Extend your EV battery’s lifespan with two simple steps

Here’s a question for anyone thinking of buying an EV: How long will the battery last?

Short answer: longer than most EV buyers will own their vehicles.

While battery degradation is inevitable, there are two important steps you can take to slow it down.

Anyone who’s kept a cell phone or laptop long enough knows that even the trustiest rechargeable battery gives up the ghost eventually. Over time, battery cells lose the ability to hold as much charge as when they were brand-new.

Battery life

So exactly how long do electric car batteries last, and what steps can you take to slow the degradation?

Much like those in a phone or laptop, electric car batteries are lithium-ion and made of a variety of rare-earth minerals like cobalt, nickel, cadmium, and manganese plus other materials. Every battery, regardless of what vehicle it’s in, will experience degradation over time.

Even your location’s weather can affect the longevity of a battery. Extremely hot and extremely cold environments, as well as those with excess humidity, can shorten a battery’s lifespan.

Lithium-ion batteries have a high-energy density compared to the lead-acid batteries or nickel-metal hydride batteries found in hybrids. They also charge up quickly and are able to retain their energy density over hundreds of charging cycles. That’s why they’re the ideal choice for electric vehicles right now. The introduction of solid-state batteries may change that soon, but for now, lithium-ion is the best option for EVs.

But every charge and discharge cycle fractionally reduces a battery’s overall capacity. Over the course of hundreds or even thousands of charging cycles, a vehicle’s range eventually takes a hit.

Range decline

A 2019 analysis sampled data from 6,300 electric cars and found the average rate of range decline for a battery is about 2.3% per year.

In real-world terms, that means that if you have an EV with 300 miles of range, as so many do now, in five years, you can expect to have a maximum range of 267 miles due to battery degradation. Of course, it takes forever to get a 100% charge, so most people charge to 80% to get back on the road.

Every manufacturer has different projections for how long its batteries will last, but the U.S. Department of Energy has made its own predictions.

According to the DOE, “Predictive modeling by the National Renewable Energy Laboratory indicates that today’s batteries may last 12 to 15 years in moderate climates,” while those who live in “extreme climates” can expect those numbers to be in the eight- to 12-year range.

As we don’t have as much real-world data yet, this is largely speculative. The average vehicle on American roads right now is more than 12 years old.

What about your car’s EV battery warranty?

The federal government mandates that EV manufacturers offer at least an eight-year/100,000-mile warranty on all EV batteries. California ups that to a mandatory 10-year/150,000-mile warranty. Assuming the warranty is transferable, this could be a future concern for the fourth or fifth owner with 100,000 miles on a used vehicle.

What you can do

While battery degradation is inevitable, there are two important steps you can take to slow it down:

1. Avoid heavy acceleration and abrupt braking

Asking your battery to discharge energy rapidly over and over again essentially overworks it and causes it to degrade faster — it’s a lot like constantly leaving your phone screen on.

2. Maintain a charge between 20% and 80%

Charge your battery when it reaches 20% and charge it to 80%. Most cars allow you to set the specific parameters and can cut off charging at a certain value. This approach puts far less strain on the battery’s internal chemistry.