A new study published in Nature Energy has found a flaw in how EV battery longevity is tested. According to the study, the typical testing cycle used by researchers to estimate the lifespan of an EV battery underestimates the battery’s longevity compared to real-world, everyday use by a factor of about one-third.
Battery scientists typically test batteries by a constant rate of discharge followed by recharging. Repeating this cycle is how they estimate a battery’s life expectancy. However, the Nature Energy study found that this may provide an accurate lifespan prediction for commercial electric vehicles like buses and delivery vans but not for personal EVs used for everyday driving.
“We’ve not been testing EV batteries the right way,” said Simona Onori, senior author and an associate professor of energy science and engineering at the Stanford Doerr School of Sustainability. “To our surprise, real driving with frequent acceleration, braking that charges the batteries a bit, stopping to pop into a store, and letting the batteries rest for hours at a time helps batteries last longer than we had thought based on industry-standard lab tests.”
The researchers who conducted the study designed four discharge profiles. One was the constant discharge model typically used in such testing, and the other three were a mix of discharge profiles intended to mimic real-world use. To the researchers’ pleasant surprise, EV life expectancy climbed in the discharge profiles that imitate stop-and-go traffic and periodic rest.
In other words, driving your EV in regular city traffic, letting the battery rest while you’re at work, a grocery store, or a restaurant, and driving it back home in traffic is actually good for the battery pack.
“We battery engineers have assumed that cycle aging is much more important than time-induced aging. That’s mostly true for commercial EVs like buses and delivery vans that are almost always either in use or being recharged,” said Geslin. “For consumers using their EVs to get to work, pick up their kids, go to the grocery store, but mostly not using them or even charging them, time becomes the predominant cause of aging over cycling.”
This is good news for existing and future electric vehicle owners who might be concerned about their cars’ longevity. These findings, along with the recent Recurrent study that predicted batteries will be cheaper to replace than gas engines by 2030, could help smooth the transition to a more electrified car market.
Comments
They’re getting better. Atleast with personal electronics. But some still have degradation issues it seems.
I had a Samsung flip phone in my college days and after two years I could only get a 20 min phone call on a full charge. My 7 year old Macbook Air now also doesn’t hold a full charge and while not as bad as my last MacBook where after 8 years it could only hold 5 minutes of battery power, its still degraded where at most I get a little over an hour of charge. And keep in mind, these electronics are in stable room temperature conditions.
On the flip side, my 6 year old work iPhone 11 has been holding pretty well and I use this phone hard for work and Pandora. So there is some hope here but the fact of the matter is, I still have a full range on a full tank of gas on my 9 year old Rav4. So until degradation is a thing of the past I cannot confidently buy an EV.
Even gas mileage reduces over time. It’s just not as noticeable. As the story said, EV batteries are tested more like cell phone batteries. Charge to 100% and then discharge to ~0%. You can’t do either in the real world because you’ll never fully charge or discharge the battery. Buffers are built in. On top of that, unless you’re pushing your car to the next charging station, it’s not at 0%. On top of that, most owners don’t charge to 100% because you don’t need to have 200-300+ miles available to you daily.
The net result is EV batteries will last long past the car’s life.
BrO, most vehicles I’ve seen get better gas milage with age, as the cylinders wear a smooth coating and bearings find their sweet spot, and their tires get replaced with the latest and greatest compounds. Biggest hit to GAS economy has been Ethanol blends.
That said, idk any EV that has a sign posted on the window that tells you when to replace the battery, and in fact, lots of self proclaimed experts are squawking that EV batteries last the life of the vehicle despite endless news articles of individuals who are having to replace their batteries, even though their doing this “stepped discharge” nature magazine is talking about, also, do we really think Nature magazine isn’t biased? Just another Soyburger on the nothing burger of EV’s. In real news, anyone see Hertz is selling Tesla’s for under 20K cause nobody wants them?
Endless news articles…lol, I guess 2 or 3 is endless in your mind. As far as Hertz unloading their EV’s, after the “big disaster” in Chicago last winter when EV uneducated numbskulls rented them for use as Uber.
Of course sub-zero temperatures and lines at charging stations has them all crying because it was costing them more than what they could make on fares.
No one who has the ability to charge at home had a problem charging.
Those who can charge at home may not have a problem. Unfortunately for the EV delusionals that refuse to see reality and think those that don’t live in standalone homes can be considered irrelevant, 38% of Americans live in apartments and will not have that luxury. So whether you or the automakers like it or not, this is too large a market to ignore and blow off. They need to get better at charging. There’s no way around it
You can live in an apartment and still have EV chargers in it, like I do. So having a standalone house is not strictly required. Admittedly EV chargers at apartments are still quite rare tho. And my landlord is shaking me out for $0.50/kWh for a slow-ass 6 kW charge, but that’s a different story.
How about more like 20-30 news articles. And we’re talking battery replacement before the vehicle rusts out numskull. Not freezing batteries.
Funnily I am actually trying this tactic out on my current Galaxy S22. It has a setting that lets you limit the full charge to 80%. I also remember a Tesla salesman tell me this is a recommended charge pattern.
In other words if you want your EV batteries to last longer don’t drive your vehicle.
In other words, if you don’t live too long, your car will last for the rest of your life.
If the smog doesn’t kill you the pollution from the battery refining process will. Luckily this is happening in a country whose government sees its people as disposable assets. So pick your poison (pun intended).
In other words, learn to read with comprehension, Dirty Joe.
I did moron, the article stated “let the batteries rest and they will last longer”. That means don’t drive the vehicle, whether inconvenient or not, and your batteries will last longer.
I’ll give them 10 more years to get it right.
Gas engines burnt and dripped oil so bad that virtually all owners check oil at every fill up and after 60 or so years they painted the dip stick yellow so that once or so a year that an owner checked oil they could find it. Gas engines today develop more horsepower, burn less fuel and cause less harmful gases this only took over 100 years. Give alternate fuels a chance.
We have….. For over 100 years. FYI,
-stanlry steamer
-buick Electric cart
-olds battery wagon
-opel blitz wood burner
-70’s water car
-GM EV1.
What’s new is old and old is new. Same song, different verse. Chin@s p0litical war against oil has put a freeze on ice development since early 2K, and despite the fact we have plenty of concept engines with 30% or greater efficiency, the sellout deepstate EPA wants us to buy batteries from china so we’re are in ICE limbo while batteries get big brother money. Let’s see how EV’s hold out when new ICE engines get approved and the gravy train to Chin@ stops.
Steve, you did it again. To state so convincingly that EPA is working hand in hand with China, to bring in their batteries in the USA is the craziest conspiration theory I heard in a while. Like EV believer said, “Give alternate fuels a chance” and stop spreading ridiculous information. You forgot to mention about “The Big Oil” lobbying against development of alternate energy sources.
Did what again?
Remind you dumb nuts about “10% for the big guy” immediately followed by the closing of ANWAR and 5$/ gallon average nationally vs 2.50 for the prior president? Even now the average despite massive readjusting is 3.50$/gallon. Could you be any more blind???
My 2012 Volt has just over 166K miles. Electric range is the same as the day I bought it.
Did you thank GM for pulling the plug on this vehicle. This vehicle had a very low advertising budget.
Since EV sales are sluggish, bring in Fake News to fool the public into buying them.
I trust a fart more than I trust this “study.”
I don’t believe a single word of this study.
The border is closed and Biden is sharp as a tack, and his staff can barely keep up with him. People aren’t stupid!
It might be less expensive to replace EV batteries than changing a gas engine but how often would U change a gas engine. ? If U maintain a gas engine properly U shouldn’t have to replace it.
These 1,500+ lbs. EV batteries costs $16,000+ part only, labor, shop fees and sales tax are extra.
Nice try….