How I Recovered Half of my Battery's Lost Capacity

[Candleflame]

Ill be the next one. My car sits a lot at 50 to 70 percent but ive let it sit at varying percentages over the last few weeks so we will see and ill report back.

Deep cycling the battery with hivh recharge while on a road trip did improve range for me as per my previous post but only by about 2 to 3km. I presume this is due to quicker/easier pack balancing.

Baring in mind i only have around 5.5 percent degradation. Though most of that didnt happen gradually but overnight which make me think its a bms thing...

 

[IDRVSLO]

I tried this and the needle didn’t move for me so far. My car usually sits at home without sentry mode on and I don’t have any 3rd party apps that would keep the car awake. For the last 5 weeks I’ve been charging when the car gets down between 10-30% SOC to a charge between 50% and 80% once a week and finally to 95%. Each time the car sat without being disturbed for hours on end since it’s covid time. I started this with a max range of 282 miles and today it reads 280 . Going to keep trying this regardless to see what happens. Oh yeah I picked up my performance 3 in March with a max of 299.

 

[toolman335]

I tried this and the needle didn’t move for me so far. My car usually sits at home without sentry mode on and I don’t have any 3rd party apps that would keep the car awake. For the last 5 weeks I’ve been charging when the car gets down between 10-30% SOC to a charge between 50% and 80% once a week and finally to 95%. Each time the car sat without being disturbed for hours on end since it’s covid time. I started this with a max range of 282 miles and today it reads 280 . Going to keep trying this regardless to see what happens. Oh yeah I picked up my performance 3 in March with a max of 299.

Sorry to hear this! It seems like what works for some doesn't work for others. I hope that as time goes on that we can get more information behind this "science."

 

[N54TT]

I’ve had my p3d+ for just over 2 yrs 26k miles. The end of July I happened to start doing this method before the OP started this thread. I stopped charging everyday and only charged when it was 20-30%....letting the car sit/sleep at those low SOC for at least 2-3hrs before charging back up to 90% and letting it sit at 90% for a few hrs. I don’t use sentry mode...so it’s always off. I went from plugging in daily to only charging every 4-6 days. My 90% went from 248 to now 260.

Takeaways from my experience:
1) I’ve done 15 deep charging cycles since I started end of July and only got to 260 with my last two charges....so it can take some time depending on how many miles you drive.
2) caused some range anxiety that I never had before. I’m the never let my gas tank get below 1/4 kind of guy. With having a varying work/kids/family schedule there’s been times I would have to calculate and plan for how far I might be driving to make sure I had enough SOC to get through my day/trip.
3) confirmed my lack of desire to drive at low SOCs. One of the main reasons I bought the car was for the acceleration. There’s a noticeable drop in power at lower SOC (as seen by MPP’s dyno testing) and is one of the reasons I prefer plugging in everyday. Last night I ran into a modified e92 m3 on the highway and had some friendly pulls. With only 50% SOC it left me wondering how it would have compared if I had a higher SOC.

Not sure how much longer I can keep this up...but at this point I have to keep going until the range levels off lol.
Here’s a screen shot from STATS showing calculated 100%

 

[toolman335]

I’ve had my p3d+ for just over 2 yrs 26k miles. The end of July I happened to start doing this method before the OP started this thread. I stopped charging everyday and only charged when it was 20-30%....letting the car sit/sleep at those low SOC for at least 2-3hrs before charging back up to 90% and letting it sit at 90% for a few hrs. I don’t use sentry mode...so it’s always off. I went from plugging in daily to only charging every 4-6 days. My 90% went from 248 to now 260.

Takeaways from my experience:
1) I’ve done 15 deep charging cycles since I started end of July and only got to 260 with my last two charges....so it can take some time depending on how many miles you drive.
2) caused some range anxiety that I never had before. I’m the never let my gas tank get below 1/4 kind of guy. With having a varying work/kids/family schedule there’s been times I would have to calculate and plan for how far I might be driving to make sure I had enough SOC to get through my day/trip.
3) confirmed my lack of desire to drive at low SOCs. One of the main reasons I bought the car was for the acceleration. There’s a noticeable drop in power at lower SOC (as seen by MPP’s dyno testing) and is one of the reasons I prefer plugging in everyday. Last night I ran into a modified e92 m3 on the highway and had some friendly pulls. With only 50% SOC it left me wondering how it would have compared if I had a higher SOC.

Not sure how much longer I can keep this up...but at this point I have to keep going until the range levels off lol.
Here’s a screen shot from STATS showing calculated 100%

View attachment 595808

You led into my next question:
If/when we get our range up to where we'd like it to be, what is the best way to keep that range where it is? Do we have to drive like this forever?
I completely agree that I don't enjoy running the car to a low SOC.

 

[N54TT]

You led into my next question:
If/when we get our range up to where we'd like it to be, what is the best way to keep that range where it is? Do we have to drive like this forever?
I completely agree that I don't enjoy running the car to a low SOC.

That’s a good question. I’ve done a few deep discharges in the past and didn’t see any increases. This time I decided to stick it out and try it longer. It’s been a painful 2 months lol. I’m just going to go back to my usual charging habits once it levels off. At least I know after two years...what my real degradation is really like. Maybe do it again next year or two? Depending on what my stated miles drop to. Something to keep in mind as well, is that while this type of charging habit can lead to more accurate displayed range...deep discharges aren’t what’s best for longevity of the cells.

 

[Zoomit]

deep discharges aren’t what’s best for longevity of the cells.

Thanks for summarizing your experience.

I wouldn't say that discharging down to 20-30% qualifies as a "deep discharge" that would harm the cells. In fact, in the document Tesla submits to the EPA, they state that it's best to store battery packs at a SOC between 15 and 50%.

 

[Candleflame]

Thanks for summarizing your experience.

I wouldn't say that discharging down to 20-30% qualifies as a "deep discharge" that would harm the cells. In fact, in the document Tesla submits to the EPA, they state that it's best to store battery packs at a SOC between 15 and 50%.

can we read those documents somewhere?

15-50% makes sense as this is essentially 20% - 55% which is what we all know already.

 

[Zoomit]

can we read those documents somewhere?

15-50% makes sense as this is essentially 20% - 55% which is what we all know already.

Sure, the Tesla documentation (page 17) to the EPA states:

“To maintain service life, the battery pack should be stored at a state of charge (SOC) of 15% to 50%.”

If you asume that refers to actual SOC for a battery pack, not indicated SOC, then that would translate to about 11% to 48% indicated SOC to account for the 4.5% bottom buffer.

 

[N54TT]

Thanks for summarizing your experience.

I wouldn't say that discharging down to 20-30% qualifies as a "deep discharge" that would harm the cells. In fact, in the document Tesla submits to the EPA, they state that it's best to store battery packs at a SOC between 15 and 50%.

Sorry, what I was trying to say is that those full cycles are harsher on lithium ions than partial cycles. I agree with it being best to store around 50%...that’s what was always suggested for 18650 cells I’ve had for years in my Fenix lights. 15% seems too low for storage though.

 

[Candleflame]

Sure, the Tesla documentation (page 17) to the EPA states:

“To maintain service life, the battery pack should be stored at a state of charge (SOC) of 15% to 50%.”

If you asume that refers to actual SOC for a battery pack, not indicated SOC, then that would translate to about 11% to 48% indicated SOC to account for the 4.5% bottom buffer.

good question im not sure if it refers to displayed SOC or true SOC.
I DO have a feeling that storing a Tesla at deep discharge actually does not harm to the battery at all as long as you dont let any cell get below 0.1%. We also know that there are quite a few owners in the USA who supercharge frequently and keep cycling the battery betwen <5% and 60% for superfast charging without negative sequelae. Certainly from the info we have on lithion ion batteries we know that low SOC actually isnt harmful as long as it is not 0% and certainly cycling i.e. 60% to 5% is better than 80% to 25% for longevity.
It makes hence sense that Tesla advises not to drop below 10% in case of some self discharge over storage. And we know from Model S that apparently the old batteries do have a risk of undervolting under load if the car is below 10%.

 

[Candleflame]

Thanks for summarizing your experience.

I wouldn't say that discharging down to 20-30% qualifies as a "deep discharge" that would harm the cells. In fact, in the document Tesla submits to the EPA, they state that it's best to store battery packs at a SOC between 15 and 50%.

Like I wrote in the post above this one, there is only very little evidence (including from Teslas which have sat at <5% SOC in parking lots/scrap yards) that the battery gets harmed at all from sitting at <5% even for prolonged periods of time. It certainly seems to be better to sit at 5% than to sit at 95% particularly if it gets hot. So storage probably isnt the issue.
The SOC is just an arbitary marker of cell voltage anyway what really matters is that cells dont dip below voltage they would normally have at 0% as this causes irreversible reactions.

Where there is a problem though is if you drive on the german autobahn and flog the car at 160km/h and overtake BMWs while flooring it for extended periods of such high speeds while it is less than 20% SOC there is a chance that individual cells DO drop below a certain voltage where harm can occur to the battery, which is also why Tesla limits acceleration below 10%. However, im sure there are rather non conservative and limit it less than they really should.
I usually put my car in chill mode below 15%.

 

[sa012]

I’ve had my p3d+ for just over 2 yrs 26k miles. The end of July I happened to start doing this method before the OP started this thread. I stopped charging everyday and only charged when it was 20-30%....letting the car sit/sleep at those low SOC for at least 2-3hrs before charging back up to 90% and letting it sit at 90% for a few hrs. I don’t use sentry mode...so it’s always off. I went from plugging in daily to only charging every 4-6 days. My 90% went from 248 to now 260.

Takeaways from my experience:
1) I’ve done 15 deep charging cycles since I started end of July and only got to 260 with my last two charges....so it can take some time depending on how many miles you drive.
2) caused some range anxiety that I never had before. I’m the never let my gas tank get below 1/4 kind of guy. With having a varying work/kids/family schedule there’s been times I would have to calculate and plan for how far I might be driving to make sure I had enough SOC to get through my day/trip.
3) confirmed my lack of desire to drive at low SOCs. One of the main reasons I bought the car was for the acceleration. There’s a noticeable drop in power at lower SOC (as seen by MPP’s dyno testing) and is one of the reasons I prefer plugging in everyday. Last night I ran into a modified e92 m3 on the highway and had some friendly pulls. With only 50% SOC it left me wondering how it would have compared if I had a higher SOC.

Not sure how much longer I can keep this up...but at this point I have to keep going until the range levels off lol.
Here’s a screen shot from STATS showing calculated 100%

View attachment 595808

From my understanding the StatsApp doesn't truly let your car sleep for long periods of times. I had emailed about it and was told that the StatsApp checks with the car almost every hour. Have others heard different?

 

[KenC]

good question im not sure if it refers to displayed SOC or true SOC.
I DO have a feeling that storing a Tesla at deep discharge actually does not harm to the battery at all as long as you dont let any cell get below 0.1%. We also know that there are quite a few owners in the USA who supercharge frequently and keep cycling the battery betwen <5% and 60% for superfast charging without negative sequelae. Certainly from the info we have on lithion ion batteries we know that low SOC actually isnt harmful as long as it is not 0% and certainly cycling i.e. 60% to 5% is better than 80% to 25% for longevity.
It makes hence sense that Tesla advises not to drop below 10% in case of some self discharge over storage. And we know from Model S that apparently the old batteries do have a risk of undervolting under load if the car is below 10%.

My Tesla was home delivered with ZERO SOC, at the end of the day in Winter. The driver said he loaded it that way in the morning. Of course, since it was winter, the driver couldn't drive down my dirt road, so we met at a rest stop to exchange cars. The rest stop the driver chose had no chargers! We had to reload the Tesla and take it to a rest stop with a supercharger. The car was so dead, I actually pushed it to get it back onto the carrier.

Good thing is my battery seems to have survived no worse for the wear.

Starting to charge from Zero.

 

[Arctic_White]

good question im not sure if it refers to displayed SOC or true SOC.
I DO have a feeling that storing a Tesla at deep discharge actually does not harm to the battery at all as long as you dont let any cell get below 0.1%. We also know that there are quite a few owners in the USA who supercharge frequently and keep cycling the battery betwen <5% and 60% for superfast charging without negative sequelae. Certainly from the info we have on lithion ion batteries we know that low SOC actually isnt harmful as long as it is not 0% and certainly cycling i.e. 60% to 5% is better than 80% to 25% for longevity.
It makes hence sense that Tesla advises not to drop below 10% in case of some self discharge over storage. And we know from Model S that apparently the old batteries do have a risk of undervolting under load if the car is below 10%.

Here is the thing: no one knows exactly how much extra the battery life is if you do 5% to 60% rather than 25% to 80%.

Will the battery last 10% more if you go 5 -> 60 rather than 25 -> 80? Does anyone really know?

All I know is that the battery is rated to last 500K miles and still retain 70% of its capacity. Meaning, at 800K kms, you still have 70% of your capacity (350 kms for LR AWD version). This assumes normal operation (doing 90% to 50% discharge).

Do you really plan on keeping your car for 500K miles?

What does it matter if you're replacing the car within 4 to 8 years like most folks who purchase new cars do?

 

[Arctic_White]

From my understanding the StatsApp doesn't truly let your car sleep for long periods of times. I had emailed about it and was told that the StatsApp checks with the car almost every hour. Have others heard different?

Car won't sleep only if the StatsApp is running in the background. If you close the app then it won't "ping" the car and let it go to sleep.

I have both the StatsApp and TeslaFi and my car sleeps regularly.

 

[toolman335]

Here is the thing: no one knows exactly how much extra the battery life is if you do 5% to 60% rather than 25% to 80%.

Will the battery last 10% more if you go 5 -> 60 rather than 25 -> 80? Does anyone really know?

All I know is that the battery is rated to last 500K miles and still retain 70% of its capacity. Meaning, at 800K kms, you still have 70% of your capacity (350 kms for LR AWD version). This assumes normal operation (doing 90% to 50% discharge).

Do you really plan on keeping your car for 500K miles?

What does it matter if you're replacing the car within 4 to 8 years like most folks who purchase new cars do?

Exactly. Everyone is acting disappointed that there's no million mile battery yet. Please. No one who bought this cutting edge technology vehicle will sit by idly in 4 years when similarly priced cars are blowing past 500 miles of range.
Every time I buy a new car I have a ten year plan. I have yet to make it past five.

 

[sa012]

Car won't sleep only if the StatsApp is running in the background. If you close the app then it won't "ping" the car and let it go to sleep.

I have both the StatsApp and TeslaFi and my car sleeps regularly.

Are you saying it will even let it sleep 3+ hours?? I know the car will sleep some with StatsApp, but from my understanding the car gets "pinged" about every hour which I would think wakes the car up.

 

[N54TT]

From my understanding the StatsApp doesn't truly let your car sleep for long periods of times. I had emailed about it and was told that the StatsApp checks with the car almost every hour. Have others heard different?

I close the app And only open it after charge is done to trigger it to capture the battery capacity reading...otherwise there’s too much variability depending if it’s on the lower or higher end of whole number. I have no issues with it waking the car and letting it sleep. If it does check the car every hour....it’s not waking it up. I’ve had issues with stats syncing certain charge data. Been escalated a bunch of times. he resets the server...it works for a bit and stops working again. I essentially use it to just track battery capacity and driving efficiency.

 

[Arctic_White]

Are you saying it will even let it sleep 3+ hours?? I know the car will sleep some with StatsApp, but from my understanding the car gets "pinged" about every hour which I would think wakes the car up.

Correct.

If you are able to close the app (I've an iPhone so I swipe up to close out of the app) then within an hour or so, the car will go to sleep. The car will remain asleep until I open the app (or the Tesla App) or approach the car and open one of the doors.

I didn't drive for one day and my car slept for 24+ hours as per TeslaFi.