Battery degradation - 2019.32.2.2

[Allistah]

Here’s a recap from one of my posts in another thread. AWD with 9K, was charging a couple times a week to SOC 80% (rarely varied unless for road trip). Noticed a decline over summer from 310 down to 298. Switched to charging to 60% and after a couple times was back to 308 and as of last night it displays 310 rated range (using Stats).

Hey, that's great! Can you tell us more about your charges that caused this to happen? Are you using scheduled departure? Can you list out all the steps/charges that you did that lead up to this happening? I think there are a number of people here that would LOVE to try and duplicate your success!

On a side note, looking at a charge I did from about five days ago, it looks like the higher you get up in charge %, the bigger the gap is. Look at the "Range Difference" column which just takes the battery range and figures out what it should be if we got a perfect 310 miles at various "Battery Levels". For example, for 10% below, 310*(10/100)=31 (10% of 310 max miles is 31 miles) to get the "Perfect Range" column, then I just took the difference between the perfect range and the "Battery Range" which was reported by the car. The "Range Difference" grows further negative, the higher the charge got. I stripped out all the lines except the ones where it ticked over to a round number for this post so we could see a trend.

I guess this doesn't work in a single charge like I'm looking at. For some reason, I'm feeling like a scheduled departure is what is triggering this to happen for some reason.

 

[Allistah]

Here is something else that I noticed about "Scheduled Departure" charging. It seems like it does it in two parts. It charges the bulk of it up and then stops. Then shortly before your scheduled departure time, it finishes things off and brings up the charge to the specified amount and gets the car ready to go. I'm wondering if there or something in there that's helping bring the ranges back in line.

Here is what I'm talking about with scheduled departure. This was a charge set to 90% and a scheduled departure time of 6am. It broke it up into two chunks for some reason. It started at 19%, then stopped at 89% at 5:04am, then started again at 5:35am and charged for 10 more minutes to get that last percentage in there and ended at 5:42am - ready for departure at 6am. Pretty interesting..

 

[Sherlo]

@Sherlo - Can you give us some details around exactly what you were doing before with your charging routine and what you did to get this to work for yourself? Did you use scheduled departure and what number was it that worked for you? How low do you typically go before charging?

Up until a few weeks ago, I was charging to 80% with 30A home charger a couple times each week (don’t have much of a commute). Wasn’t plugging in daily, only to charge. After seeing decline from 308 to 298, the only change I made was to the charge level 60% (no daily plugging in just as necessary a couple times a week when it got down to 25-30%). Not using schedule departure either. Within a couple cycles, it returned to 308 rated range (increases of 4-5 miles each time).

I’m curious to see how it works out for others making an adjustment. I’d like to chalk it up to more than just a coincidence.

 

[Allistah]

Up until a few weeks ago, I was charging to 80% with 30A home charger a couple times each week (don’t have much of a commute). Wasn’t plugging in daily, only to charge. After seeing decline from 308 to 298, the only change I made was to the charge level 60% (no daily plugging in just as necessary a couple times a week when it got down to 25-30%). Not using schedule departure either. Within a couple cycles, it returned to 308 rated range (increases of 4-5 miles each time).

I’m curious to see how it works out for others making an adjustment. I’d like to chalk it up to more than just a coincidence.

Thanks for sharing - yeah, I'd like to do something like that as well so I think it sounds like a number of us are going to give this a shot and see what happens. Really cool to hear that you're not using the scheduled departure feature. The more we know, the more we can narrow it down. I think tonight I'm going to set mine at 70% and see what happens, unless I get some more data from people that change my direction.

@Sherlo - Since you lowered your charges to 70%, did you change the point where you would charge back up to 70% or did that stay constant around 25-30% like you mentioned above?

 

[Sherlo]

Thanks for sharing - yeah, I'd like to do something like that as well so I think it sounds like a number of us are going to give this a shot and see what happens. Really cool to hear that you're not using the scheduled departure feature. The more we know, the more we can narrow it down. I think tonight I'm going to set mine at 70% and see what happens, unless I get some more data from people that change my direction.

@Sherlo - Since you lowered your charges to 70%, did you change the point where you would charge back up to 70% or did that stay constant around 25-30% like you mentioned above?

Yeah, I considered charging daily but decided against it given I work from home some days and don’t use enough on those days to warrant a charge back up. That was going to be my next change if the reduction to 60% didn’t help.

Additional note, this past weekend charged up to 90% (not using scheduled departure) and it continues to maintain the 308-09 rated range. So far so good.

Hope this works for you too.

 

[Allistah]

Yeah, I considered charging daily but decided against it given I work from home some days and don’t use enough on those days to warrant a charge back up. That was going to be my next change if the reduction to 60% didn’t help.

Additional note, this past weekend charged up to 90% (not using scheduled departure) and it continues to maintain the 308-09 rated range. So far so good.

Hope this works for you too.

Thanks! I hope it works for me too. I see you're in the Bay Area. We're out in Modesto and I go all the way to Menlo Park every day. (Wife drives the car, but only to Pleasanton) so we eat up around 120-150 miles every weekday. Hoping that this will help reset things for us. Right now Stats is saying 100% is at 288 miles. Will see and report back!

 

[Sherlo]

Thanks! I hope it works for me too. I see you're in the Bay Area. We're out in Modesto and I go all the way to Menlo Park every day. (Wife drives the car, but only to Pleasanton) so we eat up around 120-150 miles every weekday. Hoping that this will help reset things for us. Right now Stats is saying 100% is at 288 miles. Will see and report back!

Tough commute...but at least you are riding in style

 

[Allistah]

Yeah its rough - I can't do it anymore which is why my wife drives to Pleasanton and then I take a work Shuttle from there the rest of the way. I do notice that her tolerance for other people on the road is slowly melting away and she gets more and more agitated over time. That leads to more aggressive driving on her part. It's funny because when we first got it, she only wanted to drive in "Chill" mode, and then one day she got so comfortable with the car that Chill didn't have enough power for her anymore. Now she's comfortable in standard mode.. She would scare the hell out of me if we had a Performance. lol

 

[Boomer543]

Man, I hope this works. Will start trying this tomorrow. Like others, I've experienced a precipitous decline in rated range. My usual practice is to charge to 80% most days except on the weekends. Have really been bumming out about the loss of range. Was hoping it was weather related (been getting cold in the Northeast) but after reading Tesla's FAQs, can't blame the weather.

 

[rad1027]

Thanks for sharing - yeah, I'd like to do something like that as well so I think it sounds like a number of us are going to give this a shot and see what happens. Really cool to hear that you're not using the scheduled departure feature. The more we know, the more we can narrow it down. I think tonight I'm going to set mine at 70% and see what happens, unless I get some more data from people that change my direction.

@Sherlo - Since you lowered your charges to 70%, did you change the point where you would charge back up to 70% or did that stay constant around 25-30% like you mentioned above?

Absolutely agree on reporting back. I believe this way we can all troubleshoot together and find a consensus (using data points) in order to potentially determine solutions.

On that note, last night I decided to conduct another "experiment." I charged again to the 70% mark, but lowered the amps to 25A from 48A max. Scheduled my normal departure time. Woke the car up ready to leave and had 210 miles displayed. So now I have a loss of 7 miles (per my calculations (310*.7 = 217 miles)). So I may try to charge overnight at 48A, 80%, and same scheduled departure time and see what happens. Ill report back.

 

[rad1027]

@rad1027 thank you. I will most definitely be trying this to see if this helps. Perhaps it breaks the routine of the car always being charged back to 90% which I have been doing as well. I also tried lowering the amps for charging and that didn’t do anything as still showing 4-5miles off so will try this and report back.

Thank you

No problem. I believe if we all report back what we did (all data points possible) and the outcome it will be better for all of us that are experiencing this "issue."

 

[Allistah]

Charging finished this morning at 70% @ 203 miles. (20A charge rate, dropped from 40A). 14 miles under the perfect range of 217.

 

[djgarrett21]

My rated range has taken a hit the last few months...

 

[jjrandorin]

Man, I hope this works. Will start trying this tomorrow. Like others, I've experienced a precipitous decline in rated range. My usual practice is to charge to 80% most days except on the weekends. Have really been bumming out about the loss of range. Was hoping it was weather related (been getting cold in the Northeast) but after reading Tesla's FAQs, can't blame the weather.View attachment 479294

I guess I dont get all the "angst" over what amounts to about 10 miles.. that people absolutely are NOT using on a daily basis. Its not like anyone with this issue is driving the total miles the car will go in any given day. They are looking at a number on the screen, and stressing out because its 10 miles lower than "it used to be".

its about the equivalent of getting 1/2 "Mile per gallon" less in a person's gas car, but I would virtually guarantee that none of you tracked your gas car down to the last 1/2 mile per gallon.

My car religiously charged to 279 at 90% (I even posted about how I must have a unicorn car) as I had 15k and it was charging to 279 at 90%. About 2 weeks after I posted that, it dropped from 279 to 270, then back up to 272 where it sits now on a 90% charge. I drive 80-100 miles a day, so am no where near "272" driven miles.

I guess I just dont get the stress, because we all didnt track our gas cars to the 1/2 MPG. The car IS going to lose some top in range over time, its how batteries work. Why is everyone concerned if their number is 5-10 miles off from what "it used to be", especially when it appears to be related to an update?

(honest question on why the stress, not trying to start a flame war, or generate angry posts)

 

[djgarrett21]

I guess I dont get all the "angst" over what amounts to about 10 miles.. that people absolutely are NOT using on a daily basis. Its not like anyone with this issue is driving the total miles the car will go in any given day. They are looking at a number on the screen, and stressing out because its 10 miles lower than "it used to be".

its about the equivalent of getting 1/2 "Mile per gallon" less in a person's gas car, but I would virtually guarantee that none of you tracked your gas car down to the last 1/2 mile per gallon.

My car religiously charged to 279 at 90% (I even posted about how I must have a unicorn car) as I had 15k and it was charging to 279 at 90%. About 2 weeks after I posted that, it dropped from 279 to 270, then back up to 272 where it sits now on a 90% charge. I drive 80-100 miles a day, so am no where near "272" driven miles.

I guess I just dont get the stress, because we all didnt track our gas cars to the 1/2 MPG. The car IS going to lose some top in range over time, its how batteries work. Why is everyone concerned if their number is 5-10 miles off from what "it used to be", especially when it appears to be related to an update?

(honest question on why the stress, not trying to start a flame war, or generate angry posts)

I believe it is less about the current value that the range has decreased and more about the long term trend that it may imply.

 

[dmurphy]

I guess I dont get all the "angst" over what amounts to about 10 miles.. that people absolutely are NOT using on a daily basis. Its not like anyone with this issue is driving the total miles the car will go in any given day. They are looking at a number on the screen, and stressing out because its 10 miles lower than "it used to be".

its about the equivalent of getting 1/2 "Mile per gallon" less in a person's gas car, but I would virtually guarantee that none of you tracked your gas car down to the last 1/2 mile per gallon.

My car religiously charged to 279 at 90% (I even posted about how I must have a unicorn car) as I had 15k and it was charging to 279 at 90%. About 2 weeks after I posted that, it dropped from 279 to 270, then back up to 272 where it sits now on a 90% charge. I drive 80-100 miles a day, so am no where near "272" driven miles.

I guess I just dont get the stress, because we all didnt track our gas cars to the 1/2 MPG. The car IS going to lose some top in range over time, its how batteries work. Why is everyone concerned if their number is 5-10 miles off from what "it used to be", especially when it appears to be related to an update?

(honest question on why the stress, not trying to start a flame war, or generate angry posts)

100% agreed!

Thing is, the "degradation" most folks are seeing is just in what's displayed on-screen. It's not directly, really related to how far the car will go.

When actually driving, the change in "how far can I go?" due to things like wind, elevation, HVAC, windows open, drafting behind semis, etc will ALL have a greater impact than the # that gets displayed after charging. I consider it "in the slop" so to speak. No real, discernible way to tell unless you own a wind tunnel & dynamometer.

Just get in the car and drive. If you know you'll be over 250 miles between charges, maybe use the map to find a Supercharger, or something like PlugShare.

Otherwise, I got 99 problems and range ain't one.

 

[Allistah]

This is a tiny blip, but charging to 70% last night gave a little blip up on the battery report. Will keep reporting back. We have a larger trip tomorrow so I'm not sure if I'm going to charge to 95% or 100%. Kind of undecided at this point. I'm thinking I may be under 10% tonight so I may go all the way to 100% tonight to see what happens. Here is the current chart after the 70% last night. Could be the start of something, could just be nothing since there are natural ups/downs all over the chart. Will see what happens over time.

 

[dhrivnak]

I too saw a loss of about 4 miles on my typical 90% charge. I assume they are tweaking the factors. When new I was getting 277 miles. Then with a software upgrade we jumped to 287. Now it charges to 284. So yes the number will change with software updates.

 

[Boomer543]

I guess I dont get all the "angst" over what amounts to about 10 miles.. that people absolutely are NOT using on a daily basis. Its not like anyone with this issue is driving the total miles the car will go in any given day. They are looking at a number on the screen, and stressing out because its 10 miles lower than "it used to be".

its about the equivalent of getting 1/2 "Mile per gallon" less in a person's gas car, but I would virtually guarantee that none of you tracked your gas car down to the last 1/2 mile per gallon.

My car religiously charged to 279 at 90% (I even posted about how I must have a unicorn car) as I had 15k and it was charging to 279 at 90%. About 2 weeks after I posted that, it dropped from 279 to 270, then back up to 272 where it sits now on a 90% charge. I drive 80-100 miles a day, so am no where near "272" driven miles.

I guess I just dont get the stress, because we all didnt track our gas cars to the 1/2 MPG. The car IS going to lose some top in range over time, its how batteries work. Why is everyone concerned if their number is 5-10 miles off from what "it used to be", especially when it appears to be related to an update?

(honest question on why the stress, not trying to start a flame war, or generate angry posts)

I know that it doesn't affect me on a daily basis, but it is concerning for a couple of reasons: (i) I want to know what is causing it so I know if there is a problem with the car or not, (ii) there will be times when I expect to drive much longer distances where the actual range will matter to me, and (iii) I want to make sure I know how my car works under different conditions so I don't get caught somewhere where I unexpectedly run into a range issue and face the prospect of a "flatbed of shame" moment.

 

[KenC]

Hey, that's great! Can you tell us more about your charges that caused this to happen? Are you using scheduled departure? Can you list out all the steps/charges that you did that lead up to this happening? I think there are a number of people here that would LOVE to try and duplicate your success!

On a side note, looking at a charge I did from about five days ago, it looks like the higher you get up in charge %, the bigger the gap is. Look at the "Range Difference" column which just takes the battery range and figures out what it should be if we got a perfect 310 miles at various "Battery Levels". For example, for 10% below, 310*(10/100)=31 (10% of 310 max miles is 31 miles) to get the "Perfect Range" column, then I just took the difference between the perfect range and the "Battery Range" which was reported by the car. The "Range Difference" grows further negative, the higher the charge got. I stripped out all the lines except the ones where it ticked over to a round number for this post so we could see a trend.

I guess this doesn't work in a single charge like I'm looking at. For some reason, I'm feeling like a scheduled departure is what is triggering this to happen for some reason.

View attachment 479268

Your percentage diff is the same.