Estimated Battery Degradation - Model 3

[hgmichna]

To my knowledge the predicted mileage reflects the actually charged capacity of the battery. It uses a fixed factor.

You can use the displayed mileage when fully charged when the car is young, i.e. not yet degraded, as a reference point for the full capacity. For example, if your car showed 300 miles after you had charged it fully a few times after buying it, but now shows 270 miles, then you have 10% degradation.

This is not absolutely exact, but comes pretty close to actual degradation. It is a simple, easy, quick method.

On the Teslalogger Degradation page you can see statistics on mileage for your exact Tesla type over miles driven. This allows you to compare your individual car to others of the same type.

 

[AndrewGR]

Here’s another Teslafi report - my 20,000 mile LR AWD. Over time the report has shown the battery to be well below, and reasonably above, the ‘fleet average’. At the moment, after about 18 months it is below average having been close for some months. There is clearly no point in worrying about short term fluctuations - and probably little to be gained from trying to understand them!

 

[GeorgeSymonds]

Without reading back over numerous pages, for those seeing what they think is degradation, have they looked at the BMS calibration process? It seems the BMS drifts and leaving the car over night, not charging, at states of charge across the full range (ie a few at below 50% as well as above 50%) gives the BMS better data points to work on. Just about everybody that tries is sees over a week or so their reported battery range improve. I say "reported" as the actually battery is unchanged, its just how well it's measured.

 

[Adopado]

Just about everybody that tries is sees over a week or so their reported battery range improve. I say "reported" as the actually battery is unchanged, its just how well it's measured.

I think that though the battery is unchanged by these calibration "losses" it does mean that it would be harder to access the "hidden percentage". In theory your battery would have a higher capacity than displayed but you would have to drive down to 0% or 0 miles ... and then keep driving "blind" to use the unreported kWhs! I don't think many of us would be prepared to do that so I suppose it does impact our use in a real way after all.

 

[spon88]

View attachment 678368
Here’s another Teslafi report - my 20,000 mile LR AWD. Over time the report has shown the battery to be well below, and reasonably above, the ‘fleet average’. At the moment, after about 18 months it is below average having been close for some months. There is clearly no point in worrying about short term fluctuations - and probably little to be gained from trying to understand them!

I reckon this sums it up. I'm still unsure as to how the BMS predicted mileage is a reflection of the actual state of the pack i.e. is it really degraded or a calibration problem, but I'm not going to worry about it too much

 

[nxsynjs]

Battery degradation is a rabbit hole that can drive you bonkers if you go too far down.. I almost succumbed but then I thought "since when did I worry when my ICE car showed 15 miles less range on a full tank of fuel that it did 3 weeks ago" or "ohnoes my ICE cars only does 31mpg, when Mercedes says it'll do 37"