DirtyT3sla
Member
Here ya go. Over 800 data points that do not show a correlation to 100% charge related to temperature.
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Could Acceleration Boost Cause Increased Battery Degradation?
- Thread starter cypho
- Start date
Here ya go. Over 800 data points that do not show a correlation to 100% charge related to temperature.
AlanSubie4Life
Efficiency Obsessed Member
Well, that actually does show a very clear correlation. It becomes even more clear if you eliminate data from the first ~9 months of ownership (try it and post! - would be interesting) I would guess (there is some flatlining that takes place when the battery has tons of capacity - very evident in your plot from the upper group of data at cold temperatures - though it could be other factors at play there too). Regardless there is a clear correlation.
But it is small (as I said!). And I am talking about the TeslaFi projections - certain ways it projects range use a different SoC in the API and will produce erroneous points if you have the snowflake or if the battery is chilly as I said. I don’t use TeslaFi so I’ll let other users chime in with details if they want. Anyway. It doesn’t matter. Warm up your battery before making projections, for the OP here. And don’t use TeslaFi projections. Use the car, only after charging to over 80%.
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AlanSubie4Life
Efficiency Obsessed Member
Yes. This illustrates the error due to the API value which is used. My understanding based on that post is that if you use the car % and miles this phenomenon will be much much weaker.
DirtyT3sla
Member
R^2=1 means perfect correlation. This low R^2 means there isn't a correlation.
I'm not sure why you want to exclude any data.
AlanSubie4Life
Efficiency Obsessed Member
The coefficient of determination is not the same as the correlation coefficient, though they are related. In this case the correlation is 0.28, which is a weak but likely significant (given the number of data points) positive correlation. Just look at the data cloud and it's pretty obvious there is a relationship!
The low R^2 just means there are other contributors to the variation (which I would expect, as well). That's why I was curious to exclude the data from your first chilly weather experienced with the car early in its life, because I believe that initially the car has excess energy so the impact of cold is not as visible due to some tricks (this is a hypothesis, it is not proven). However, there could also be other factors that explain that upper group of data. (E.g. Could also be a change in charging habits - charging car immediately after driving rather than waiting until evening when the car has cooled off - this could result in different battery temperatures when TeslaFi logs the datapoint.)
Anyway, the OP just needs to warm up the battery, and use the car's data. Then you don't need to worry about this.
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I would just point out that Teslafi's X-axis is not consistent. The drop in the 10k range is compressed over a short period on the x-axis, indicating a precipitous drop, but if you stretched that over the same period on the x-axis as the 9k datapoints, it'd be far more gradual. This x-axis inconsistency is one reason why I find the Teslafi charts almost useless when trying to interpret trends.
Second which soc %age api is Teslafi using? There are two. One is "usable SOC" and one isn't. The "usable" one is the one Tesla uses. I've seen three 3rd-party apps (Stats, EV Watch and AutoMate) all use the other one, and that one is temperature-affected. That's why the Stats Battery Health chart when exported and with temp data overlaid will look like this:
It totally could be related to the weather, random chance, or some other factor. But the change is not just an artifact of the x-axis.
I lost 5 miles in the first 10K miles (pre upgrade). And then lost 10 more miles in the next 2k (post upgrade). 2x the degradation in 1/5th the time = a 10x increase in the degradation rate.
AlanSubie4Life
Efficiency Obsessed Member
Remember that loss of capacity is actually the highest at the very beginning. This is likely cleverly hidden from view by Tesla by packing more energy into each rated mile when the car is new. It's a good way to make sure that everyone starts out with the same number of rated miles even if they have small differences in initial full pack capacity. Again, this is just a theory on my part, but it's supported by various pieces of evidence (detailed elsewhere). Really need someone with a brand new AWD to check their discharge constant or hook up SMT and observe over time, just to get another piece of confirming evidence. Or VERY carefully document a charging event (rated miles added, time, voltage, and current), and then check again later once their battery shows loss of capacity. Would be awesome.
Anyway, my point is that likely you had loss of capacity in that first 5k miles (and quite considerable loss too), it just doesn't show up in the rated miles and it's very hard to see, except through very careful observation of charging events or the trip meter when the car is new. So your degradation rate has not actually increased - it may have even slowed down! From a physical standpoint, and from SMT readbacks, you almost certainly did have a lot more than 76kWh (310rmi) available when the car was new. It's common to see reports of 78kWh or more when the car is new. But these cars (2018/2019) do not show 318 rated miles - they show 310 rated miles.
My guess is you started with the equivalent of 317-320 rated miles, reduced to 305 rated miles before the upgrade (4.5%), and now have lost an additional 2-4% (295 to 300). And remember that some of that may be due to temperature - warm that battery thoroughly before drawing such a conclusion about where you stand today. So perhaps 15 miles lost in the first 10k, and at MOST 8-9 miles lost in the last 2k.
All TBD. More confirming data from brand new owners would be great, but unlikely.
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scubastevo80
Member
To answer your question (I think we got a bit off track here), I’d say the performance boost causes no additional degradation that you wouldn’t see on a “stock” performance model that puts out more power through the same battery.
Did you have an AWD with Accel boost?
So far 100% of the people posting in the thread that claim to have purchased the boost report seeing what looks like boost related battery degredation.
Even if I assume that I started with 320 miles, my post upgrade degradation rate is 5x the pre upgrade rate. I would have had to start with 360 miles for what I am seeing to be explained by hidden initial capacity.
AlanSubie4Life
Efficiency Obsessed Member
Sure. But as I said to know where you actually stand today you would have to have a warm battery.
Also, somewhat strangely, the drops in range do tend to come in chunks. Not sure why.
scubastevo80
Member
No I don’t have it and my range again dropped once winter hit. If my Stats app wasn’t messed up I’d post it, so I’m still of the belief the boost upgrade isn’t causing true degradation.
so i purchased AB for two days, and before my 2022 MY LR 90% used to indicate 464km
after 2 days of AB, it dropped to 461 km......
i just refunded the AB
after 2 days of AB, it dropped to 461 km......
i just refunded the AB
You dropped it because you had a 0.65% drop in 2 days?!? You do realize that rounding errors could result in a 4.5km swing, right?
Lol. AB does nothing to battery degradation. Just coincidence. These batteries are robust. People seem to treat it like glass
Had the car for six months
Never a drop of Km
Since the tune instant drop
Too much of a coincidence that worries me , plus the op saw 10 percent degradation since the tune
That certainly worries me
There is almost no chance that the boost caused the little drop you had which, as was pointed out, is within the margin of error. You are going to have degradation and there is very little you can do about it, and it has zero to do with acceleration boost.
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