Study on EV battery lifespan yields 'shocking' (positive) results

[voxel]

Real world data from a Tesla owner.

https://teslamotorsclub.com/tmc/threads/some-new-data-from-research-on-tesla-model-3-cells.311793

TLDR: Keep your SoC between 30-50% and there's no escaping calendar aging (battery degradation).

Also... live in colder climates. I saw another study that confirms this.

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[CrazyOne]

Is degradation the primary problem though? I always worry that one of the 7776 cells will go bad and decide to pull a fast fire on me.

 

[Whale Blubber]

Very illuminating. Really, an electrifying read. Nice to see an article offer some resistance to current EV reporting. Will be interested to see watt develops here.

 

[BigSkies]

Bear in mind that with time comes opportunity. If Rivian is even partially successful, there WILL be aftermarket (non-OEM) options. It just happens. Competition and all of that. And with EV/Battery/tech in general always finding its footing with time, the price of these items will be subject to competition.

And if EV mass adoption does take off (whether through legislation or natural selection), your local garages will have to adapt and will start to wrench on them. Or they'll go out of business and someone who will then takes their place.

Right to repair laws and Moss-Magnuson warranty (similar) acts will prevent Rivian from keeping everything in-house-proprietary forever. I think the second we start seeing R1s out of warranty who want to have someone else working on their vehicles, this will become a very real situation and Rivian will have to let go of their control.

Bottom line: time will tell, but I would anticipate, if nothing else, the costs of replacing or refurbishing/refabricating batteries will come down to more reasonable levels.

I think this will happen eventually as well, but I think companies like Tesla and Rivian will hold out as long as possible. Likely up to the point they're forced to settle a class action lawsuit from customers.

Both companies are building quite the service monopoly. It doesn't matter how much the parts cost, Tesla and Rivian can mostly charge whatever they want. Even if they can make a $20k battery, there's no reason they won't charge $50k. Particularly if that means a reasonable chance at a repeat customer buying a new vehicle.

Heck, Elon says a lot of dumb shit, so take it in context of the other dumb shit he says. But he did recently make a claim that they could dramatically cut their margins on new car sales and make it up on the service side of the business. There's at least a kernel of truth to this.

 

[emoore]

I'm pessimistic on having any real options to replace a battery unless it's under warranty. with the rate of change in battery technology it's going to be unlikely that there will be direct drop in placement batteries. It's like engines for cars these days, used to be able to change out an engine in older cars. Now its probably near impossible to put a non OEM engine in a modern car.

Cars are consumable items so after 20 years and 200k most people replace the entire car. I'd love to run my R1T to 200k miles and then use the battery for a house backup.

 

[A Land Rover Forever]

I can second that! My wife has an 8 year old BMW I3 for local driving and the battery is as good as it's ever been. Because it's a commuter it gets charged 4 times a week!

 

[mkhuffman]

Real world data from a Tesla owner.

https://teslamotorsclub.com/tmc/threads/some-new-data-from-research-on-tesla-model-3-cells.311793

TLDR: Keep your SoC between 30-50% and there's no escaping calendar aging (battery degradation).

Also... live in colder climates. I saw another study that confirms this.

And the money quote from the person who posted the data:
"I will not change any of my charging behavior because of this report. There is from time to time small differences in the reports and usually the reason for that can be found by thoroughly comparing with other tests. We need much more than one report to state a “fact”. "

 

[voxel]

And the money quote from the person who posted the data:
"I will not change any of my charging behavior because of this report. There is from time to time small differences in the reports and usually the reason for that can be found by thoroughly comparing with other tests. We need much more than one report to state a “fact”. "

Storage charge for lithium ion batteries is basically 40-50% SoC (3.8V per cell) which preserves the battery's life. This person's test just confirms hundreds of others.

I think you missed the best quote though:

"Tesla’s position seems to follow a theme...they combine best practice with ease of use. This advice is great for most owners usage"

Who wants to keep their EV from 30-60% SoC and never charge above 1C and never discharge over 1C (hard acceleration). That seems to be Toyota's MO with the bz4x and Solterra.

 

[Joe Hoffman]

I've owned a Ford CMAX plugin hybrid for 10+ years now with 93000 miles on it. 7.5k battery. It was awesome when it was new, but from todays standards people laugh. But it's still a great car, just less range. Of course original pure EV range was about 25 miles. 10+years later the range is 9 miles on pure EV. Go ahead, laugh. But don't compare it to EV standards but instead compare the lifetime MPG of 59. Can't beat that with any ICE vehicle on the road today.

Since it's only a small battery there's no sense in charging it only to 80%. It got charged to 100% every day of it's life. I estimate about 3500 cycles from 0-100%. Pretty harsh conditions and about 40% life still left in the battery. The 59mpg is today. When it was young and fresh I was getting 90-100MPG. Of course that depends a lot on your driving style/distance/etc before it switches to hybrid mode.

 

[flaky]

Sadly, I think that's the actual cost includign the labor.. idk where they got this $5-20k from, but that's far from the reality.

This is the source for $5-20k from article:
https://www.recurrentauto.com/research/costs-ev-battery-replacement

 

[Adventusaurus]

I've owned a Ford CMAX plugin hybrid for 10+ years now with 93000 miles on it. 7.5k battery. It was awesome when it was new, but from todays standards people laugh. But it's still a great car, just less range. Of course original pure EV range was about 25 miles. 10+years later the range is 9 miles on pure EV. Go ahead, laugh. But don't compare it to EV standards but instead compare the lifetime MPG of 59. Can't beat that with any ICE vehicle on the road today.

Since it's only a small battery there's no sense in charging it only to 80%. It got charged to 100% every day of it's life. I estimate about 3500 cycles from 0-100%. Pretty harsh conditions and about 40% life still left in the battery. The 59mpg is today. When it was young and fresh I was getting 90-100MPG. Of course that depends a lot on your driving style/distance/etc before it switches to hybrid mode.

I had a 10 year old Ford Fusion Energi with about 100k miles and the battery capacity was about half also; I calculated based on charge times. I understand no liquid cooling on those batteries, which didn’t help, but yeah they basically get a full cycle every day for most owners, so roughly 5-7x more cycles per unit time than a full EV.

 

[Supratachophobia]

This is an interesting study on EV battery life. Granted there is not a lot of EVs on the road to get real long term numbers but this should help people concerned about premature wear.

Researchers make surprising discovery about lifespan of EV batteries: ‘That was a shock’

https://www.yahoo.com/news/researchers-surprising-discovery-lifespan-ev-110000330.html

"You'll never believe this clickbait heading!"

Might as well give us a TLDR; but my guess is that it's not a deep-dive into anything if it's coming from Yahoo News.....

 

[RedRaiderRivian]

What is less positive is the aging that happens with time. The same recurrent database indicates that vehicles are losing ~8-10% of their capacity in the first six years regardless of mileage. OTOH, it seems to level off after 10% and the decline gets extremely slow. But the only vehicles on the road for ten years at this point are a handful of Model S from Tesla (and some poj Leafs that do not count because of their terrible battery design).
[/QUQUOTE
I can confirm that the Nissan Leaf battery is subject to serious degradation in the Texas heat. I pretty much only charge on a 120v charger and this summer saw a huge decline in capacity. I am about to initiate a warranty claim as the vehicle is 7 years old and has 59k miles. Air cooled batteries are not going to last in south Texas.

 

[emoore]

I had a 10 year old Ford Fusion Energi with about 100k miles and the battery capacity was about half also; I calculated based on charge times. I understand no liquid cooling on those batteries, which didn’t help, but yeah they basically get a full cycle every day for most owners, so roughly 5-7x more cycles per unit time than a full EV.

No liquid cooling really kills the battery capacity. Just ask the first gen Nissan leaf owners.

 

[TexasBob]

I had a 10 year old Ford Fusion Energi with about 100k miles and the battery capacity was about half also; I calculated based on charge times. I understand no liquid cooling on those batteries, which didn’t help, but yeah they basically get a full cycle every day for most owners, so roughly 5-7x more cycles per unit time than a full EV.

This is a key point people fail to understand about PHEVs. You can easily run through 300 cycles a year on a PHEV without even thinking about it and with 10k miles a year. Even when OEMs put a lot of buffer on the battery (e.g. Volt, Fusion, etc.) that will degrade much faster. By contrast, 300 cycles on a Rivian ~ 90,000 miles.

As pointed out above, replacing a battery gets expensive quickly because of mark-ups, labor, etc. (Of course, no one will replace a PHEV battery for degradation, they just drive it like an overweight hybrid.)

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