First 10k miles Model Y Long Range battery degradation less than 2 miles

Hello everyone,

I benefited a lot from other posters in this forum, so thought I'd give back by sharing my personal experience. Earlier today I charged to 100% for the first time in months just in order to see what the actual range is rather than one extrapolated from lower states of charge. Yes, I know that even with this approach the reading can be off, but I surmise that if the reading is 328.14 or 328.48, the precise range likely rounds to 328.

Here's the historical chart from TeslaFi showing calculated range from December last year, 3 months after I took delivery of my Model 3 LR. Interestingly, the battery shows no incremental degradation throughout the entire period that we have data for.

Over the 9 months and 10k miles, about half of the charging was from 50 kW DCFC stations. About 10% was supercharging, and 40% was Level 2 charging. I typically charged to around 70%-90% then ran the battery down. A few times I did charge to over 90% immediately before a lot of driving. Whenever I left the car at rest for a few days or longer, I made sure it had around 60% battery or less. So even though I charged to high SoC's often, the car didn't spend much time at over 60% SoC. Also, it's been a long and cold winter in LA, so storage temperatures have been very favorable.

Because I have a long work commute, and because I don't use home charging, I think I have relatively deep charge-discharge cycles, probably around 50%. I'm sure after a lot more miles this will catch up to me, but for now it's quite clear that calendar aging plays a much larger role.

Happy to answer any questions about charging habits. Otherwise, I think I'm an example of how keeping a Tesla at a low SoC is very effective in minimizing battery degradation.

 

[Hiline]

Heads up to anyone following this thread. I'm going to be on a road trip for the next 2 weeks, covering around 3k miles, so I'm going to rely on Superchargers a lot. My plan is to charge from under 10% to 80% each time - this seems to be good practice to minimize battery degradation. I'm going to report back degradation after the trip, so we can see what the impact of cyclic aging + supercharging looks like on the battery.

 

[HMHM]

I typically charged to around 70%-90% then ran the battery down. A few times I did charge to over 90% immediately before a lot of driving. Whenever I left the car at rest for a few days or longer, I made sure it had around 60% battery or less. So even though I charged to high SoC's often, the car didn't spend much time at over 60% SoC

Great progress! It is encouraging to read your perspective. Your charging habit is significantly different from a generally accepted practice, but your degradation is fairly low. Thanks for sharing!

 

[Pianewman]

Hiline: Battery degradation isn't accurately measured using miles, as that is dependent on your driving habits. You must be driving in a manner matching EPA's expectation.

Battery degradation is measured using Teslafy, or Tessie, or following the instructions in this YouTube, which takes 24 hours:

 

[zroger73]

I installed Tessie last weekend. I don't know how accurate it is, but it reported a 0.2% degradation on my 2.5 month-old, 3,500-mile MYLR after the first charge. After the second charge, it shows 0% degradation. I normally charge to 60% each day then charge again at 45-50% which is all I need for my 30-50 miles of daily driving.

 

[Hiline]

Hiline: Battery degradation isn't accurately measured using miles, as that is dependent on your driving habits. You must be driving in a manner matching EPA's expectation.

Battery degradation is measured using Teslafy, or Tessie, or following the instructions in this YouTube, which takes 24 hours:

If original battery capacity and current battery capacity are both measured on EPA standards, then it doesn't matter, does it? The 2-mile battery degradation was already rounded.

 

[Iron]

I think that 10K is a little too soon to be trying to build a good picture of the battery degradation trend of a vehicle. I do agree that keeping a low SOC is probably the best route to go though, so keep up the good work.

I charge to 60% which completes 20 min before I leave for work. Get to work and it's about 52% sitting all day. Get home and it's about 44% where it sits overnight till the early morning leave by charging kicks in again. Both parking locations are indoor, so the car doesn't sit out in the sun much. I do plan to do a charge up to 95% soon, then let it sleep for 3 hours, just so it can resync the BMS. I don't plan on doing 100% unless forced to.

 

[Hiline]

Something strange happened. After a few supercharging sessions my estimated range dropped precipitously. It went from 328 miles straight down to 318 miles and has been staying there since. Could 318 be the more accurate estimate?

 

[Pianewman]

I'm not a bit surprised. Reality check. Your 10k analysis, for whatever reason, just didn't make any sense.

Sorry for the rude "reality check", but I think your efficiency number is now more accurate.

 

[s7gpt]

Something strange happened. After a few supercharging sessions my estimated range dropped precipitously. It went from 328 miles straight down to 318 miles and has been staying there since. Could 318 be the more accurate estimate?

View attachment 952302

same here, interested in other comments...

 

[Mrbrock]

Something strange happened. After a few supercharging sessions my estimated range dropped precipitously. It went from 328 miles straight down to 318 miles and has been staying there since. Could 318 be the more accurate estimate?

View attachment 952302

You mentioned only using 10% SC before and I think the high amp DCFC has something to do with how the BMS accurately calculates range. Here is my battery graph with the red lines being supercharging trips, otherwise all L2. No SC for the first 3500 miles and then a big drop immediately after but I was still keeping in the charge every day up to 90% and never gave the car a chance to take readings at varying SoC. There is a drop after every trip with SC. After I got down to 290 range I used the tips in battery degradation thread to get it back to the expected range and it seems more consistent now. The most recent one popped right back up within a couple charges. Once you are done with your trip and get back to you old charging habits it will be interesting to see if it reverts back to your old state or continues to move towards the fleet average.

 

[Hiline]

I have concluded my road trip and this is where my reported battery degradation stands after 3k+ miles of supercharging. I don’t think supercharging could impact range so severely, but I’m open to any possibility.

I’m going to report back after reverting to my old charging habits.

 

[Mrbrock]

View attachment 953972

I have concluded my road trip and this is where my reported battery degradation stands after 3k+ miles of supercharging. I don’t think supercharging could impact range so severely, but I’m open to any possibility.

I’m going to report back after reverting to my old charging habits.

Yep, just make sure to leave it overnight sleeping at various SOCs and it will give the BMS better numbers. Hopefully you will see it jump back up but who knows.

 

[tampaboyt]

how are you getting these graphs? I don't see anything in the Tesla energy section

 

[boulder.dude]

Since the degradation/EPA range numbers are all estimated by the BMS, it looks like SC charging affects the estimate, but does not actually cause immediate degradation. Great data.

I joined the low SOC club about 6 months ago after a year of mistakenly following advice on TMC (and implications in the Tesla manual) to “plug in every night and charge to 70 or 80.”

 

[CaseyL]

how are you getting these graphs? I don't see anything in the Tesla energy section

That graph is from Teslafi. You sign up for $50 a year. Teslafi (and others) continually log data from your car.

 

[Hiline]

Since the road trip, I've had the car sleep at 38%, 20%, and 73% SoC. Rated range has continued to drop. I'm going to expand the SoC range for sleeps over the next few days and see if the BMS changes range readings.

 

[Mrbrock]

Since the road trip, I've had the car sleep at 38%, 20%, and 73% SoC. Rated range has continued to drop. I'm going to expand the SoC range for sleeps over the next few days and see if the BMS changes range readings.

View attachment 954829

How long are these sleeps? Do you have the force sleep option checked on teslafi? I think you also need to do a charge to 95 or 100 to force the battery to load balance. Here are my charges from when I hit rock bottom range on 12/12/22 at 290 miles and 2/24/23 when I hit 316.

 

[Hiline]

How long are these sleeps? Do you have the force sleep option checked on teslafi? I think you also need to do a charge to 95 or 100 to force the battery to load balance. Here are my charges from when I hit rock bottom range on 12/12/22 at 290 miles and 2/24/23 when I hit 316.

View attachment 955071
View attachment 955073

The sleeps were overnight, so varied between 7 hours and 17 hours. I didn't ask TeslaFi to put my Tesla to sleep, but it recorded these overnight sleeps.

I notice you had a bunch of charges to the top SoC range. I think I'm gonna charge to 100% at some point this week to see if that moves the needle.

 

[Mrbrock]

The sleeps were overnight, so varied between 7 hours and 17 hours. I didn't ask TeslaFi to put my Tesla to sleep, but it recorded these overnight sleeps.

I notice you had a bunch of charges to the top SoC range. I think I'm gonna charge to 100% at some point this week to see if that moves the needle.

It won’t balance cells unless it’s at 100%. It can’t provide good calculations if the cells are unbalanced. Supercharging is so fast that it doesn’t have time to do any of this so it occasionally needs to be balanced. And multiple supercharging sessions tend to make them more unbalanced, I think. As far as sleeping, that looks good. I know many people think their car sleeps but they use their app all the time and it constantly wakes the car up if it’s within bluetooth range. The teslafi option seems to prevent this, to the point of making it a bit harder to wake up after a long sleep but you know it will stay sleeping so I prefer that.