects as long as they are not parked in the blazing sun.
However, the Nissan LEAF may be notably susceptible to rapid degradation in extremely hot climates. The results of an Idaho National Laboratory study released in March found that the test LEAFs lost 22-26% of their initial capacity after just 40,000 miles. This is most attributable to two factors: the vehicles were tested in Pheonix, where the hot climate accelerated capacity decline; and the vehicles were discharged to less than 5% capacity twice per day.