If you drive an electric car, it’s natural for you to have some questions about your battery. How long will it last? What’s the best way to recharge it? What can you do to extend its lifetime? Frankly, few of us understand very much about batteries. All we know is when they fail, everything stops.
Part of the reason people worry is because there have been many issues with the batteries in cellphones and laptop computers, forcing people to go out and buy new ones after a few years of use. Then there was the problem Nissan had with batteries that failed in some of its early LEAF electric cars. And don’t forget about the agitators and naysayers who natter on ad nauseum in the press and on social media about all the things that are wrong with EVs.
So, if you have questions and concerns about electric car batteries, you’re not alone. The folks at Wired decided to have a chat with Qichao Hu, a graduate of Harvard and MIT who is the CEO of SES, a battery research company focused on the development of lithium metal batteries and artificial intelligence systems to better monitor the health of batteries.
Hu explained there are two types of batteries commonly in use today in electric vehicles — lithium iron phosphate (LFP) and nickel cobalt manganese (NMC). LFP batteries are less expensive — particularly now when the price of nickel and manganese have skyrocketed — and tend to have a longer useful life. NMC batteries, however, have a higher energy density and are the preferred choice for cars with higher performance expectations.
Questions & Answers About Electric Car Batteries
We like to think all batteries have pretty much the same useful life, but Hu told Wired the same battery can have a completely different life span or level of performance depending on the vehicle it is used in. “Different cars in different designs, different price ranges, different users and behaviors … it’s hard to say one car is better than the other car because of all these factors. From the battery perspective, it’s really just those two camps, nickel-free LFP or high-nickel NCM.”
Wired asked Hu if it is possible to overcharge the battery in an electric car. “Yes, absolutely,” he said. “Definitely across the board you don’t want to fully charge it or fully deplete it. You want to avoid below 10 percent and more than 90 percent. You don’t want to go from fully charged to fully empty.” This is where AI plays a role. Unlike cell phones, EVs constantly monitor their batteries to control charging and battery degradation.
Hu also said not only does charging an electric car in frigid weather shorten battery life, it can actually damage it. He suggests driving around to warm up first instead of charging your vehicle from a completely cold state. Many manufacturers — primarily Tesla — use a portion of the energy stored in the battery to keep it warm, which reduces the negative impact of charging in cold weather.
He added that the cold can also have a big impact on how far a car can drive before it needs to be recharged. Hu said he can drive 300 miles in his Tesla Model 3 at 70 mph, but if it’s cold and he increases his speed to 80 mph, range drops to around 170 miles. “At high power and low temperature, the amount of a (battery) capacity is much lower.”
A frequent question electric car owners have is whether frequent charging is bad for their batteries. Hu told Wired that owners shouldn’t worry too much about the number of times a rechargeable battery can be charged and depleted in its life span. He explained that manufacturers adjust the way the car utilizes its battery as the vehicle ages, “based on the time, the temperature, your driving behavior; it’s all done automatically by the software,” Hu says. His company is one of the major suppliers of such battery monitoring software.
The process, he says, is happening constantly on most EVs, with battery health data sent anonymously back to a central analysis system. The system determines if the battery is in good health or whether it is approaching a danger point and in need of healing protocols. “These danger modes can be detected a few weeks to months before catastrophic failure,” he said.
Does Tesla Have a Battery Advantage?
Tesla uses both LFP and NMC batteries to power its cars. It also spends lots of money on battery research. Hu says the advantage Tesla has over other car companies is that it makes its own batteries, whereas most other automakers do not. That gives Tesla “the advantage of data and software. You can collect data from the battery manufacturing and once the battery is installed in cars. If you think of a battery as a person, you have data from before birth to after birth, how it ages and grows up.”
Hu said all that data allows Tesla to build models that predict safety issues and track a car’s carbon footprint, which is needed to meet regulations in some countries.
When Will The Next Electric Car Battery Breakthrough Occur?
Hu said large scale battery innovations only happen about every 30 years. He expects the next major disruption in electric car battery technology to occur very shortly. His company is heavily involved in researching lithium metal batteries. They are similar to today’s lithium-ion batteries but will have “higher intensity, higher range, and lower cost.” He thinks AI and other technologies will also improve the batteries themselves, while increasing performance and safety. “I think it’s a combination of new hardware breakthroughs and software,” he said.
Finally, Hu claimed the cost of batteries is likely to fall with increased recycling of the raw materials used to manufacture them, such as lithium, cobalt, and copper. Ford and Volvo, for instance, recently joined a program to begin EV battery recycling in partnership with Redwood Materials, a battery recycling company started by former Tesla chief technology officer JB Straubel.
“In the future, you can think of the car as the mine. We’ll be less dependent on whatever happens with global raw material price.” That’s an important consideration, considering the price of nickel has more than doubled in the past month.
People are naturally jittery about battery-electric cars. If there’s a problem with the battery, all you have is a nice bit of industrial sculpture in your garage or driveway. But all manufacturers warranty their batteries for at least 8 years and the results of now billions of miles of real world experience is that batteries have a far longer life than even the manufacturers ever expected.
Tesla is talking about “million mile” batteries, and CATL says it plans to beat even that goal. The bottom line is, electric cars are proving to be more reliable with longer useful lives than conventional cars powered by gasoline and diesel engines. The takeaway, then, is this: Drive an electric car. Be happy.
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