Battery Degradation

[Lx2m3]

Not too happy about my battery degradation after only 3582 miles. The report says:
There are 56 vehicles with charges at your current odometer reading.
55 Vehicles have a higher range. 1 Vehicles have a lower range.
Your range is better than 2 % of similar users.
Data And Settings
Your Current Range Fleet Average Range Range Difference Percent
221.78 230.27 -8.49 96.3 %


High Range vs. Low Range
High Range Low Range Range Loss Percent Loss
235.65 221.78 13.87 6.25 %

Only used Supercharger 4 times and my normal charging limit is 80%. (M3 SR+)
How are others doing?

 

[NorfolkMustard]

It’s all estimated, and the difference is ≈8 miles. Draw the same graph on zero-base axes and the lines would be on top of each other

Don’t worry about it. Your charging regime sounds perfect

 

[davidmc]

Not too happy about my battery degradation after only 3582 miles. The report says:
There are 56 vehicles with charges at your current odometer reading.
55 Vehicles have a higher range. 1 Vehicles have a lower range.
Your range is better than 2 % of similar users.
Data And Settings
Your Current Range Fleet Average Range Range Difference Percent
221.78 230.27 -8.49 96.3 %


High Range vs. Low Range
High Range Low Range Range Loss Percent Loss
235.65 221.78 13.87 6.25 %

View attachment 559275

Only used Supercharger 4 times and my normal charging limit is 80%. (M3 SR+)
How are others doing?

Dont worry to much you get more than me (although if i run out before you its only a hop, skip and a jump to where you run out)

)

 

[davidmc]

The graphs that TeslaFi show are zoomed in (on the range axis) and really exaggerate the graph and data shown

It should look like this (my data that is shown above):

 

[Durzel]

The battery warranty is 8 years.

Range will go up and down depending on weather conditions, temperature, etc.

I used to have a big OCD about this stuff with other devices - my iPhone is currently on 93% battery health, and I used to worry about whether I was wireless charging it too much, not enough, not often enough, etc.

My Model 3 shows the battery percentage charged, rather than the range. I don't even really know how far that is in real terms, or what it is between when I might charged it a couple of weeks ago to the same percentage. I find that a lot easier to cope with.

 

[Jason71]

Dont worry to much you get more than me (although if i run out before you its only a hop, skip and a jump to where you run out)View attachment 559489 )

You notice that at 3000 miles you were also "well" below fleet average and were at a similar level to Lx2M3 and then your range actually went up after that and you were above for a while. Maybe his will as well. Though how much of this is due to constant tweeking of the algorithms who knows?

 

[davidmc]

You notice that at 3000 miles you were also "well" below fleet average and were at a similar level to Lx2M3 and then your range actually went up after that and you were above for a while. Maybe his will as well. Though how much of this is due to constant tweeking of the algorithms who knows?

There were report that firmware 2019.32.2.1 caused the battery range to drop (unknown cause tho?) and the range dropped at Odometer reading 2,163 miles and a range of 238 to Odometer reading 3,102 miles and a range of 228. This drop happened quickly in the space between 16/09/19 to 02/10/19 around 17 days. no one knows why. Could be BMS firmware calibration but that’s a guess?

It levelled out and then slightly increased after that firmware.

2020.4.1 did the same but only a small drop in comparison

Then after that until now I’m on 2020.16.2.1 its been nose diving again but seems steady with where it is now (not updated to latest yet, car wont download for some unknow reason when on Wi-Fi)

 

[VanillaAir_UK]

I wish TeslaFi wouldn't call it a battery degradation report. Its really a BMS range estimation report, which will vary for a number of reasons.

A significant one that affects how well the BMS can estimate the range can vary up and down over time. It is based upon lots of cumulative guesses over a period of time rather than a single point in time measurement = so the guesses can drift.

This apparently can be recalibrated to reduce the drift by occasionally letting SOC < 20% and close to 100% - the latter will also balance the cells, ie topping them all up to the same level. A bit like carrying a tray of drinks, whilst they may all start at a similar level, by the time you get to the table, they will all be at different levels. Balancing will top them all up to a more even level.

 

[Jason71]

Then after that until now I’m on 2020.16.2.1 its been nose diving again but seems steady with where it is now (not updated to latest yet, car wont download for some unknow reason when on Wi-Fi)

I'd stick on that version for now if I were you if you like having the ability to charge your car reliably at 32amps

 

[davidmc]

I'd stick on that version for now if I were you if you like having the ability to charge your car reliably at 32amps

I am i also think the car is telling me not to upgrade and refusing to download!

 

[Lupe]

I am also quite concerned about mine:

 

[VanillaAir_UK]

What charge settings are you using to plot on ? At the very least you want to uncheck 'Include Incomplete Charges' and for more accurate guesses, only include higher SOC sessions ('Include Charges Greater Or Equal To'). If comparing with the fleet, keep comparison to similar SOC (for reasons above), charge temperature (make quite a big difference) and for lower mileage cars, comparing against similar mileage vehicles.

But it does look a little low imho.

 

[Adopado]

Is it possible that 2 cars with same level of degradation could show differently on that graph? Does it take a account of some cars being driven very gently mostly around towns and others fairly hard down motorways ... or does it adjust for that? In other words is the predicted range on an individual car allowing for how it is most usually driven? (I used to monitor our ICE car mileage and I could easily get 10% better mileage than my wife even when driving, on average, at the same overall speeds (I tend to carry a bit more speed round corners so there's less braking and accelerating required to maintain the average).

 

[UrbanSplash]

I’ve done under 5k miles in 8 months and my 100% range has dropped from 309 to 288. It’s been dropping steadily. 20 miles range lost in 8 months? Surely not.

Maybe it’s the car hardly being used, and when it is it’s for pretty short journeys. I might try charging to 100%, which I’ve never done. Usual charge max is 80%.

 

[spon88]

View attachment 566672 I’ve done under 5k miles in 8 months and my 100% range has dropped from 309 to 288. It’s been dropping steadily. 20 miles range lost in 8 months? Surely not.

Maybe it’s the car hardly being used, and when it is it’s for pretty short journeys. I might try charging to 100%, which I’ve never done. Usual charge max is 80%.

My car is the same mileage but a couple of months older than yours. I'm currently showing 298 at full charge (M3P) but this has been as low as 293 and as high as 300 over the last few months. It varies with temp etc. I suspect you are looking at a BMS calibration issue (battery management). Worth trying a full charge and then running low - this may sort it for you. I also charge to 80% most of the time but do the odd one up over 90% to try to address this issue

 

[VanillaAir_UK]

They say occasionally letting it go below 20% along with the high SOC charge also helps with BMS recalibration.

 

[Lupe]

What charge settings are you using to plot on ? At the very least you want to uncheck 'Include Incomplete Charges' and for more accurate guesses, only include higher SOC sessions ('Include Charges Greater Or Equal To'). If comparing with the fleet, keep comparison to similar SOC (for reasons above), charge temperature (make quite a big difference) and for lower mileage cars, comparing against similar mileage vehicles.

But it does look a little low imho.

thatnks. Checked parameters and all in line with your suggestion. Not sure if something I should raise with Tesla. I guess I'm thankful it's a lease car as I'd be in meltdown by now if I'd forked out £55k for it

 

[Lupe]

I also always charge to 90%

 

[LongRanger]

Another part to this equation - does charging speed have any proven effect on these states being reported by users who could be worried about longer-term implications ?

So for example is there any benefit in mixing up supercharging, 50kw, 10A wall plug and 7.4kw 32A for example ?

Or will this type of battery always perform better longer term if trickle-charged vs 150kw+ rammed in there ?

Surely charge limit combined with charge rate is a more complete story around longer-term averages ?

Take my work iPhone for example, it’s less than a year old, I don’t give a second thought for how often I charge it, or from/to what percentage, or what amps I am using. It just gets used, charged, used etc - and after a year it’s at 90% efficiency, could I have made a huge difference to this if I had the faintest amount of respect for its battery ?

 

[Adopado]

View attachment 566672 I’ve done under 5k miles in 8 months and my 100% range has dropped from 309 to 288. It’s been dropping steadily. 20 miles range lost in 8 months? Surely not.

Maybe it’s the car hardly being used, and when it is it’s for pretty short journeys. I might try charging to 100%, which I’ve never done. Usual charge max is 80%.

As we keep saying on this forum, that mileage is an estimate. You might even cover more total miles despite starting out at the 288 estimate than when you were getting a 309 estimate. Your short journeys are probably not helping the BMS to track where things are at because a relatively high percentage of charge will be being lost when the car is not driving. I would say that's almost certainly a BMS calibration issue.

Changing to percentage display rather than mileage is recommended. If it were me, and if I was worried enough, I would be doing some long runs, planning to get home with 10% and then charging to a mid/high 85% and doing the same but then take it to 100% on the subsequent charge and run down to 20% on longish mixed runs... but really this recalibration will happen over time anyway unless your car remains virtually unused!