8% degradation after 9k miles, wtf?

[Chewy986]

Hello everyone!

So, I read a lot about proper battery maintenance (or so I thought), but I’m sitting on 8% degradation after 5 months and 9k miles… which sounds like way higher than most people experience and is pretty worrisome.

I charge my battery to 80% everyday as soon as I get home from work. I drive about 80 miles round trip and use around 30% of the battery daily, so when I get home it’s around 50%. I have never charged it above 85% and have been down to 17% only once and very briefly. I charge with my 220v 50a garage plug. I have never supercharged.

Based on the above fact pattern I expected to be in really good shape, yet my results are so far sub par.

I did buy the acceleration boost but mostly drive on the highway and rarely use it. I typically cruise 70-80mph which may be part or the problem. I live in Houston which is a hot climate for the battery and I generally have the AC on pretty high. I suppose the hot environment mixed with AC load and 80mph cruising speed is a bit taxing but I haven’t heard much discussion on it.

Any advice on how I might curb this degradation? Did I get a lemon?

Today I read 57% battery yielding 170miles for a 298mi capacity (or about 8.5% degradation vs new). I drive a model Y LR which is quoted at 326mi new)

 

[CaptJaC]

How do you check battery degradation? I googled it and the only relevant post that came up was the suggestion of letting the battery run down to under 10% then charge it back to 100%. If that's the only authoritative way to do it, then I'll give it a try closer to 10K miles. I'm on 5K miles now after about 4 months of driving my MY. .....

I actually scheduled a service with Tesla, via the app of course, for this very topic with the hopes they would text me or call me to discuss it. They actually called me 10 days later and said to discharge it to 10% wait 1.5 hours then charge at home to 100% and wait 1.5 hours to drive. I should do this monthly to exercise the battery and the miles / % battery will go back up. He said the % battery / miles to empty are based on many variables such as temp, previous driving habits etc.. He went on to tell me that the 10 days since I requested the service were used to look at my history, charging habits, speeds driven etc. and the numbers / % are just a snapshot in time and they were well below average of other MYs. We have since done the 10%-100% and indeed the miles to empty went up 5.

 

[DanDi58]

I don't really care about any of this degradation stuff. I just charge it and drive it and don't worry about it. Maybe at some point I'll go through the process to recalibrate, but I doubt it. Did anyone worry about their ICE vehicle not getting the same gas mileage the older the car got? I didn't think so.

 

[whisperingshad]

My March 31 build didnt have the 82KW battery, at 11k now and i was as 326 or so up till a few weeks ago(maybe software update etc). Now like 316 or so. I have done some full charge to under 20 charges. I supercharge a few times a week and charge with a regular 120V at home daily, occasional 240v on my lunches. Car doesn't sleep much lately lol, might be the issue. Set it to % and forget it lol.

 

[jpy1980]

You can get a quick estimation of what the BMS thinks by opening the Tesla app, select charging, and then slide the charging limit all the way to the right. It will be display miles as a small number on the green portion of the battery, just don't forget and leave it there or it will charge to 100%. And as other have said, this value can be battery degradation, but is just more likely that the BMS needs to be recalculated.

You must be on an older version of the app as the new one doesn’t have that feature anymore.

 

[jpy1980]

Also since I display the percentage as opposed to the EPA mileage rating, all I do to figure out what my total mileage at 100% is:

Divide the current mileage left in the battery by the current percentage.

So right now my car says I have 200 miles of range at 67% so 200/.66 = ~303 miles at 100% for my 2021 MYP.

* I use the Watch for Tesla app which gives me my approximation of mileage since the official app doesn’t show the current mileage left if you’re in percentage mode.

 

[mangrove79]

I actually scheduled a service with Tesla, via the app of course, for this very topic with the hopes they would text me or call me to discuss it. They actually called me 10 days later and said to discharge it to 10% wait 1.5 hours then charge at home to 100% and wait 1.5 hours to drive. I should do this monthly to exercise the battery and the miles / % battery will go back up. He said the % battery / miles to empty are based on many variables such as temp, previous driving habits etc.. He went on to tell me that the 10 days since I requested the service were used to look at my history, charging habits, speeds driven etc. and the numbers / % are just a snapshot in time and they were well below average of other MYs. We have since done the 10%-100% and indeed the miles to empty went up 5.

Good to know, thanks!

@jpy1980, the new version of the app still shows the mileage under the charging icon when i slide the slider. mine says 231 miles when i slide it all the way, which is 5 miles below the original 236 mi for an LR MY of course. i guess if i get around to recalibrate, it might go back up? who knows.

 

[DanDi58]

Good to know, thanks!

@jpy1980, the new version of the app still shows the mileage under the charging icon when i slide the slider. mine says 231 miles when i slide it all the way, which is 5 miles below the original 236 mi for an LR MY of course. i guess if i get around to recalibrate, it might go back up? who knows.

It only does that if the car is set to miles, not percent. The slider will represent whatever method you're using to track range. Which should be percent.

 

[whisperingshad]

I actually scheduled a service with Tesla, via the app of course, for this very topic with the hopes they would text me or call me to discuss it. They actually called me 10 days later and said to discharge it to 10% wait 1.5 hours then charge at home to 100% and wait 1.5 hours to drive. I should do this monthly to exercise the battery and the miles / % battery will go back up. He said the % battery / miles to empty are based on many variables such as temp, previous driving habits etc.. He went on to tell me that the 10 days since I requested the service were used to look at my history, charging habits, speeds driven etc. and the numbers / % are just a snapshot in time and they were well below average of other MYs. We have since done the 10%-100% and indeed the miles to empty went up 5.

Would do this once i get a 240v at home lol

 

[LowlyOilBurner]

I have 42,000miles on my 2020 Y LR. Today, 100% showed 293miles. I charge to 90% everyday. I’m not upset about those numbers, I might try the deplete to 10%, charge to 100% thing spoken about earlier in this thread.

 

[kishkaru]

2021 MY LR here. Just over 5k miles, car is 9 months old. 299 mi range @ 100%, just measured today.
299 / 326 = 92%, or 8% degradation after 5k miles.

It's been steadily decreasing every few month from 326 (new) -> 312 -> 308 -> 299 (now). I've been using Teslamate to keep track of the degradation (unfortunately, not since brand new). But the trend is clear:

I already reached out to Tesla when degradation hit 5% (~308 mi) last month, and Tesla HQ at Fremont did remote diagnostics. They recommended to charge to 100% often and sleep often to let the BMS re-calibrate. They also just change to display % and don't worry about the miles. Finally, they also said the usual "it's just an estimate based on driving speed, temp, elevation, hvac, blah, blah", which I don't buy (e.g. it's a Guess-o-meter), but whatever.

I will create another Tesla service visit once the degradation hits > 10% (290 mi or less indicated at 100%). FYI, my car never sleeps due to Sentry Mode being on 24/7/365, so it is possible that the BMS is totally messed up. But unfortunately I can't charge to 100% often or let the car sleep because apartment dweller.

 

[v8eater]

The display shows what the BMS thinks your pack capacity is. Well, displayed in miles. The problem is, over time there is drift in pack voltages. I've read the BMS doesn't actually balance the pack below 90% charge. Attached is the data from my car, a 2019 M3. Essentially the same as pack as the Y. The blue line is my estimated range, the green is data from all the other M3's who use Teslafi. My estimated range went down to 276 miles at one point. I started charging to 90% just before my cross-country

trip. Notice the estimated range increased as I drove cross country.

 

[Threader]

I don't really care about any of this degradation stuff. I just charge it and drive it and don't worry about it. Maybe at some point I'll go through the process to recalibrate, but I doubt it. Did anyone worry about their ICE vehicle not getting the same gas mileage the older the car got? I didn't think so.

agreed. turn battery readout to %. forget about it. Enjoy. charge when needed. You all measure your tread depth of your tires daily to see if they are wearing out faster than expected?

 

[Fourdoor]

agreed. turn battery readout to %. forget about it. Enjoy. charge when needed. You all measure your tread depth of your tires daily to see if they are wearing out faster than expected?

LOL, I just had a guy back out of purchasing my Uberturbine wheels and tires because the date code on the tires showed that they were not "new" because they were produced in October of 2020. Apparently a new car should have tires that were produced in the same month the car was built rather than being purchased from a Pirelli warehouse. Guess I should have rejected the car back on Jun 29th when I took delivery for having "old" tires!

Keith

 

[thesmokingman]

LOL, I just had a guy back out of purchasing my Uberturbine wheels and tires because the date code on the tires showed that they were not "new" because they were produced in October of 2020. Apparently a new car should have tires that were produced in the same month the car was built rather than being purchased from a Pirelli warehouse. Guess I should have rejected the car back on Jun 29th when I took delivery for having "old" tires!

Keith

That is the whackiest thing I've ever read in regards to buying wheels. Tires can be shelved for up to five years...

 

[Fourdoor]

That is the whackiest thing I've ever read in regards to buying wheels. Tires can be shelved for up to five years...

I suspect that he is massively ignorant on the subject of tires, or he had some other reason to back out and used this as an excuse. If it was just ignorance I would have expected him to ask a question about the date code rather than implying that I am lying about how old they are when saying they came off the car I purchased June 29th.

He is now implying that the tire age isn't the primary reason he backed out of the sale... thus implying to other potential buyers that I am shady. Granted, I am making fun of him NOW, but I was nothing but polite to him up to the point where he suddenly backed out of the purchase with this lame excuse. I have asked moderators to remove his post since it will negatively affect my ability to sell the wheels and tires. I was very tempted to reply though, I can be a real asshole... but my for sale thread is not the best place to display that For example, he said my tires are a year older than his that are on his Gemini wheels... my tires are 11 months old... so his tires are negative one month old? I would bet that he hasn't actually looked at the date code on his current tires, and they are probably at least 6 months old, and a year old wouldn't surprise me.

Keith

 

[thesmokingman]

I suspect that he is massively ignorant on the subject of tires, or he had some other reason to back out and used this as an excuse. If it was just ignorance I would have expected him to ask a question about the date code rather than implying that I am lying about how old they are when saying they came off the car I purchased June 29th.

He is now implying that the tire age isn't the primary reason he backed out of the sale... thus implying to other potential buyers that I am shady. Granted, I am making fun of him NOW, but I was nothing but polite to him up to the point where he suddenly backed out of the purchase with this lame excuse. I have asked moderators to remove his post since it will negatively affect my ability to sell the wheels and tires. I was very tempted to reply though, I can be a real asshole... but my for sale thread is not the best place to display that For example, he said my tires are a year older than his that are on his Gemini wheels... my tires are 11 months old... so his tires are negative one month old? I would bet that he hasn't actually looked at the date code on his current tires, and they are probably at least 6 months old, and a year old wouldn't surprise me.

Keith

Yea, that is whacked. There's no accounting for idiots I guess. Even if you buy new tires there is no way to determine what the production date is prior to recieving them. Tires from Tirerack for ex. can be up to 5 years old or more.

Tirerack has a whole section on this.

The British Rubber Manufacturers Association (BRMA) recommended practice, issued June 2001, states, "BRMA members strongly recommend that unused tyres should not be put into service if they are over six years old and that all tyres should be replaced ten years from the date of their manufacture."

Our experience has been that when properly stored and cared for, most street tires have a useful life in service of between six to ten years.

How Old Should New Tire Be at Tire Rack

How Old Should New Tire Be found in: Do Tires Age? - Part 2 | Tire Rack, Do Tires Age? - Part 1 | Tire Rack, TireRack.com - About - Tech Center, How..

tires.tirerack.com

And then when we put this all into context, tires on a Tesla last 10K-20K miles so that is an expected use life of two years out of ten, lmao.

 

[Fourdoor]

Yea, that is whacked. There's no accounting for idiots I guess. Even if you buy new tires there is no way to determine what the production date is prior to recieving them. Tires from Tirerack for ex. can be up to 5 years old or more.

Tirerack has a whole section on this.

How Old Should New Tire Be at Tire Rack

How Old Should New Tire Be found in: Do Tires Age? - Part 2 | Tire Rack, Do Tires Age? - Part 1 | Tire Rack, TireRack.com - About - Tech Center, How..

tires.tirerack.com

And then when we put this all into context, tires on a Tesla last 10K-20K miles so that is an expected use life of two years out of ten, lmao.

Yup, he could have had my wheels and tires for fairly cheap (they are at 8/32 tread depth, 10/32 is the depth new) and they would have been worn out in 6 months to two years depending on his driving style. Instead he will pay much more for "new" tires that will be worn out in 6 months to two years depending on his driving style... it blows my mind that he is obsessed with an irrelevant tire manufacture date. Unless he plans to park the car and never drive it for the next decade, the tires will be worn out and replaced long before the six to ten year point where tires "age out".

Keith

 

[mswlogo]

Will give it a try this week and report back. Thank you much!

Don’t baby the battery so much. I charge to 100% half a dozen times. When you do, plan around leaving as soon as it’s ready. I also never hesitate to supercharge. I’ve only lost a few miles at 22k miles on my model X after 2 years. And only lost a few miles on Model 3 after 10k miles and 1 year. I don’t think losing 10% first year is normal. Hopefully most of your loss is poor calibration.

 

[brkaus]

If you have FSD, definitely turn off summon standby. It keeps the car from sleeping.

 

[AAKEE]

So, I read a lot about proper battery maintenance (or so I thought), but I’m sitting on 8% degradation after 5 months and 9k miles… which sounds like way higher than most people experience and is pretty worrisome.

I charge my battery to 80% everyday as soon as I get home from work. I drive about 80 miles round trip and use around 30% of the battery daily, so when I get home it’s around 50%.

Lithium ion batterys degrade from time.
[TIME x SOC x TEMP] is the driving factors.

At elevated SOC the degradation is higher.
At elevated Temp the degradation is higher.

First thing, stop charging when you get home. Set the charging to complete shortly before you need to drive away.( its done on the screen in charging)

Second thing, if only using 30% SOC during a regular cycle; lower your cycle to charge to 50 to 60% and arrive with 20 to 30%.
If you need more reserve ad that to the charge level but dont ad more than needed.

If you have your car at 80% for the most part of the day, for 5 months at 25C / 77F you probably have had about 5% degradation from time x SOC x temp only, without even using the car.
If it is standing in higher temps, degradation will be higher.

I suggest reading this:

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

As many of you know, my 2018 LR-AWD has always shown approx. 310 miles since I got it in Dec 2018, mfr'd Oct 2018. Here's today's Stats chart: Up until about 15k miles, the chart shows seasonality, since the Stats developer was using the SOC api that didn't factor temps. I think it was January...

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