Battery degradation - 14% in 2 yrs and 24k miles

[pdk42]

My Model 3 LR is now just 2 years old and has 24k miles on it. It's been supercharged 42 times since new and 659 times at an AC charger (the joys of TeslaFi !). I've taken it to 100% fewer than 10 times. Range is now being reported as 267 miles (from 310 initially). That's a 14% loss and it's a lot more than I was expecting based on all the posts out there. The loss doesn't seem to have tailed off either - it just keeps going:

I'm not getting mega concerned just yet, but if it keeps on at this rate it'll start becoming more of an issue. As it is, my wife's ID.3, with a smaller battery), is currently reporting slightly better range!

 

[MrBadger]

Its quite possibly just the BMS drifting and nothing to do with physical degradation - raise a service request with your concern and hopefully they will remotely diagnose and if they are happy that there is no real hardware issue, they might reset the CAC (calculated amp-hour capacity) which will allow the BMS calibration to find a new normal over time. The fact that your range has significantly gone up and down at different shows that the battery probably has not physically degraded irreversibly.

 

[pdk42]

Its quite possibly just the BMS drifting and nothing to do with physical degradation - raise a service request with your concern and hopefully they will remotely diagnose and if they are happy that there is no real hardware issue, they will reset the CAC (calculated amp-hour capacity) which will allow the BMS calibration to find a new normal over time.

That would be a good result!

 

[DrJFoster]

You can help the BMS calibration yourself

TMC ran a long post/discussion on it here

How I Recovered Half of my Battery's Lost Capacity

Like many others, I have been concerned with loss of 100% indicated battery range on one of my Model 3s. My P3D (build date 9/13/2018, delivery date 10/8/2018) had gotten down to 270.3 miles at 100% charge on January 20, 2020, at about 30,700 miles, which is a loss of 40.8 miles since the car...

teslamotorsclub.com

..which appears to have been boiled down to the salient points, a few extra builds and more importantly instructions on what to do here

Tesla battery management system (BMS) calibration

Tesla battery management system (BMS) calibration instructions

tesla-info.com

 

[Jason71]

That would be a good result!

if it is real it is higher than average. on a recent thread most LR' owners of a similar age seemed to be reporting 290-295. Personally mine at 17K seems to vary between those 2 but I tend to keep it in the range of 40-80% most of the time which is good for the battery but not the BMS accuracy.

How much of that mileage has been spent towing your glider? Is it possible that the extra weight might either have put additional strain on the battery so your degradation is above average or confused the car as to how far it can go on a charge?

 

[pdk42]

if it is real it is higher than average. on a recent thread most LR' owners of a similar age seemed to be reporting 290-295. Personally mine at 17K seems to vary between those 2 but I tend to keep it in the range of 40-80% most of the time which is good for the battery but not the BMS accuracy.

How much of that mileage has been spent towing your glider? Is it possible that the extra weight might either have put additional strain on the battery so your degradation is above average or confused the car as to how far it can go on a charge?

I've not done that much towing. I've been to Wales twice with it on the back, and Germany there and back once. Maybe 2000 miles towing total. Average consumption towing is only about 375 Wh/mi, so it's not really that much worse than just driving it fast and hard. On the other hand - my usual charge cycle is 50-80% - so maybe it's just a BMS issues.

 

[pdk42]

You can help the BMS calibration yourself

TMC ran a long post/discussion on it here

How I Recovered Half of my Battery's Lost Capacity

Like many others, I have been concerned with loss of 100% indicated battery range on one of my Model 3s. My P3D (build date 9/13/2018, delivery date 10/8/2018) had gotten down to 270.3 miles at 100% charge on January 20, 2020, at about 30,700 miles, which is a loss of 40.8 miles since the car...

teslamotorsclub.com

..which appears to have been boiled down to the salient points, a few extra builds and more importantly instructions on what to do here

Tesla battery management system (BMS) calibration

Tesla battery management system (BMS) calibration instructions

tesla-info.com

Helpful post - thanks!

 

[tsh2]

I would tend to watch just the peaks of the graph. I believe the BMS is biased towards being pessimistic, so drift will always be on the side of lower range. Mine was drifting down over the last year, with only short trips and partial charges. A couple of long trips over the summer seem to have recovered most of the recent loss (year 1 still shows some drop as expected).

 

[pdk42]

So, an update. I booked a service appointment and Warwick SC looked at it (who are excellent BTW). They said diagnostics and logs showed nothing out of the ordinary but recommended I did a 100% charge, then take it down to 10-15%, then leave it for 24 hrs before charging it back to 80% ish. It worked! I got almost 4% back according to TeslaFi and the car’s own internal range display.

 

[Irata]

So, an update. I booked a service appointment and Warwick SC looked at it (who are excellent BTW). They said diagnostics and logs showed nothing out of the ordinary but recommended I did a 100% charge, then take it down to 10-15%, then leave it for 24 hrs before charging it back to 80% ish. It worked! I got almost 4% back according to TeslaFi and the car’s own internal range display.

Over how long did you do the drop to 10-15%?

Was it a single trip or over a few days. If over days, I wonder if it gave the BMS multiple calibration points.

 

[pdk42]

Over how long did you do the drop to 10-15%?

Was it a single trip or over a few days. If over days, I wonder if it gave the BMS multiple calibration points.

It was over about a week. I did one drive that took it down to about 65%, then a return down to about 25% then a few days of local trips until it got to 13% when I left it for 24 hours.

 

[GeorgeSymonds]

It was over about a week. I did one drive that took it down to about 65%, then a return down to about 25% then a few days of local trips until it got to 13% when I left it for 24 hours.

That sounds very like the type of thing you need to do to help calibrate the bms.

Either way, good news it’s made a difference to you

 

[Lx2m3]

So, an update. I booked a service appointment and Warwick SC looked at it (who are excellent BTW). They said diagnostics and logs showed nothing out of the ordinary but recommended I did a 100% charge, then take it down to 10-15%, then leave it for 24 hrs before charging it back to 80% ish. It worked! I got almost 4% back according to TeslaFi and the car’s own internal range display.

Can you tell me where the Warwick sc is please? I didn’t know there was one and I can’t find it.

 

[pdk42]

Sorry - I meant

Can you tell me where the Warwick sc is please? I didn’t know there was one and I can’t find it.

Sorry - I meant Stratford !!

 

[Epyx]

I was having a very similar issue as OP.
26000km on odometer, two years old.
438km range at 100%. In the very beginning, two years ago, it was 502km.
Followed advice from VanillaAir_UK and asked Tesla SC to reset CAC 3 weeks ago.
Also, BMS calibration done: From 10%, charging to 100%. Did that twice.
Furthermore, Since then, I’m now practicing a new charging discipline as described above. No more small increments, e.g. from 60% to 80% but from +-20% to 90%.
Now I read 463km of range at 100%.
The proof of the pudding would be to make a long trip in one go from 100% to 5% and see actual kwh consumption in order to measure real battery degradation.
But so far I’m happy what I see.

 

[JIBYC]

On charging habit, I wonder if Octopus Go + TeslaFi stop commands are messing with the BMS estimates?

Can't see why it would given official guidance is "always plug in, and set limit to 90%".

 

[Irata]

It was over about a week. I did one drive that took it down to about 65%, then a return down to about 25% then a few days of local trips until it got to 13% when I left it for 24 hours.

Thanks. That's great, aligns nicely with the many other reports of the BMS calibration.

Sample points at different SOC seems to be the key here. For the M3 4-6 hours seems to be enough per SOC for the BMS to take a stable measurement.

 

[Envchem]

BMS needs to be re-calibrated from time to time to see actual battery state. A year ago when my front motor died SC did a BMS recalibration. You can see the obvious results on the graph:
At the moment I am on 40k miles. Driving 110miles every day during the week. My charging regime is to 90% every day except the weekend where unless we have a trip scheduled I charge to 50% and leave it. Winter now started taking its toll but overall quite happy with battery state

 

[Adopado]

Average consumption towing is only about 375 Wh/mi, so it's not really that much worse than just driving it fast and hard.

In fact that's nowhere near as demanding as fast and hard ... I can't therefore see that "stress on the battery" comes into it.

 

[Adopado]

BMS needs to be re-calibrated from time to time to see actual battery state. A year ago when my front motor died SC did a BMS recalibration. You can see the obvious results on the graph:
At the moment I am on 40k miles. Driving 110miles every day during the week. My charging regime is to 90% every day except the weekend where unless we have a trip scheduled I charge to 50% and leave it. Winter now started taking its toll but overall quite happy with battery state
View attachment 726605View attachment 726605

Presumably if the rest of the fleet had had a recalibration at the same point it would be closer to where you are now.