Life and Death of Li Ion batteries
Discussion
On a test of 350 Tesla's in the Netherlands and Belgium, battery degradation was at less than 10% after over 160,000 miles. The trend suggests that the average battery pack would cycle through over 186,000 miles before coming close to 90% capacity.
I tend to regard an ICE car as finished at 150,000 miles and happy to get rid for little cash.
Whilst some on here might want a vast mileage from their £5k Fiesta, some are not that bothered to be honest. 150k mileage is fine for me - and then I'll just buy another.
I tend to regard an ICE car as finished at 150,000 miles and happy to get rid for little cash.
Whilst some on here might want a vast mileage from their £5k Fiesta, some are not that bothered to be honest. 150k mileage is fine for me - and then I'll just buy another.
Merry said:
wormus said:
It’s commonly accepted that an EV battery needs replacing every 10 years or 100k miles.
Is it? For which chemistry? LFP is capable of many more cycles than NMC, for example. So it would hardly be a hard and fast rule. The answer on battery replacement is more like 'it depends'. Batteries do degrade, no doubt about it. We had a Mk1 Leaf so know all about that - but it strikes me as becoming less and less of a problem going forward, particularly taking into account the average miles someone in the UK would do.
As someone pointed out due to the size of some of these packs even 80% remaining capacity would still give you a pretty useful vehicle.
Clearly long range cars like Teslas are managing more than 100k miles.
LFP batteries are indeed good for many more cycles than most other chemistries.
But not many cars have LFP batteries.
With most cars it is going to be a combination of calendar aging and cycle aging.
LG make a battery or two.
Measurable degradation after only 40 weeks.
https://xebike.com/wp-content/uploads/2019/12/lg-e...
SpeckledJim said:
Hopeless isn't it.
Why doesn't he just stick to stuff that can't be argued, like 'I like brum brum noises' and 'I fancy the receptionist at the garage' and 'I like the pretty patterns oil makes in the puddles on my drive'.
See my earlier response “the nasty troll made my brain hurt!” Why doesn't he just stick to stuff that can't be argued, like 'I like brum brum noises' and 'I fancy the receptionist at the garage' and 'I like the pretty patterns oil makes in the puddles on my drive'.
wormus said:
Muzzer79 said:
OK, you really must be trolling now.
This old tripe again? Look back through the responses, and you’ll see some of the behaviour on this thread already is less than exemplary. Not my fault none of you can hold a healthy, intelligent debate.Well I really don't know what to say if that's the case.
Nomme de Plum said:
If the battery warranty is 8 years then manufactures will know that useable life will be much, much longer.
I've spec'd batteries in other industries.Depending on the consequences of a warranty 'failure', the average life might be anything from 20% to 100% more than the warranted life.
Statistics and all that.
If the failure consequence is somebody's 'uninterruptable power supply' only lasts 55 minutes instead of an hour and the have to fire up a generator, the battery maker faces a minor expense of giving the customer a nice discount on a new battery.
That will have a small margin on the life time spec.
If we're talking life support equipment and the consequence of falling short is death, law suits and corporate manslaughter charges, margins will be on the big side.
I think if your Ford EV loses too much capacity inside 8 years, they warrant to fix it back to 80% of nominal range or so, or in the limit that might have to buy back a handful of 6 year old cars or something. That side of it is easy, but the reputation damage of early failures would be taken seriously.
So, no doubt there is some margin in there. The average battery won't die before the mileage or time.
They can afford to be nice to 1% of failures or something and that sounds better than having a Range Rover.
But if the margins are as much as 50%, you won't want to be paying too much for the car once it's out of warranty.
OutInTheShed said:
Nomme de Plum said:
If the battery warranty is 8 years then manufactures will know that useable life will be much, much longer.
I've spec'd batteries in other industries.Depending on the consequences of a warranty 'failure', the average life might be anything from 20% to 100% more than the warranted life.
Statistics and all that.
If the failure consequence is somebody's 'uninterruptable power supply' only lasts 55 minutes instead of an hour and the have to fire up a generator, the battery maker faces a minor expense of giving the customer a nice discount on a new battery.
That will have a small margin on the life time spec.
If we're talking life support equipment and the consequence of falling short is death, law suits and corporate manslaughter charges, margins will be on the big side.
I think if your Ford EV loses too much capacity inside 8 years, they warrant to fix it back to 80% of nominal range or so, or in the limit that might have to buy back a handful of 6 year old cars or something. That side of it is easy, but the reputation damage of early failures would be taken seriously.
So, no doubt there is some margin in there. The average battery won't die before the mileage or time.
They can afford to be nice to 1% of failures or something and that sounds better than having a Range Rover.
But if the margins are as much as 50%, you won't want to be paying too much for the car once it's out of warranty.
A decade ago battery management systems were not quite as sophisticated as they are now yet my friend's BMW i3 is showing minimal battery degradation at 9 years. I'll ask her the actual though.
I know that is anecdotal so so really useful as data.
As to used values. I don't see these as following any different trajectory to those of ICE cars. Currently the numbers are skewed by lack of supply. It's not just cars though.
Currently if you are not comfortable then do not buy an EV.
Nomme de Plum said:
....
A decade ago battery management systems were not quite as sophisticated as they are now yet my friend's BMW i3 is showing minimal battery degradation at 9 years. I'll ask her the actual though.
.....
What the car chooses to tell her, and what might be measured under proper lab conditions might be two very different things.A decade ago battery management systems were not quite as sophisticated as they are now yet my friend's BMW i3 is showing minimal battery degradation at 9 years. I'll ask her the actual though.
.....
24 KWH LEAF : If the battery capacity level gauge of your 24 kWh Nissan Electric Vehicle falls below 9 bars (out of 12 bars) within 60,000 miles or the first 5 years of the vehicle’s life (whichever comes first), Nissan will repair or replace the damaged battery components free of charge to bring the capacity up to 9 bars.
ii. 30 KWH LEAF : If the battery capacity level gauge of your 30 kWh Nissan Electric Vehicle falls below 9 bars (out of 12 bars) within 100,000 miles or the first 8 years of the vehicle’s life (whichever comes first), Nissan will repair or replace the damaged battery components free of charge to bring the capacity up to 9 bars.
iii. 40 KWH LEAF : If the battery capacity level gauge of your 40 kWh Nissan Electric Vehicle falls below 9 bars (out of 12 bars) within 100,000 miles or the first 8 years of the vehicle’s life (whichever comes first), Nissan will repair or replace the damaged battery components free of charge to bring the capacity up to 9 bars.
I’ve got a 2015 24kw leaf on 56k miles. It’s on 11 bars out of 12 and 81% SOH.
ii. 30 KWH LEAF : If the battery capacity level gauge of your 30 kWh Nissan Electric Vehicle falls below 9 bars (out of 12 bars) within 100,000 miles or the first 8 years of the vehicle’s life (whichever comes first), Nissan will repair or replace the damaged battery components free of charge to bring the capacity up to 9 bars.
iii. 40 KWH LEAF : If the battery capacity level gauge of your 40 kWh Nissan Electric Vehicle falls below 9 bars (out of 12 bars) within 100,000 miles or the first 8 years of the vehicle’s life (whichever comes first), Nissan will repair or replace the damaged battery components free of charge to bring the capacity up to 9 bars.
I’ve got a 2015 24kw leaf on 56k miles. It’s on 11 bars out of 12 and 81% SOH.
Earthdweller said:
Nomme de Plum said:
I buy my iPhones outright. We do not seem to be suffering the battery life/performance problem you allege.
So do I This is my 2 year old iPhone now, it has 80% capacity and it’s performance over the last 3 months has deteriorated massively to the point it won’t last a full day, my wife’s bought at the same time is even worse and literally lasts a couple of hours
It really don’t think the above example is unique at all, it’s worth reading the first paragraph below
You phone has zero battery management, it can't it has just one cell so it can't cycle cells discreetly. An EV has multiple cell clusters, when you 'fully charge', even to 100%, in reality it's kept a few back and it will keep track and make sure each cluster of cells in turn is cycled in the most efficient way possible in reaction to whatever the owners charging habits are.
If what I am saying is correct that would suggest there should soon be a load of decade + old EV's with spaceship miles that still have very respectable 80%+ battery capacity - and there are. It's early days of course as we're only just starting to see significant numbers of decade+ cars, but so far the evidence is that the degradation simply isn't what was feared in the early days. We also know that charge cycles and use is the biggest contributor to degradation, so we can partly ignore the age of the car and just look at mileage - and again we see that heavy annual mileage cars with 200+ miles are also holding up just fine.
I'm surprised this is still a thing that worries people and gets so many articles written about it tbh. There are endless new angles found as to why we should be worried about battery lifespan, but every single bit of real world evidence points to EV's very easily exceeding the typical lifespan and use of ICE cars - and that usage and lifespan has been reducing over the last decade anyway.
SWoll said:
OutInTheShed said:
What the car chooses to tell her, and what might be measured under proper lab conditions might be two very different things.
That's a rather lazy deflection. More likely it just doesn't suit your argument if we're being honest?It's not even an 'open' secret that many battery devices start off at something like 105% of nominal to give some margin, but only report 100%.
Also is the i3 one of the cars which when new doesn't fully charge, because that's best for battery life?
I think with the i3, you can delve into it and get calculated capacities in kWh?
But these have a fair error margin, because apparently the indication you get varies up and down several percent from day to day.
What a random 'merkin i3 owner said:
New user here. Love my 14 REX, aside from this battery degradation thing. Here's my story:
I got my car around this time last year. I'd get around 75 miles of range on battery-only power for the first 7-8 months of ownership. Then I never got more than 65 miles. Chalked it up to cooler temps in the fall and winter, no big deal. I always charge the car to full on my 220 charger. When the car is ta home, it's usually on the charger.
In January I started seeing 60 miles max per charge, and the weather was warmer. Read about "batt. kappa max" here on the forum and started tracking it. First entry in my spreadsheet is January 27th - 48 degrees Fahrenheit, 52 miles of range, batt kappa max at 13.8. By April by April 26th - 3 months later- I saw my range drop to around 52 miles (83 degrees, 50 miles range, 13.2 batt. kappa max). My low for a single charge was 44 miles. You can see as you red down the spreadsheet - 13.8, 13.6, 13.4, 13.3, 13.2. It's a pretty smooth decline..
According to my calculations I was at 70.2% battery capacity. Granted, batt. kappa max is an estimate, etc.. but it was trending down over a fairly short period of time. Falling off a cliff, really. To go from a consistent 75 miles to 55 miles TOPS in a year is unacceptable. Time to call the only people I know of that have the ability to look into this problem for me - the dealer.
This is where the story gets weird. The dealer is cagey about what info they'll give. I ask what they do in this situation, how they check capacity? They tell me they plug the car in and BMW looks at the car and tells them how to proceed. They then measure the capacity of the battery with their diagnostic software. Questions are answered with rambling non-answers. No real info for me. 6 days later I get the car back and magically I'm at 16.2 batt kappa max. The car says it has roughly the same range, but after a couple drives it goes up to 64 miles. Dealer says I had 77% capacity. Also says they'd be happy if I was at the threshold for a warranty claim as they'd love the work. Right.
Now, I'm happy they've returned some range to me. What I'm afraid of is owning a failing battery pack which my local dealer (or BMW corporate) has moved the "safety stops" on. I had a pack which according to the car (batt. kappa max) was at 70%. I have the same pack, which is now miraculously at 86%. Not only did the dealership not tell me that they got me more capacity, they didn't tell me how they test capacity or what parameters they check. Doesn't seem right (legal?) to engineer and sell a car with certain parameters built into how the main power source functions, and when it stops functioning in that way the manufacturer reengineers it.
I'm going to call the dealer and try to get some info. Just thought I'd share some real world experience here. There doesn't seem to be much out there.
Quick question and please accept my apologies if it’s really daft. When charging a car or any device with a failing battery does the act of doing so cost more to do than it should. By this I mean does the act of trying to put more energy into a knackered cell actually mean that if the car only has 80% usable battery the effort of charging it cost more than the actual 80% figure. A bit like pouring petrol into a tank with a hole in it that will only fill to 80%.
Hope that makes sense.
Hope that makes sense.
TheDeuce said:
It's completely different - you charge your iPhone every day, a typical driver in an EV will charge once per week = two years for your phone is 14 years for an EV.
You phone has zero battery management, it can't it has just one cell so it can't cycle cells discreetly. An EV has multiple cell clusters, when you 'fully charge', even to 100%, in reality it's kept a few back and it will keep track and make sure each cluster of cells in turn is cycled in the most efficient way possible in reaction to whatever the owners charging habits are.
Not just that but if you actually take care of your iPhone’s battery (not using it much below 20%, not regularly charging it above 80%) then you don’t wear it anywhere near as quickly.You phone has zero battery management, it can't it has just one cell so it can't cycle cells discreetly. An EV has multiple cell clusters, when you 'fully charge', even to 100%, in reality it's kept a few back and it will keep track and make sure each cluster of cells in turn is cycled in the most efficient way possible in reaction to whatever the owners charging habits are.
My iPhone 13 Pro Max is still at 100% battery capacity and it’s now 16 months old, charged daily.
My Tesla on the other hand is also rarely charged above 80% (twice in 12 months) and again rarely discharged beyond 20% (once, the day I collected it with minimal range), has supposedly lost 3%, with the majority of that being the first few months, the degradation curve has flattened off since. It’s been supercharged 3 times, and is typically AC charged once a week.
TheDeuce said:
It's completely different - you charge your iPhone every day, a typical driver in an EV will charge once per week = two years for your phone is 14 years for an EV.
Y....
Your phone may get charged more often, but a year is a year is a year.Y....
Also although I charge my phone most nights, it's rarely discharged very deeply.
It does take a kicking when I run GPS based apps, which can flatten it in a day's hiking.
As it happens, my current phone is rather more than two years old.
A battery, or each cell, is a bit of wet chemistry. As well as wearing out from use, the 'wrong' chemical reactions happen over time.
That's pretty true for every flavour of battery, from Alkaline through lead acid to zinc carbon.
The LiFePO4 batteries which are favourite for home power storage are promising a lot more cycles than 'traditional' lithium, but feel free to point out any offering a decent warranty more than 10 years.
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