Most of us have lots of experience with the batteries in phones, computers, and other gadgets. Batteries don’t last forever, and we sometimes have to replace them. It’s a fact of life. These days, it’s becoming more common to drive electric cars and the fundamental principle is the same. However, the battery pack in an EV is the most expensive part of the car, so its reliability and lifespan is a greater concern.
EV batteries generally have generous warranties. In the US, EV batteries are required by federal law to be covered for at least 8 years or 100,000 miles, whichever comes first. So, the financial exposure from the battery pack is reasonably limited. Even so, EV owners would like to know that their car’s battery pack is likely to last a long time.
Battery life is generally determined by laboratory tests involving repeated charge-discharge cycles over a relatively short period of time, as opposed to those cycles being spaced out over years.
A new study by Stanford University looked at battery performance under conditions much more like what would be experienced in the real world. Cars experience frequent acceleration, braking that charges the batteries a bit, lots of stops, periods of rest, and so forth. Nothing like just charging and discharging repeatedly.
The study found that today’s EV batteries may last up to 40% longer than expected. Real-world stop-and-go driving benefits batteries more than standard test conditions.
The cost of EV batteries continues to get lower all the time and it is likely to be quite a long time before one is likely to need a new battery assuming one even keeps the car long enough.
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Existing EV batteries may last up to 40% longer than expected
Photo, posted August 27, 2021, courtesy of Ron Frazier via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio
