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EV Batteries Are Defying Expectations After Miles

wsj.com

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Re: EV Batteries Are Defying Expectations After Miles

#71

Post by dzhiurgis »

Taniwha wrote: post #51
Exoristos wrote: post #20

Earlier quoted context omitted.

Those old taxi Priuses have had their batteries replaced.

The original Prius batteries can easily have individual cells replaced (mine is 20 years old, we've replaced 2 cells) - of course Toyota want to sell you an entire battery, the wrecker will sell you a whole bunch of spares (do this with care, an entire pack is hundreds of volts)

Generally you can't replace cells unless you find perfect match - needs to be same resistance and capacity. Only on very large scale this is possible.

That said on most EVs blown cells are very very very rare. Mostly it's balancing lead that looses contact.

Re: EV Batteries Are Defying Expectations After Miles

#72

Post by rsync »

PaulKeeble wrote: post #5

No manufacturer is testing the batteries life by just charging and discharging them daily for a decade before releasing them. Instead they are using artificial acceleration techniques like getting the battery hot while charging/discharging continuously to simulate a longer lifetime. They can't realistically do anything else to estimate it. But it turns out heat is the big enemy for li-ion batteries and if you can kee…

“They can't realistically do anything else to estimate it …”

Of course they can.

How do you think they get the MTBF for hard drives?

What they do is deploy thousands of them and wait for the first one to fail. Then they wait for the second and third ones to fail… And then they can construct a statistical abstraction for the entire population based on the very first degradations … and that doesn’t take long at all.

Re: EV Batteries Are Defying Expectations After Miles

#73

Post by d12bb »

Theodores wrote: post #54
raychis wrote: post #31

EV batteries may be lasting far longer than most buyers expected but are consumers really going to trust the data over the headlines? There has been such a propaganda attack on EVs that it will take a long time to overcome that.

Although I have had rechargeable batteries in gadgets for decades, I would not like to have an EV parked in a garage beneath my bedroom, juicing up with many kilowatts, every night. No amount of fire exits would help, I mean, what about my stuff?!? No amount of insurance would cover personal belongings that could get lost, so that means stress from the stupid EV. The technology might be generally proven (the EV could…

I hope you do not have an ice vehicle parked in your house currently, as these tend to burn much more often…

Re: EV Batteries Are Defying Expectations After Miles

#74

Post by thebruce87m »

Theodores wrote: post #54
raychis wrote: post #31

EV batteries may be lasting far longer than most buyers expected but are consumers really going to trust the data over the headlines? There has been such a propaganda attack on EVs that it will take a long time to overcome that.

Although I have had rechargeable batteries in gadgets for decades, I would not like to have an EV parked in a garage beneath my bedroom, juicing up with many kilowatts, every night. No amount of fire exits would help, I mean, what about my stuff?!? No amount of insurance would cover personal belongings that could get lost, so that means stress from the stupid EV. The technology might be generally proven (the EV could…

You are aware that there are multiple different chemistries, right? Go look at people drilling into LFP batteries on YouTube.

ICE cars are not immune to fires either - there are lots of recalls due to faults in the 12V systems causing fires even when parked.

Re: EV Batteries Are Defying Expectations After Miles

#75

Post by Tadpole9181 »

rsync wrote: post #72
PaulKeeble wrote: post #5

No manufacturer is testing the batteries life by just charging and discharging them daily for a decade before releasing them. Instead they are using artificial acceleration techniques like getting the battery hot while charging/discharging continuously to simulate a longer lifetime. They can't realistically do anything else to estimate it. But it turns out heat is the big enemy for li-ion batteries and if you can kee…

“They can't realistically do anything else to estimate it …” Of course they can. How do you think they get the MTBF for hard drives? What they do is deploy thousands of them and wait for the first one to fail. Then they wait for the second and third ones to fail… And then they can construct a statistical abstraction for the entire population based on the very first degradations … and that doesn’t take long at all.

If they want to avoid confounding variables to real world use, this could take years. Nobody wants to wait years after an innovation to sell their product, so they develop ways to speed up the testing and get a number.

A machine that presses a keyboard switch 500 times a second for several days straight is obviously not indicative of someone actually using the keyboard. But it'll get the "absolutely beat the snot out of it" number, which is usually good enough for marketing.

Re: EV Batteries Are Defying Expectations After Miles

#76

Post by apparent »

> When early EVs hit the market, buyers’ concerns were well-founded. Roughly one in 12 EVs built from 2011 to 2016 have had to have battery replacements. But new data shows that more modern EVs are doing better so far. Among EVs built from 2022 on, 0.3% have had battery replacements, according to a 2025 study from Recurrent.

This is kind of a dumb comparison. It would be more useful to know how many vehicles had to have replacements within X years of being put in service. Obviously newer vehicles are much less likely to have needed a replacement at this point in time.

Re: EV Batteries Are Defying Expectations After Miles

#77

Post by apparent »

> EV batteries aren’t without their challenges, though. A battery that is frequently fast-charged with high power loses its range, on average, at twice the rate of a battery charged at a lower power, according to telematics company Geotab.

I wish my car could charge at different rates depending on whether I'm going to need to use it again soon. If not, it could trickle charge and be full enough by the next morning.

Re: EV Batteries Are Defying Expectations After Miles

#78

Post by cgyvbunji »

defrost wrote: post #66
foxglacier wrote: post #64

Earlier quoted context omitted.

Do you mean 11 years is a "long" time? I'd say it doesn't matter how long it was - it ended up better the expected based on the miles, and since it was a high-mileage-per-year car, that supports the claim that degradation is determined (at least more than expected) by calendar years, as cgyv.. claimed. I don't see how it doesn't support his claim.

It's all moot speculation in the absence of any firm notation of what cgyvbunji considers "calendar age based degradation" to be.

The battery industry defines calendar age degradation, not a random guy on the Internet like me. It's like saying you can't discuss voltage without me defining what voltage is.

Re: EV Batteries Are Defying Expectations After Miles

#79

Post by cgyvbunji »

foxglacier wrote: post #65
imtringued wrote: post #24

Earlier quoted context omitted.

So according to you, the more you degrade the battery, the longer it lasts? Usually you would think that 25000 miles per year over 11 years would degrade the battery faster than the car just sitting around for 11 years.

According to cygv... the more intensely you use the battery, the more miles you get out of it, so kind of yea, the faster you use it, the "longer" it lasts in miles. And this example supports that idea because it was used more intensely than usual and lasted more miles than usual.

Yes, exactly, as long as you don't fast charge. The ideal scenario for TCO measured as dollars per mile driven should be driving every day until you are down to some threshold, slow charging overnight, and repeating that each day until it's a brick. Should end up with something like 200-300k miles that way.

Re: EV Batteries Are Defying Expectations After Miles

#80

Post by beAbU »

apparent wrote: post #77

> EV batteries aren’t without their challenges, though. A battery that is frequently fast-charged with high power loses its range, on average, at twice the rate of a battery charged at a lower power, according to telematics company Geotab. I wish my car could charge at different rates depending on whether I'm going to need to use it again soon. If not, it could trickle charge and be full enough by the next morning.

Does you EV not have a charge rate setting for AC charging?

Or do you want such a feature when DC charging?

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