Could Acceleration Boost Cause Increased Battery Degradation?

[cypho]

I've notice a sharp increase in battery degradation that started immediately after purchasing the Acceleration Boost upgrade. Has anyone else who purchased the upgrade noticed this?

The black arrow in the attached graph shows the day that I purchased the upgrade.

My degradation rate increased 10x after the upgrade. Pre-upgrade I lost 5 miles of range over 10K miles. Post upgrade I've lost 10 miles of range over 2K miles. My total degradation so far is only 15 miles, so it is not too terrible overall, but the timing is suspicions.

Do you think it is a coincidence that I purchased the upgrade right before the drop began?

 

[NotADoctor]

I saw the same thing. I thought maybe it was just the colder temps...

 

[DirtyT3sla]

Theoretically yes, but it's probably just a coincidence. Here is my chart with no acceleration boost.

 

[DirtyT3sla]

I saw the same thing. I thought maybe it was just the colder temps...

Displayed range is not based on environmental factors: Range Tips

"Why is my displayed estimated range decreasing faster than miles driven?
Displayed range is based on regulating agency certification (EPA) and is not adapted based on driving pattern. Your driving behaviors and environmental conditions can impact your car's efficiency, and therefore its range. To see estimated range based on personalized energy consumption, open the Energy app."

 

[LCR1]

Acceleration doesn't come free, you need more power to accelerate faster. That power comes from draining the cells faster which will put more wear on them. Early P90D cars had this issue with the battery and Tesla made several revisions to that pack. I can't see the acceleration came from anything other than increasing power output, it was what, a 10% boost in time; you'd be hard pressed to show where you gained 10% without boosting power.

 

[AlanSubie4Life]

Displayed range is not based on environmental factors: Range Tips

The rated range display will change depending on battery temperature.

Do you think it is a coincidence that I purchased the upgrade right before the drop began?

Probably. You had just come out of the (theoretical, hypothesized by me, heretofore unproven) "hidden capacity loss region" where your rated range was above 310 rated miles but displayed as 310 rated miles. So you're just continuing the downward curve (concealed until you hit 310 rated miles) that has been present on your car from day 1.

Most likely the overall downward trend is being exacerbated by the lower temperatures right now, though I don't know where you live.

I recommend checking out your range with a piping hot battery (flog it on the freeway for a couple hours and drive to a Supercharger and precondition it) charge to higher than 80% and reevaluate to see where you are at.

 

[cypho]

Displayed range is not based on environmental factors: Range Tips

"Why is my displayed estimated range decreasing faster than miles driven?
Displayed range is based on regulating agency certification (EPA) and is not adapted based on driving pattern. Your driving behaviors and environmental conditions can impact your car's efficiency, and therefore its range. To see estimated range based on personalized energy consumption, open the Energy app."

You are assuming that the environment does not impact the battery capacity. But if you can't pack as many kwh into a cold battery(I have no idea if that is the case) then we would see the displayed range go down when it is cold.

 

[cypho]

Most likely the overall downward trend is being exacerbated by the lower temperatures right now, though I don't know where you live.

I recommend checking out your range with a piping hot battery (flog it on the freeway for a couple hours and drive to a Supercharger and precondition it) charge to higher than 80% and reevaluate to see where you are at.

Hopefully that is the case, it is cold here ( mostly in the 0F - 10F range recently ).

 

[AlanSubie4Life]

Hopefully that is the case, it is cold here ( mostly in the 0F - 10F range recently ).

Apparently there are some issues with how TeslaFi extrapolates, as well. So maybe just try doing the extrapolation yourself when the battery is very cold (and overall just try to ignore that data).

 

[cypho]

Apparently there are some issues with how TeslaFi extrapolates, as well. So maybe just try doing the extrapolation yourself when the battery is very cold (and overall just try to ignore that data).

It is not a teslafi bug, the range shown on the screen tells the same story (charging to the same % shows lower range than it used to).

 

[SigNC]

Displayed range is not based on environmental factors: Range Tips

"Why is my displayed estimated range decreasing faster than miles driven?
Displayed range is based on regulating agency certification (EPA) and is not adapted based on driving pattern. Your driving behaviors and environmental conditions can impact your car's efficiency, and therefore its range. To see estimated range based on personalized energy consumption, open the Energy app."

Glad this is accessible on tesla site. So many people get this wrong.

 

[DirtyT3sla]

The rated range display will change depending on battery temperature.

Only when the battery is cold, partially blue, and has the snowflake symbol.

If winter really caused the stated battery range to go down, you'd see everyone in the north have 100% rated range dropping by 30-50%... so obviously that is not happening. It's been below 20F since last week for me, my car is using almost 400wh/mi daily (70 miles per day) and my rated 100% has not moved.

And I posted a link directly to Tesla's site stating as much.

 

[DirtyT3sla]

You are assuming that the environment does not impact the battery capacity. But if you can't pack as many kwh into a cold battery(I have no idea if that is the case) then we would see the displayed range go down when it is cold.

If cold temperature locks away capacity, the car turns part of the battery blue and has a snow flake symbol. If you don't have that, then capacity is unaffected by the cold.

 

[AlanSubie4Life]

It is not a teslafi bug, the range shown on the screen tells the same story (charging to the same % shows lower range than it used to).

As long as both the % and range are coming from the car it is probably real then. I have no experience with this, but there are two variables and two SoCs associated with "Battery Level" and "Usable Battery Level".

The SoC associated with Usable Battery Level goes down as your battery cools, so it will project to closer to your real 100% value even when your battery is cool. Meanwhile, the apps use an SoC associated with the other value (Battery Level), for some reason, so that SoC does not change as your miles drop, so your projected full value drops. (The plot you provided above uses that unadjusted battery SoC%, from what I've been told...I have personal experience only with Stats.)

So in any case (from what I understand) you have to use the percentage and miles from the car (not from any app). And even in that case I would wait for the car battery to be super hot to do any projections.

 

[AlanSubie4Life]

Only when the battery is cold, partially blue, and has the snowflake symbol.

That is not true that it is "only" then. I have seen multiple miles (about 6-7) lost overnight (I parked with a nice warm battery at about 89% SoC) at 35 degrees which were not vampire miles (I could tell because the SoC % in my Stats app did not change), and there was no snowflake.

The battery energy is quite sensitive to temperature and small but noticeable changes will occur before you get the snowflake. Of course, if you have significant cooling, and the snowflake, you can definitely see even more loss. It is more of a continuum as far as I can tell.

In any case, it is very much not recommended to read much into the numbers when the battery is chilly. To remove any doubt, get it nice and hot. Then charge it rapidly (Supercharging required) to 80% plus. Then extrapolate. Then you don't need to worry about this factor and how much of a factor it might be. If it's cold enough this process may not be possible. You need to see a Supercharge at maximum rate; it can't be less than the taper.

 

[mbdionio]

Since early January, I started to just use the ChargePoint at twice a week and stopped using my Tesla charger at home. I noticed that my predicted 100% SOC started to increase (from 298-299 to around 302 by end of Jan). Now it improved to 306.

Not sure if charging less frequent and lesser current is contributing to this behavior.

 

[AlanSubie4Life]

my car is using almost 400wh/mi daily (70 miles per day) and my rated 100% has not moved.

I agree that if you're using the Tesla % and the Tesla-reported miles you'll probably not see much shift in the projected 100% value. See above.

It sounds like you have a lot more experience with this than I do, though - a lot of what I am stating above has been from people who have provided supporting data, but it is still not personal experience, so it could be wrong.

So you're saying that your rated miles displayed at 80% right now are the same as they are in the summer time? When you see the snowflake in the morning, doesn't the car display a lower SoC % than what you targeted for your overnight charge? I've only seen the snowflake one time and there was no blue bar associated with it (it was about 40 degrees but the car was thoroughly cold soaked to that temperature). So very little experience with how the SoC indicator behaves. But based on what I've been told, if your car is charged warm to 80%, and then is super cold-soaked over a day or so, you'll come out to a car at 75% (or whatever), with a snowflake? And rated miles will adjust as you would expect, if you're using distance rather than energy display? So if you take the available miles and divide by 75% you'll still end up at close to the correct 100% value? Is that right?

 

[DickBlonov]

Only when the battery is cold, partially blue, and has the snowflake symbol.

Incorrect. The rated range is dependant on battery temperature. The battery may be outside it's optimal temperature range without a snowflake or blue bar display. And battery warming might may turn on without that snowflake or blue area display.

Phil

 

[DirtyT3sla]

I agree that if you're using the Tesla % and the Tesla-reported miles you'll probably not see much shift in the projected 100% value. See above.

It sounds like you have a lot more experience with this than I do, though - a lot of what I am stating above has been from people who have provided supporting data, but it is still not personal experience, so it could be wrong.

So you're saying that your rated miles displayed at 80% right now are the same as they are in the summer time? When you see the snowflake in the morning, doesn't the car display a lower SoC % than what you targeted for your overnight charge? I've only seen the snowflake one time and there was no blue bar associated with it (it was about 40 degrees but the car was thoroughly cold soaked to that temperature). So very little experience with how the SoC indicator behaves. But based on what I've been told, if your car is charged warm to 80%, and then is super cold-soaked over a day or so, you'll come out to a car at 75% (or whatever), with a snowflake? And rated miles will adjust as you would expect, if you're using distance rather than energy display? So if you take the available miles and divide by 75% you'll still end up at close to the correct 100% value? Is that right?

Every morning my displayed miles is 232-234 @ 80%. I'll attach my Teslafi range chart. You'll see miles start going down, but actually come up as the weather gets colder in December through February (The very bottom of the chart is 10/31/2019 - it has been below 20F for over a week now in the mornings, single or negative digits over night).

I never have a snowflake or blue battery because I park in a garage and I charge my car from 80% -> 90% while I get ready before leaving in the morning. This gives me anywhere from 25% to 50% regen when I leave. I also preheat the car for 10-20m while it's plugged in.

But if it's very cold and I don't go out at lunch, I can come out to a blue battery from being parked outside at work all day.

But yes, if your battery is blue, the displayed miles will be lower because that's all that's available. If you have a lot of blue area, your displayed miles can actually increase as you drive/warm the battery as those miles become available.

 

[AlanSubie4Life]

I never have a snowflake or blue battery because I park in a garage and I charge my car from 80% -> 90% while I get ready before leaving in the morning.

Yeah. A little hard to tell from your TeslaFi data because I can’t see the seasons, but anyway, this is what I meant - you don’t have the snowflake in your garage, but because the battery is cooler than it is during summer, it does seem to have a small impact on range at 100%. Can’t say that definitively with the data you have posted, but it certainly looks like it could be the case. That was my point - you can lose a few miles without showing the snowflake.

Everything you said in above post makes sense.