How Long Do EV Batteries Last?
One of the most commonly-asked questions from potential electric car purchasers is how long their batteries will last. Almost everybody who has owned a smartphone has noticed how, after a couple of years, the battery doesn’t hold the same charge – leading to understandable concerns about whether EVs will behave similarly. You don’t want to invest tens of thousands of dollars into a new electric car only to discover that it will lose a lot of its range a few years later.
Thee most recently released data from Recurrent, a data-gathering company specializing in EV analytics, suggests that potential owners don’t have much to worry about. Recurrent’s latest study, focused on the top-selling Tesla Model 3 and Tesla Model Y, suggests that after four or five years, batteries will lose less than 10 percent of their battery capacity, even if they are regularly charged on Level 3 DC quick chargers.
Tesla Battery Degradation: Study
After gathering data from over 7,000 Model 3 owners and over 5,100 Model Y owners, with over 1.6 million data points, Recurrent found that, on average, the Model 3 lost about 8 percent of its range compared to new after 1,500 days, with and the Model Y lost about 6 percent of its range compared to new.
Interestingly, even when brand-new, Recurrent noted that both Tesla models only achieved just over 70 percent of their EPA-estimated range, suggesting that Tesla models’ range estimates are rather more ambitious than some other manufacturers (you can find a list of vehicles that get closest to their EPA ratings here). But the fact that they lose relatively little of their range and battery capacity after a few years should provide confidence to buyers considering an electric vehicle.
How Does an EV Battery Degrade?
What’s interesting is that Recurrent’s data, which tracks range and battery capacity over time by connecting to a vehicle’s telematics system, showed that the degradation of an EV’s battery isn’t linear. Indeed, Recurrent says that lab tests show that lithium-ion batteries, which are used in the majority of EVs, have an S-shaped degradation curve.
There is noticeable degradation over the first year and a half as the battery “settles in” to a steady state, after which a period of very slow, linear aging commences. In smartphone batteries, lab tests show that there can be a sharp decrease in battery life just before the battery dies – but the good news is that, at least so far, Recurrent’s data doesn’t show any EV has yet experienced that sharp decline.
In large part, that’s because electric car batteries are still relatively new technology; very few electric cars have been around long enough to really gauge what the long-term future is for their battery capacity. Aside from very early Nissan Leaf models, Recurrent’s data shows that even EVs that are close to a decade old, such as the original BMW i3, still retain strong range and battery capacity compared to new.
Warranties for EV Batteries
One way to gauge the expected lifespan of an electric car’s battery is by looking at the warranty its manufacturer offers. While most vehicles have a comprehensive warranty of three or four years, every manufacturer offers a battery warranty of at least 8 years or 100,000 miles; some manufacturers, like Hyundai, offer a 10-year warranty, and even guarantee minimum levels of capacity.
Strong warranties should provide buyers confidence that batteries, the largest and most expensive component of any electric vehicle, will last for a long time, with automakers offering support well past the typical gasoline vehicle’s warranty period. As battery technology continues to improve, it’s likely we’ll see even better performance over time, with batteries retaining more of their capacity and delivering better range over time.
What Happens When My EV Battery Dies?
Of course, when an EV battery does reach the end of its life, you could be in for major expense – much like an engine rebuild on a gasoline car could cost you thousands. Fortunately, most manufacturers now have procedures in place to repair EV batteries rather than replace them outright.
EV batteries, after all, consist of thousands of individual pouches or prismatic cells which are wired together in a large enclosure. Modern diagnostic systems can identify which pouches or cells are faulty, and with proper training, dealer technicians can disassemble the battery and replace those individual pieces – saving costs as well as reducing environmental impact. These days, battery repairs are mostly still performed under warranty, but it’s nice to know you won’t have to replace the whole battery in your EV if it starts to fail.
EV Battery Recycling
Beyond that, if the time does come where you have to replace an electric car’s battery completely, it can often be repurposed for a number of other uses. One of the coolest recycling ideas is turning it into a standalone power pack for your home – able to charge up from solar panels or using the cheapest overnight electricity and providing for your house’s electrical needs when electricity is the most expensive.
Depending on the size of the battery pack, and how much of it is still usable, a repurposed EV battery could power your home for three days or even more – a great additional benefit, after it’s provided a useful service life in a zero-emissions vehicle.
