EV efficiency and range stability

A lithium-ion battery is a fuel tank that slowly shrinks, not a switch that suddenly dies, and new data suggests the shrinkage is modest over five years. (insideevs.com) InsideEVs reported on April 24 that modern electric vehicles are keeping most of their usable driving range after three to five years, helped by battery-management software that limits how much of the pack drivers can actually use. (insideevs.com) That software acts like a buffer at the top and bottom of the pack, so the car can hide some early wear before it shows up on the dashboard as lost miles. Geotab said in September 2024 that average battery degradation across nearly 5,000 electric vehicles was 1.8% per year, down from 2.3% in its 2019 analysis. (geotab.com) Geotab’s 2024 study covered about 1.5 million days of telematics data from fleet and private vehicles, and it said the best-performing current models were degrading at about 1.0% annually. (geotab.com) Recurrent, which tracks used electric vehicles, said in January 2026 that it had logged more than 1 billion miles of driving and charging data from more than 50,000 vehicles. The company said many cars beat their Environmental Protection Agency range estimates when new and continue to do so for years. (recurrentauto.com) Recurrent also said modern electric vehicles have a battery replacement rate of 0.3%, a figure that cuts against one of the biggest fears in the used-electric market. (recurrentauto.com) The caveat is that battery aging is not uniform. The National Renewable Energy Laboratory’s battery-life modeling says degradation depends on heat, charging rate, state of charge, storage conditions, and how deeply the battery is cycled. (docs.nrel.gov) Geotab’s newer update, reported in early 2026 from a larger sample of more than 22,700 vehicles across 21 makes and models, put average degradation at 2.3% per year and linked the increase partly to heavier use of high-power fast charging. (theenergyst.com) Automakers still build in a large safety net for buyers. Tesla’s current battery and drive-unit warranty runs 8 years with mileage caps from 100,000 to 150,000 miles depending on model, and it guarantees at least 70% battery capacity over that period. (tesla.com) The result is that a five-year-old electric vehicle is increasingly being judged less like a gadget with a fading battery and more like a regular used car with a measurable service history. (insideevs.com)