Do we need to worry about replacing expensive electric vehicle battery packs?

Replacing the battery pack of an electric vehicle

Electric vehicles have been on the market for about a decade, and owners may be wondering how long they will have to replace the vehicle's most expensive component: the battery pack. Potential buyers of used electric vehicles may have similar concerns: How long will the battery in the 2017 Tesla Model S I'm considering buying last?

All lithium-ion batteries, such as those in smartphones or laptops, degrade over time and use. So given the cost of a battery pack — a new one can cost $5,000 to $15,000 (32,000 to 95,000 yuan), depending on the vehicle — battery failure seems like a worthy concern.

On the other hand, it might not be worth worrying about. Here are 6 reasons why:

1. Car manufacturer warranty

Automakers offer extensive warranties on battery packs -- possibly longer than you plan to keep the vehicle. Tesla, which owns about 80% of the U.S. electric vehicle market, offers an eight-year/150,000-mile warranty on its Model S and Model X batteries for at least 70% battery capacity, meaning if the battery capacity drops below 70%, Tesla will replace it. The batteries on the Model 3 and Model Y Long Range and Performance variants are guaranteed for eight years/120,000 miles; Model 3 Standard Range batteries are guaranteed for eight years/100,000 miles.

Most EV manufacturers guarantee their batteries for 8 years/100,000 miles—and reports of EV battery failures are extremely rare. Still, if you're considering buying a new or used electric car, check the terms of the warranty. For example, some automakers will only replace a customer's battery if it fails completely.

2. The battery may last longer

Some evidence and studies suggest that electric vehicle battery packs can last well beyond 150,000 miles (241,402 km). Members of Tesla's online owner groups have reported less than 10% battery degradation after 150,000 miles, and Tesla CEO Elon Musk has said the Model 3 battery pack is designed to last 300,000 to 500,000 miles.

A 2019 study of 6,000 EV owners by Geotab, a Canadian software services company, found that electric vehicles lose only 2.3% of their battery capacity per year on average while maintaining "high levels of sustained health" over the long term. The study concluded that owners of newer electric vehicles with larger batteries won't need to replace them for 10 years or more.

3. Pushing for longer-lasting batteries

Since automakers know that durable batteries are key to widespread adoption of electric vehicles, there has been a quest in the auto industry to produce longer-lasting batteries. For example, Tesla and GM are reportedly working to produce batteries that can last for 1 million miles (1.61 million kilometers), while Chinese battery supplier CATL said it is ready to produce battery packs that can last for 16 years in 2020. Automakers and technology companies are also pursuing the development of solid-state batteries, the "holy grail" of battery technology.

4. Reduced production costs

The cost of producing electric vehicle batteries has fallen dramatically over the past decade. This trend is likely to continue, so even if electric vehicle owners must replace an out-of-warranty battery pack in the future, the cost may be more reasonable than it is today. In the future, it may be possible to replace only defective cells or modules in a battery pack, as Tesla does now, rather than the entire pack.

5. Competition between maintenance facilities

Independent competition to service electric vehicles is emerging. Some companies now produce cheaper refurbished replacement battery packs. Likewise, independent repair facilities have sprung up, such as Gruber Motors in Phoenix, Arizona; Electrification Garage in Seabrook, New Hampshire; Ocala, Florida; and West Palm Beach, Florida, where some companies specialize in electric vehicle battery pack replacement and other electric vehicle repair services.

6. Government assistance

Finally, the government might step in to help. California, for example, argues that people who buy used electric vehicles — as well as original owners of electric vehicles — should have confidence in the durability of what they’re buying. Proposed legislation would require electric vehicles to retain 80% of their certification test cycle range for 15 years or 150,000 miles, starting in 2026. It would also require owners to have easy access to the battery’s “state of health” and, like today’s hybrid batteries, warrant EV batteries for a 10-year/150,000-mile (241,402-kilometer) lifespan.

How to extend battery life

1. Don't fully charge your battery unless you're going to drive it right away. Most car manufacturers recommend charging to around 90%. Likewise, don't completely drain your battery. Keep it at at least 50% (or higher) whenever possible. Fully charging or completely draining your battery will shorten its life and may damage it.

2. Infrequently charge your electric vehicle at a DC fast charging station. Continuous use of a fast charging station for a long period of time will shorten the battery life.

3. If you live in an area with extreme temperatures, be aware that very cold weather can reduce the range of your electric vehicle, and very hot weather can shorten the battery life.

(Original source: American Automobile Association Global New Energy Vehicle Network, Global Lithium Battery Network, New Energy Network Comprehensive)