How long does an electric car battery last?

Modern lithium-ion packs degrade gradually rather than failing outright, and the observed rate across large fleet studies is roughly 1 to 2 percent of capacity per year, meaning a car might retain around 85 to 90 percent of its original range after a decade. Federal regulation requires manufacturers to warranty electric vehicle batteries for at least 8 years or 100,000 miles, with California requiring 10 years or 150,000 miles, and warranties typically guarantee against falling below 70 percent capacity. Actual replacement rates outside of specific recalled models have been low, which is a meaningfully better picture than the early-adoption anxiety suggested.

What accelerates degradation is worth knowing because most of it is controllable. Frequent DC fast charging generates heat and stresses cells more than slower home charging. Habitually charging to 100 percent and running down to near zero is harder on the chemistry than staying between roughly 20 and 80 percent, which is why many manufacturers set a default charge limit below full and recommend charging to 100 only before long trips. Sustained extreme heat is the biggest environmental factor, which is why packs in hot climates without active thermal management age faster. Newer lithium iron phosphate chemistry tolerates full charging better and generally cycles longer, at the cost of somewhat lower energy density.