LiteEv
Member
I turned off Sentry mode and have some notifications such electrical system power reduced and parking brake functions degraded.
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How I Recovered Half of my Battery's Lost Capacity
- Thread starter SomeJoe7777
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- battery degradation Range
I had read post about a month before I got my car (Sep 2020) and made sure that I had a system in place so that my car “slept” for at least 6 hours, a couple times a week and at a different charge level.
So, does not only have to sleep for several hours, but also have to complete a charge before it takes an OCV reading? Or will it take an OCV reading either way, as long as the car has ample amount of “sleep”.
Also, how did the author of the original post verify that a successful OCV recalibration occurred?
So, does not only have to sleep for several hours, but also have to complete a charge before it takes an OCV reading? Or will it take an OCV reading either way, as long as the car has ample amount of “sleep”.
Also, how did the author of the original post verify that a successful OCV recalibration occurred?
I think you need to do a full charge. So my range was all the way down to 280 on a full charge from 310 when getting the car in sep '19. Over the past week I have been letting it go to sleep while unplugged, then just plugging it up in the morning to go to 90% (usually what I charge to) and there were no changes. yesterday I tried to charge it to 100%, but ran out of time. It was charging, but sitting on 100% for well over an hour. Today I am doing another 100% charge, but letting it complete. Right now teslafi says my estimated range went from 281mi yesterday, to 306mi today. ... But I won't know for sure until it completes the charge.
Am guessing if this is the range that actually comes up in the car #1, holy sh!t, can't believe that worked. and #2, it appears you may need to charge it to 100% after letting it go to sleep for a few days.
false alarm. Teslafi said my range went up, but my car still said 280 miles, so absolutely no change
DrGene
Member
I was wondering if the car charges to 99% of battery capacity does that mean the battery contains 99% of the original 100% energy in a new battery? If so my battery degradation would be just a loss of 3 miles from 310 miles. Now that I am charging a bit at a time with covid and im not going anywhere the mileage range has dropped to 282 miles and I only have 14000 miles on the two year old car. It has to be the loss of range as described in this article. Thanks very much for the article. This explains why people who drive their Teslas a lot seem to get better range and longer life and those who charge daily a little bit at a time lose range. Im certainly losing range due to driving very little and charging in smaller increments. I'll try to exercise the full range of the car more often and let it rest at low and high levels.
irelandm
Member
@DrGene Just a quick note: Based on your description, you aren't *actually* losing range or capacity on your battery, it's simply your computer registering a value based on "drifting" calibration. I would expect your "true" battery degredation is extremely minimal. The original post describes a sequence of charging/discharging events to help your computer's software re-calibrate its true capacity - while it's very interesting and potentially helpful, it's most likely not critically important.
Nichigo
Member
So I've had my car (M3 SR+) for 2 months and 3,000 miles. Started at 222mi @ 90% charge and that has since gone down to 210mi @ 90% charge. Until i read this thread, I had sentry mode on all the time, even at home. I disabled sentry mode at home and work starting yesterday and will report back later on on changes after the BMS has gotten a chance to catch up.
On a side note: sentry mode on at home had also given me an issue with scheduled charging. My car would start charging a few minutes after plugging in (I have the Tesla Wall connector) even if I had a later time scheduled. Tesla service center could not replicate the issue, and I had only gotten the idea of disabling sentry mode because of this thread. Scheduled charging is now working. Not sure why this is an issue. Both of these issues seem like things that should be fixed in software...
On a side note: sentry mode on at home had also given me an issue with scheduled charging. My car would start charging a few minutes after plugging in (I have the Tesla Wall connector) even if I had a later time scheduled. Tesla service center could not replicate the issue, and I had only gotten the idea of disabling sentry mode because of this thread. Scheduled charging is now working. Not sure why this is an issue. Both of these issues seem like things that should be fixed in software...
Envchem
Member
Hi all,
I think this is the best place to post this. So charging wise since the day I bought the car (almost a year ago) I charge to 90%. COVID restrictions haven't really affected my commute and since May i am doing 115 miles per day, except weekends). Before that was about 50 per day. Up to yesterday I was noticing on teslafi a degradation of about 3.5% from my initial range. So I was down to 298 from 309 which for a one year old car with almost 19k miles on the clock and winter time I thought it was to be expected.
Now yesterday I picked up my car from the SC after some warranty work that was done on it. As part of it due to a single error message that I got about a month ago the following parts were replaced as a precaution: pyro fuse, the high voltage controller and the high voltage controller harness. Left the car to charge overnight as per norm (90%) and this is the teslafi report from this morning:
Interesting right? Apparently my car now has more range since I bought it! I wonder if the BMS was reset. I will definitely keep a close eye and monitor this.
I think this is the best place to post this. So charging wise since the day I bought the car (almost a year ago) I charge to 90%. COVID restrictions haven't really affected my commute and since May i am doing 115 miles per day, except weekends). Before that was about 50 per day. Up to yesterday I was noticing on teslafi a degradation of about 3.5% from my initial range. So I was down to 298 from 309 which for a one year old car with almost 19k miles on the clock and winter time I thought it was to be expected.
Now yesterday I picked up my car from the SC after some warranty work that was done on it. As part of it due to a single error message that I got about a month ago the following parts were replaced as a precaution: pyro fuse, the high voltage controller and the high voltage controller harness. Left the car to charge overnight as per norm (90%) and this is the teslafi report from this morning:
Interesting right? Apparently my car now has more range since I bought it! I wonder if the BMS was reset. I will definitely keep a close eye and monitor this.
don’t pay attention to teslafi, look at the car itself. Teslafi reported I recovered almost the entire 30 miles I lost in a year, then the car said there was no increase in range at all.
Envchem
Member
Hi Sam,
Thanks for the feedback. I will do this asap. My plan was to charge up to 100% and record the miles value in the car but tomorrow I am working from home as it happens so it will have to be Monday. Interesting though that this change kick off after my visit on SC and the replacement of these parts. I wonder if it is valid to check on lets say 50% and extrapolate.
Thanks for the feedback. I will do this asap. My plan was to charge up to 100% and record the miles value in the car but tomorrow I am working from home as it happens so it will have to be Monday. Interesting though that this change kick off after my visit on SC and the replacement of these parts. I wonder if it is valid to check on lets say 50% and extrapolate.
It is probably just that the BMS was reset as part of the repairs, and it now has to re-learn the actual current capacity of your battery. So please report back after some time has passed so we can see what has happened.
I had some service done a few days ago on my model 3 and asked the service rep how to best balance the battery and how to change it. He told me to leave it for a couple of days setting the limit to 80%. In this wayevery time the charge drops a few percent and charging to 80% restarts the battery cells thart were not filled last time will have an additional chance to get filled. This is pretty much what I always do, except maybe not for a couple of days all the time. However I have noticed no difference since trying this out.
I've also tried letting the car sleep for a couple of hours and still no change. On the contrary as cold weather is approaching my estimated range is falling even more. Now it has fallen from close to 500 km as new to about 460 with 45000 km driven. Not horrible, but still more than half of the compared cars according to the Stats app.
Lots of guesstimation involved in this ;(
I've also tried letting the car sleep for a couple of hours and still no change. On the contrary as cold weather is approaching my estimated range is falling even more. Now it has fallen from close to 500 km as new to about 460 with 45000 km driven. Not horrible, but still more than half of the compared cars according to the Stats app.
Lots of guesstimation involved in this ;(
DarkNightP3D
Member
So, I have been experimenting with similar charging behaviors as the ones described in this post. I’ll let my car sit overnight in my garage at anywhere from 20%-80% without charging, then letting the car charge to 70-90%. I vary the charging. It’s brought back 6-8 miles of range from my all time low at 100% which was a displayed 284 miles. However, even when running my car from a claimed “100%” SOC, to it showing 2km left I only used 66kWh of energy. This is in one drive cycle, with no stopping. So there wasn’t a bunch of energy used while the vehicle was in park or sitting, since I know some people may think that’s where the other bit of juice went...
anyway, in my mind that’s a 10% reduction in pack capacity vs. what I have understood to be a full discharge (should be 72-74kwh), let’s call it 73kWh. I have a little over 30,000 miles on my car now, but the displayed range hasn’t really changed any in the past 11 months. All my “degradation” occurred from August 2019 to January 2020 (first 5 months of ownership). My local SC has said my pack capacity is within the range of all other M3 Packs. I drive a lot of long distance trips where there’s sometimes infrequent Superchargers. A 10% reduction of range on a P3D+ Can be the difference in getting to a charger or not.
anyway, in my mind that’s a 10% reduction in pack capacity vs. what I have understood to be a full discharge (should be 72-74kwh), let’s call it 73kWh. I have a little over 30,000 miles on my car now, but the displayed range hasn’t really changed any in the past 11 months. All my “degradation” occurred from August 2019 to January 2020 (first 5 months of ownership). My local SC has said my pack capacity is within the range of all other M3 Packs. I drive a lot of long distance trips where there’s sometimes infrequent Superchargers. A 10% reduction of range on a P3D+ Can be the difference in getting to a charger or not.
AlanSubie4Life
Efficiency Obsessed Member
For a 2018/2019 3P+, you should expect for a full discharge from 290 rated miles to 0 rated miles:
290rmi*245Wh/rmi*0.955*0.99 =67.2kWh
This accounts for the 4.5% buffer (which you may be able to use in a pinch if you drive really slowly, but is not recommended - but is used completely in the EPA range test) and the ~1% inaccuracy of the trip meter (heat loss or whatever it is).
So your result to ~1rmi makes sense. Had to assume you started at 290rmi since you did not say.
But it is very close to what you observed.
Your battery capacity is 71kWh, 290rmi*245Wh/rmi, down from a starting energy of about 78kWh. Very normal for 2 years old with 20-30k miles or similar; 9% loss.
Aside:
For those people trying the method on the first post, be sure to get a 12V monitor device to be able to make sure your car is sleeping correctly - or change your password to disable ALL third party apps. At least with Stats, it is impossible to implement the long sleep strategy outlined, as the car is woken up every hour or so.
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I’ve been reading your post on several occasions since you first placed it and have grown more comfortable watching my M3 2019 siphon it’s range from 310 to 299 after the first 3 months, then to 285 by February, returning to 295 by mid august and then in 24 hours last week dropping to 271 where it stands now exactly 1 year after purchase.
Although I have diligently read reports about the BMS and it’s resetting, I cannot help seeing one glaring effect that supersedes the BMS: The Temperature.
Case in point. All of the sudden drops in 100% range for me happened when the temperature dropped below 50 deg Fahrenheit. The last drop from 285 to 270 occurred overnight when the car was left outside and the temperature dropped to 38 degrees prompting the use of the heater. It has stayed at 268-273 since the temps are in the 40’s on a daily basis.
My stats app data seems to back this up also, showing the drops occurring in the winter months, corresponding to its defined parameter - Efficiency (which seems to decrease once the heater is activated, regardless of speed), with a concomitant rise in the efficiency number in the spring and summer months with the decreased use of the heater.
Can you share your thoughts on this phenomenon? I think your Data is showing similar fluctuations around the calendar.
Thanks.
AlanSubie4Life
Efficiency Obsessed Member
Ignore the data from Stats app, since it uses a different API value to figure out the projected range. This comes into play when temperatures are cold.
The other API value that is available is also dependent on temperature, but a lot less so. You might see variation of 10 miles out of 300 miles from summer temps to winter temps. @KenC has published some comparative plots on this, showing the difference as the seasons change.
You'll really see the massive discrepancy between the two API values show up when the blue snowflake shows up. That's when the Stats projected range will go through the floor, while the 100% range reported by the Tesla app will not be impacted as much.
Not clear which app the values you are reporting here are from. (Tesla or Stats)
It's all theoretical for me, since I live in San Diego.
Presumably the BMW was r
Anyway, here's my exported Stats data overlaid with ambient temps. The Stats data is blue, the temp is red. Notice the correlation. Also note the blue outlier dots are blue snowflake days.:
As @AlanSubie4Life notes, I've posted my Stats data quite a few times to illustrate that 3rd-party apps like Stats and TeslaFi use the SOC api that does not account for temperature. The net result is that your ESTIMATED rated range can vary up to 14 miles, based upon temps. Or at least mine does. You know that Stats and TeslaFi don't account for temp, since on blue snowflake days, the estimated rated range is far below normal, as much as 30miles lower.
Anyway, here's my exported Stats data overlaid with ambient temps. The Stats data is blue, the temp is red. Notice the correlation. Also note the blue outlier dots are blue snowflake days.:
Investor since 2012, owner since 2018 - MR 3. I've read this thread and others, I know there is battery degradation, BMS calculations, but my car used to get 260, then 244, now 233. I'm really ****ing tired of the continual drop and just ready to give up trying to understand. Not happy as it puts more stress on cross country diving than in the beginning, but nothing i can do....
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