Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health

[Candleflame]

the issue is that battery replacement is just really expensive. not just the battery itself, but also the labour to replace it on the 3.
Which is frustrating given how heavily the 3 degrades.

 

[MaxRSM]

the issue is that battery replacement is just really expensive. not just the battery itself, but also the labour to replace it on the 3.
Which is frustrating given how heavily the 3 degrades.

My model 3 have lost 78.8 - 69.6 = 9.2 Kwh in less than 2 years.
It's loosing 0.4 Kwh every month , so in 5 years it could reach the 70% threshold.
I'm doing nothing wrong, charged 100% only twice, i live in North Italy, so not extreme temps.
Car is parked always in garage , both at home and at work.
My normal charging is up to 60-65%, down to 40-45%, rinse and repeat, supercharged less than 300 kwh total.
I don't know if at this point is better to stop to babysitting the battery and do 100%-2% cycles to accelerate the degradation.

 

[Candleflame]

My model 3 have lost 78.8 - 69.6 = 9.2 Kwh in less than 2 years.
It's loosing 0.4 Kwh every month , so in 5 years it could reach the 70% threshold.
I'm doing nothing wrong, charged 100% only twice, i live in North Italy, so not extreme temps.
Car is parked always in garage , both at home and at work.
My normal charging is up to 60-65%, down to 40-45%, rinse and repeat, supercharged less than 300 kwh total.
I don't know if at this point is better to stop to babysitting the battery and do 100%-2% cycles to accelerate the degradation.

im kinda in the same situation as you... not sure what to suggest. I got a bit more degradation than you but at this point in time I am not sure if i shouldnt just let the car sit at 85% or 90% to accelerate degradation so i hit the treshold before the time is over.

Clearly a lot of it is battery lottery rather than anything else and a good battery will always be a good battery and a crappy battery will always be crappy. But you dont want to be stuck with 25% degradation after 7 years.

 

[derotam]

I know people are frustrated about the degradation curve on these batteries but that is what the technology is right now. There is a warranty and while you can hope to do better than what the warranty states, I think in this case people should just expect the warranty specs as the reality of what is going to happen. I think the biggest issue people have is that the degradation if front loaded in time, again, because that is how these batteries work. It's just the way it is.

What do you expect Tesla or anyone else to do? They will of course continue to work on the technology but everyone has to be realistic.

Those that are frustrated...what do you suggest as a "fix"?

 

[Candleflame]

I know people are frustrated about the degradation curve on these batteries but that is what the technology is right now. There is a warranty and while you can hope to do better than what the warranty states, I think in this case people should just expect the warranty specs as the reality of what is going to happen. I think the biggest issue people have is that the degradation if front loaded in time, again, because that is how these batteries work. It's just the way it is.

What do you expect Tesla or anyone else to do? They will of course continue to work on the technology but everyone has to be realistic.

Those that are frustrated...what do you suggest as a "fix"?

the issue is that tesla lies by telling us what great shape our batteries are in. 10% degradation after a year and 20k kms is not great shape. and also unfair when there are many model s drivers with 8% degradation after 400k kms. It was completely unexpected.

I live in Australia now and I rely on being able to cover around 370-380km between chargers. And I can essentially not do this now as on our rural roads I get around 360km from 100% to 0% on a country road. Would have never thought Id be sitting on 15% degradation after just 2 years.

If I would have been told about the heavy degradation the 3 would experience I would have bought a Model S.

The issue also does not get helped by Tesla being dishonest stating "just an estimate" "charge to 90% for a few weeks every day (which just makes the situation worse)" etc.

Our only hope is (and I really do hope) that Tesla has added some of their iron battery technology in the cobalt batteries that maybe Model 3 starts forming a protective film on cathode/anode which essentially minimizes degradation after the car has aged 4-5 years. Provided that the battery hasnt degradated too much by then. However, that is also a big **** you to people living in warm climates who experience much more degradation initially, when what they should be doing is buying second hand cars from the cold which already have this film and wont degrade further.

 

[WhiteWi]

Our LR 3 lost 20 miles of range in 2 years. Do I care? No I can easily make up those 20 by driving more efficiently. Or try to rebalance bms and get some of that range back.

 

[Andrew S75]

I’ve owned a Model 3 SR+ for about two years. Before that I owned a Model S75 for about two years. I purchased the S because I got sick of waiting for the 3 to arrive in Australia. When comparing degradation between 18650 cells in the S and 2170 cells in the 3 these two particular cars are quite useful. I have kept notes on range available versus mileage for both cars since new.

When new both cars displayed 384 km (240 miles) at 100%. My Model 3 has now done 30 000 km over about the same time period as my Model S. Both cars charged to 80% regularly, higher on road trips, and the Model S was supercharged more than my Model 3.

Over 30 000 km the Model S had about 5% degradation and over the same distance my Model 3 is sitting at about 10%. Like most owners I would like to see less degradation in my Model 3 but it is nothing I can’t deal with. Lifetime consumption in both cars was 177 Wh/km in the Model S and currently 132 Wh/km in the Model 3.

 

[derotam]

the issue is that tesla lies by telling us what great shape our batteries are in. 10% degradation after a year and 20k kms is not great shape. and also unfair when there are many model s drivers with 8% degradation after 400k kms. It was completely unexpected.

I live in Australia now and I rely on being able to cover around 370-380km between chargers. And I can essentially not do this now as on our rural roads I get around 360km from 100% to 0% on a country road. Would have never thought Id be sitting on 15% degradation after just 2 years.

If I would have been told about the heavy degradation the 3 would experience I would have bought a Model S.

The issue also does not get helped by Tesla being dishonest stating "just an estimate" "charge to 90% for a few weeks every day (which just makes the situation worse)" etc.

Our only hope is (and I really do hope) that Tesla has added some of their iron battery technology in the cobalt batteries that maybe Model 3 starts forming a protective film on cathode/anode which essentially minimizes degradation after the car has aged 4-5 years. Provided that the battery hasnt degradated too much by then. However, that is also a big **** you to people living in warm climates who experience much more degradation initially, when what they should be doing is buying second hand cars from the cold which already have this film and wont degrade further.

See now you are trying to make your frustration the basis of your opinion that Tesla is "lying". I feel for you, I really do, but Tesla never implied that the batteries were going to behave, degradation wise, is any other way than the simplistic greater than 70% retention after 8 years/120k(miles) according to the warranty. Do I believe that should publicize a degradation curve for the warranty, or at least a few more data points, yeah that would be great.

Another point I would like to make is that even if you got a Model S, depending on when and what version pack you got, chemistries changed. The previous 90kWh pack degraded twice as fast in the beginning as the 85kWh pack did. So while I understand you seeing some people say they have better batteries on the S, you aren't necessarily getting the whole picture.

We are still in the wild west for long range EV batteries. Getting prices down has to sacrifice something. If the model 3 battery was so much better, I would have thought that Tesla would have changed the Model S over to the 2170 cell but they didn't.

 

[MaxRSM]

, but Tesla never implied that the batteries were going to behave, degradation wise, is any other way than the simplistic greater than 70% retention after 8 years/120k(miles) according to the warranty.

In my case i'm not arguing that Tesla is lying.
I have bought the LR version cause in the worst case i could rely on a 50 Kwh battery after 8 years and continue to use the car as a second car even if with a reduced range.
But i'm worried the battery could fall well below the 70% threshold after the 8 year mark, at that point i'll have to buy a new battery at a 20K+ price or scrap the car.
So maybe it's better to have the battery to fail before the 8 years...

 

[Candleflame]

Our LR 3 lost 20 miles of range in 2 years. Do I care? No I can easily make up those 20 by driving more efficiently. Or try to rebalance bms and get some of that range back.

Rebalancing is for the most part a myth.

 

[GtiMart]

Rebalancing, as in adjusting voltages of various cells? I don't know if it gets unbalanced enough to make a difference. Helping the BMS come up with a better estimate for the current battery capacity, that I believe does something.

 

[Candleflame]

See now you are trying to make your frustration the basis of your opinion that Tesla is "lying". I feel for you, I really do, but Tesla never implied that the batteries were going to behave, degradation wise, is any other way than the simplistic greater than 70% retention after 8 years/120k(miles) according to the warranty. Do I believe that should publicize a degradation curve for the warranty, or at least a few more data points, yeah that would be great.

Another point I would like to make is that even if you got a Model S, depending on when and what version pack you got, chemistries changed. The previous 90kWh pack degraded twice as fast in the beginning as the 85kWh pack did. So while I understand you seeing some people say they have better batteries on the S, you aren't necessarily getting the whole picture.

We are still in the wild west for long range EV batteries. Getting prices down has to sacrifice something. If the model 3 battery was so much better, I would have thought that Tesla would have changed the Model S over to the 2170 cell but they didn't.

thays why regulations exist. it is false advertisement. if you buy a car with a 70L fueltank and after 1 year you only have 50L then that is improper advertisement.

 

[Candleflame]

Rebalancing, as in adjusting voltages of various cells? I don't know if it gets unbalanced enough to make a difference. Helping the BMS come up with a better estimate for the current battery capacity, that I believe does something.

it does work, you may get 0.5-1% but noone here is arguing about 1%, its about loosing i.e. 15%.

 

[GtiMart]

Right, I don't know if 10-15% is possible. First time I tried, without putting that much effort in it, augmented the BMS estimate by 4%. I fell back to my normal patterns and it crept back down slowly. My next attempt, even with less effort, brought back 2%. It's not scientific but I'm not alone with positive results after simply letting the car sleep at low SOCs sometimes and charging to 100% sometimes. I'm saying it can be more than 1% depending on how much you've been following your patterns of always staying within the same small SOC range.

 

[Candleflame]

Right, I don't know if 10-15% is possible. First time I tried, without putting that much effort in it, augmented the BMS estimate by 4%. I fell back to my normal patterns and it crept back down slowly. My next attempt, even with less effort, brought back 2%. It's not scientific but I'm not alone with positive results after simply letting the car sleep at low SOCs sometimes and charging to 100% sometimes. I'm saying it can be more than 1% depending on how much you've been following your patterns of always staying within the same small SOC range.

i think recalibration is more of a thing in colder weather where voltage fluctuations are more common.
My car sits frequently around 50-60% But I equally do a lot of road trips of >1000km where the car frequently does 90% to 1% or even 100% to 0% discharges. I usually never get an upcalibration.

Usually when I get home from my roadtrip (both ends) I let the car sit at 5% or 10% overnight. Never makes a difference.

 

[GtiMart]

Yeah, I don't know what are the perfect conditions that lead to the most BMS discrepancy. Where I live temperatures go from peaks of +30C in summer to -30C in the winter. I haven't been driving much so the car can spend months before I do a significant trip that lets me do these low and high SOC things. The times I tried it, the BMS adjustment was never immediate. It always took a few times low and at least once at 100% for the BMS to finally adjust.

Some of it might be voltage adjustment in separate cells. Separate from the estimate discrepancy, actual degradation certainly occurs. Maybe in your case it's all actual degradation. YMMV as they say.

 

[Candleflame]

Yeah, I don't know what are the perfect conditions that lead to the most BMS discrepancy. Where I live temperatures go from peaks of +30C in summer to -30C in the winter. I haven't been driving much so the car can spend months before I do a significant trip that lets me do these low and high SOC things. The times I tried it, the BMS adjustment was never immediate. It always took a few times low and at least once at 100% for the BMS to finally adjust.

Some of it might be voltage adjustment in separate cells. Separate from the estimate discrepancy, actual degradation certainly occurs. Maybe in your case it's all actual degradation. YMMV as they say.

I find that cars in America where you have scorching summers and freezing winters tend to always have rated km variance where in winter you often get 5% pseudodegradation, whereas thats much less of a thing in Australia/Europe.Certainly my range has never gone up, it always just goes down. but we dont get a winter here.

 

[derotam]

In my case i'm not arguing that Tesla is lying.
I have bought the LR version cause in the worst case i could rely on a 50 Kwh battery after 8 years and continue to use the car as a second car even if with a reduced range.
But i'm worried the battery could fall well below the 70% threshold after the 8 year mark, at that point i'll have to buy a new battery at a 20K+ price or scrap the car.
So maybe it's better to have the battery to fail before the 8 years...

Yes, the battery could go below 70% after 8 years, absolutely! Who said anything about it not? First of all, the warranty gets you to the 8 year 70% mark. After that, the battery could just die and you would be screwed but this goes to long term longevity statistics for people to look at later to decide whether they want to buy a specific vehicle and how long they would want to keep it before getting rid of it. Of course the battery is going to continue to degrade...just like an ice car engine or transmission will continue to wear out over time.

thays why regulations exist. it is false advertisement. if you buy a car with a 70L fueltank and after 1 year you only have 50L then that is improper advertisement.

That is like saying if a glass can hold 12 ounces when new but after a year it can only hold 6 ounces then it's false advertisement. Well maybe you are continuing to fill up the glass with sugar water and then letting the water evaporate. Of course the water volume capacity will diminish over time but that is not the manufacturers fault!

Tell me where the specific articulable false advertisement by Tesla is?

 

[derotam]

Rebalancing is for the most part a myth.

Rebalancing in terms of actual battery voltage differences causing an apparent degradation I agree is not really the issue...Now recalibration in terms of forcing the BMS to re-assess the SOC based on the battery voltages, that IS a thing and causes APPARENT but not actual degradation. Sometimes people interchange rebalancing and recalibration which can add some confusion.

Edit: Adjusted for rebalancing/recalibration confusion.

 

[WhiteWi]

Should have said recalibrate * my bad