Battery Degradation - How concerned should I be?!

[EV-Rev]

So what happened when you actually charged to 100% and let the battery balance? What did you see in the car / tesla app when you did that (NOT Teslafi?).

I need to try again... if i recall when I first started to your Teslafi it was topping at 306 ish. Then suddenly it went to 311 ... could be cause of the 100% charge i had done around that time (i need to go back and check). I will try it again and see.

The youtube speech above i agree with other posters does not seem to add up. The car i believe will show 100% if you charge all the way even if the battery actual capacity went down.

I just thought the fluctuation of the range estimated seemed vary so much that it caused me to stop and worry. I love the car and really i cannot ever go back to any other make or model!

Thanks for all the feedback.

 

[jjrandorin]

I need to try again... if i recall when I first started to your Teslafi it was topping at 306 ish. Then suddenly it went to 311 ... could be cause of the 100% charge i had done around that time (i need to go back and check). I will try it again and see.

The youtube speech above i agree with other posters does not seem to add up. The car i believe will show 100% if you charge all the way even if the battery actual capacity went down.

I just thought the fluctuation of the range estimated seemed vary so much that it caused me to stop and worry. I love the car and really i cannot ever go back to any other make or model!

Thanks for all the feedback.

So if I am understanding correctly (please correct me if I am wrong), you started this post about battery degradation based on what teslafi is telling you.... not based on actually charging the car to 100% and seeing what figure the car gives you when charged to 100% and allowed to balance (complete a 100% charge).

Is that an accurate statement?

 

[ewoodrick]

This is outdated info. Not required any more. 90% is fine. Balancing occurs continuously. Recalibration works fine going a bit lower than usual and charging to 90%.

No, there have been numerous situations where charging to 90% doesn't completely reset things. 100% does. 80% definitely doesn't get it. Kim and Elon's discussion of 90% gets much closer, but not completely there.

Heck, just use the car and take a trip every few months!

 

[darth_vad3r]

No, there have been numerous situations where charging to 90% doesn't completely reset things. 100% does. 80% definitely doesn't get it. Kim and Elon's discussion of 90% gets much closer, but not completely there.

Heck, just use the car and take a trip every few months!

You said “to allow the battery cells to equalize”. That’s “balancing” and different from the BMS calibration incorrect range estimate “issue”.

Balancing occurs continuously now according to @wk057 discussions with Tesla folks and his looking at the firmware and cell voltages live.

 

[ewoodrick]

Yes there is balancing going on all the time. But, AFAIK, complete balancing doesn't occur until all batteries come up to max charge/voltage.

 

[darth_vad3r]

Yes there is balancing going on all the time. But, AFAIK, complete balancing doesn't occur until all batteries come up to max charge/voltage.

The ongoing balancing that is going on seems to result in such miniscule deltas between bricks that I can’t imagine how much more “complete” taking it to 100% could be?

 

[ewoodrick]

The ongoing balancing that is going on seems to result in such miniscule deltas between bricks that I can’t imagine how much more “complete” taking it to 100% could be?

That's easy, enough to get all the numbers right.

 

[darth_vad3r]

That's easy, enough to get all the numbers right.

LOL ... but I mean that extra-uber-super-duper-really-balancing at 100% that we are theoretically talking about that's "better" than the continuous-at-any-SoC-balancing isn't going to affect the battery range estimate, so ... I don't see a big benefit to it.

Stretching the battery and letting the car see how far it can go over large depth of discharge is what helps the calibration and the range estimate (rated range). I don't think balancing is a major factor here at all due to the fact that continous balancing keeps the bricks in very close balance.

 

[Wennfred]

Percentage makes no sense to me. If I see a road sign that says Albuquerque is 100 miles away and my car shows 150 miles of range remaining, then I have a pretty good sense that I'll make it. Combine that with the trip graph and all your worries will melt away.

+1

 

[Wennfred]

Great video on this topic, @ 50,000 miles

 

[ewoodrick]

LOL ... but I mean that extra-uber-super-duper-really-balancing at 100% that we are theoretically talking about that's "better" than the continuous-at-any-SoC-balancing isn't going to affect the battery range estimate, so ... I don't see a big benefit to it.

Stretching the battery and letting the car see how far it can go over large depth of discharge is what helps the calibration and the range estimate (rated range). I don't think balancing is a major factor here at all due to the fact that continous balancing keeps the bricks in very close balance.

But yet it seems as if it does. It may not be the batteries balancing, it may be as simple as the car now realizing what the correct voltage is when full. Remember, all cell voltages vary a little. All pack voltages vary. 100% is different on different packs. As well as the actual battery capacity is slightly different on each pack. The computers have to make informed SWAGs as to what 100% really is.

Don't forget that battery voltage is used to determine SoC. But it's the battery current and temperature that determines if it is charged.

 

[gilscales]

I was concerned about a recent 10-12 mile drop in the rated range display on my MR Model 3 until I watched this video...

It makes a great case for leaving the display on battery percentage versus range. Essentially, if you can still charge to 100% you have virtually no degradation. Leaving the display on percentage and using the energy graph set on 15 miles and average range to project your realistic range has been working great for me. I've found the range display to be almost useless now as it really depends on what type of driving you're currently doing and how aggressive you are. I just completed a 27.3 mile test loop in the city where the speed ranged between 30 and 50 mph. I consumed 9% which equates to a range of 303 miles even though my car has an EPA-rated 264 mile range and currently shows 252 miles range at 100%. Additionally, for 12 of those miles, I used the navigation function and "Trip" tab of the energy display and consistently used less energy than the car thought I would along that entire route and arrived with 2% more battery than the car was initially projecting. Try the percent display and use the energy graph. You might end up liking it more than displaying range.

Where to start with this video!
How about how many times this guy says degration, haha (see degradation)
I have never seen someone so misinformed in so many ways about Tesla batteries ever!

 

[Superspectral]

Tesla warrants their batteries for 8 years or 100,000 miles. I've driven mine 15,000 miles in 1 year. At most, I've lost 2%. I'll hit the mileage limit at 6.67 years. Extrapolating, linearly I'll lose 13.4%. So down to 270 miles. At worst, on long trips, I'd just have to supercharge a bit longer. Hopefully, I'll have traded it in for a better Tesla by then.

I think Tesla has conservatively set their warranty terms so that they are highly unlikely to replace many batteries due to slow normal wear and tear degradation. I suspect that most replacements will be due to sudden extreme failures early on in the lifetime of the vehicle.

So in a way, looking at battery degradation like divining teal leaves is an exercise in excessive worry over a moot point. If degradation is gradual, well then that is what you signed up for. I think if you stop obsessing, then practically speaking you won't notice degradation. Something that is worthy of a warranty repair will stick out like a sore thumb and bring attention to itself.

My point is - enjoy the car! Nothing is wrong!

 

[sperkin]

I got lots of thumbs downs or disagree when I talked about this before, but this is just 1 data point for you based on my own experience. You can ignore this if you like, but I think there is a small weight in the range estimate on your driving.

Since the price drop I drove my car like I stole it. I didn't care for the car or even washing it. I didn't even know I had lost some range until recently like 2-3 weeks ago. Since then, I washed my car, drove normally, and treated my car nice. Now I got my range back to 310 and you can see my estimated battery health is starting to climb.

I never charged to 100% though, I just leave it at 90-100% to avoid Supercharger fees. I usually just charge to 80%. This car used nothing but Supercharging since 2019.

 

[KenC]

Your 2nd image indicates that you have set your car to charge to 100% SOC.

I got lots of thumbs downs or disagree when I talked about this before, but this is just 1 data point for you based on my own experience. You can ignore this if you like, but I think there is a small weight in the range estimate on your driving.

Since the price drop I drove my car like I stole it. I didn't care for the car or even washing it. I didn't even know I had lost some range until recently like 2-3 weeks ago. Since then, I washed my car, drove normally, and treated my car nice. Now I got my range back to 310 and you can see my estimated battery health is starting to climb.

I never charged to 100% though, I just leave it at 90-100% to avoid Supercharger fees. I usually just charge to 80%. This car used nothing but Supercharging since 2019.

View attachment 440923 View attachment 440924 View attachment 440925

 

[SigNC]

Your 2nd image indicates that you have set your car to charge to 100% SOC.

He said as much in his post where he also said it was just set to that to avoid idle fees.

 

[sperkin]

He said as much in his post where he also said it was just set to that to avoid idle fees.

That is correct, sometimes Supercharger is too fast getting to 80%. I usually leave at around 82-88%. I set it to 100% to avoid idle fees in case I’m at the store or restaurant too long.

The picture was at 90% because I was doing an overnight charge at a hotel this weekend. I didn’t want to wake up at full charge and not driving the car much that day.

So I guess I’m not all that accurate when I said this car did nothing but Supercharge. This car actually charged twice overnight at a hotel this year. Once around March and once this weekend.

 

[hugh_jassol]

Where to start with this video!
How about how many times this guy says degration, haha (see degradation)
I have never seen someone so misinformed in so many ways about Tesla batteries ever!

Yeah. Holy cow. No one should watch this. Ever.

Well, I guess to be totally accurate, he probably doesn't have any "degration"

 

[rainforest]

So does charging to less than 90% really mess up the BMS calibration for anybody?

 

[Rocky_H]

So does charging to less than 90% really mess up the BMS calibration for anybody?

It's not so much about whether it's at 90% or less than 90%. It's about if you are using a very small band of the charging capacity. When you don't give the system a chance to see a broad range of energy in and out to see the high and low extents of the capacity, it starts losing the ability to calculate that accurately. All Teslas have been that way.