Question on battery capacity and range

[A_L.]

I have an SR Model y and my range has been getting worse for the last month not sure why. I have tried driving more economically and still docent help. my range meter use to show 244 miles on full or 220 miles at 90% now it shows 209 miles at 90% and 233 miles on full. I changed to to percentage cause I thought that would help but the battery dosent seem to want to hold at 90%. After unplugging the battery drops down almost immediately to 89%. For those who have an SR Model y what your range? im getting no where near 200 miles. im getting closer to 180 miles at 90% that's what the energy app shows. Also this might seem weird I know as an SR my y won't use the 250kwh charging speeds but when I first got my Y and I went to a supercharger I was getting those speeds! and now I don't.

 

[angus[Y]oung]

Welcome aboard, @A_L.

I think you haven't gotten any replies yet because there are already dozens of threads on these topics. You may want to do some searching in the Model Y: Battery & Charging and Model Y areas for lots of good discussion. At a high level:

• Actual range depends on many variables, including but not limited to things like the weather, your driving style, elevation changes, head/tail winds, your driving speed (the faster you go on the freeway for example, the more dramatically your range will decrease), and many other factors.
  • At least some of these factors should be taken into account in the Energy app, which is why it is showing you a lower range than the EPA rating for an SR MY. This is normal.
• The range that you toggled from miles to percentage (good move, the community generally recommends this for peace of mind) does not reflect any of those things I listed above. That number of miles is based on the EPA's estimated range and multiplied by your remaining battery percentage (also known as State Of Charge, often listed as SOC here in the community).
  • However, over time, the battery management system (BMS) in the car can get "out of sync" with how much SOC you actually have. This is for a variety of reasons I won't go into here. Chances are that the reduction you've observed in the main battery display isn't a result of loss of actual range (though it can be partially that), but more likely the BMS being a bit off. There are ways you can "reset" this number and regain some/most/all of that "lost" range. Do some searching for more details.
• re: Supercharging. 250kW is the absolute max you would ever see, but:
  • Only at a V3 supercharger.
  • If you were at a V2 supercharger, the max you would ever see would be 150kW, and much less if you're sharing a shared stall with someone (for example: you're on 1A and they're on 1B or vice versa, same with 2A and 2B, and so on). Try not to park right next to another vehicle at a V2 supercharger unless there are no open unshared stalls, as both you and the car you share a transformer with will see much slower charging rates. This may be unavoidable if the supercharger site is busy at the time.
  • For V3 superchargers the power is not shared even if the stalls are numbered 1A, 1B, 1C, 1D you're fine.
  • At an "urban" supercharger, the most you would see would be 72kW.
  • This peak number (250/150/72) is not what you will see every time, nor for the whole time.
  • There is a charging "curve", where you will see highest rates near the beginning of your charge, and it will taper downward from there.
  • Charging rate (kW speed) depends on the state of charge your car is at. So if you pull up with a fairly full battery, the rate you will see will be much less than the peak. If you pull up with 10% or less, you're going to see a very high rate at first and it will taper as your battery gets closer to full.
  • It also depends on your battery's temperature. To get the best charging rate, your battery needs to be in a specific temperature range. Next time, try setting the supercharger you want to use as your destination in the navigation system, and as you get close to the supercharger, you will see a notice on your screen that the BMS is preconditioning the battery for supercharging. This will help ensure you get the best possible kW for your SOC that's possible.

Overall these topics are very nuanced but there is a ton of info out there, especially here in the TMC community. Please take some time to explore and you will learn a lot. Also: read your owner's manual https://www.tesla.com/sites/default/files/model_y_owners_manual_north_america_en.pdf as it contains lots of great info on range and how to maximize it in various driving conditions, as well as on charging and many other topics.

 

[iamnid]

Welcome aboard, @A_L.

I think you haven't gotten any replies yet because there are already dozens of threads on these topics. You may want to do some searching in the Model Y: Battery & Charging and Model Y areas for lots of good discussion. At a high level:

• Actual range depends on many variables, including but not limited to things like the weather, your driving style, elevation changes, head/tail winds, your driving speed (the faster you go on the freeway for example, the more dramatically your range will decrease), and many other factors.
  • At least some of these factors should be taken into account in the Energy app, which is why it is showing you a lower range than the EPA rating for an SR MY. This is normal.
• The range that you toggled from miles to percentage (good move, the community generally recommends this for peace of mind) does not reflect any of those things I listed above. That number of miles is based on the EPA's estimated range and multiplied by your remaining battery percentage (also known as State Of Charge, often listed as SOC here in the community).
  • However, over time, the battery management system (BMS) in the car can get "out of sync" with how much SOC you actually have. This is for a variety of reasons I won't go into here. Chances are that the reduction you've observed in the main battery display isn't a result of loss of actual range (though it can be partially that), but more likely the BMS being a bit off. There are ways you can "reset" this number and regain some/most/all of that "lost" range. Do some searching for more details.
• re: Supercharging. 250kW is the absolute max you would ever see, but:
  • Only at a V3 supercharger.
  • If you were at a V2 supercharger, the max you would ever see would be 150kW, and much less if you're sharing a shared stall with someone (for example: you're on 1A and they're on 1B or vice versa, same with 2A and 2B, and so on). Try not to park right next to another vehicle at a V2 supercharger unless there are no open unshared stalls, as both you and the car you share a transformer with will see much slower charging rates. This may be unavoidable if the supercharger site is busy at the time.
  • For V3 superchargers the power is not shared even if the stalls are numbered 1A, 1B, 1C, 1D you're fine.
  • At an "urban" supercharger, the most you would see would be 72kW.
  • This peak number (250/150/72) is not what you will see every time, nor for the whole time.
  • There is a charging "curve", where you will see highest rates near the beginning of your charge, and it will taper downward from there.
  • Charging rate (kW speed) depends on the state of charge your car is at. So if you pull up with a fairly full battery, the rate you will see will be much less than the peak. If you pull up with 10% or less, you're going to see a very high rate at first and it will taper as your battery gets closer to full.
  • It also depends on your battery's temperature. To get the best charging rate, your battery needs to be in a specific temperature range. Next time, try setting the supercharger you want to use as your destination in the navigation system, and as you get close to the supercharger, you will see a notice on your screen that the BMS is preconditioning the battery for supercharging. This will help ensure you get the best possible kW for your SOC that's possible.

Overall these topics are very nuanced but there is a ton of info out there, especially here in the TMC community. Please take some time to explore and you will learn a lot. Also: read your owner's manual https://www.tesla.com/sites/default/files/model_y_owners_manual_north_america_en.pdf as it contains lots of great info on range and how to maximize it in various driving conditions, as well as on charging and many other topics.

Good points and it's most likely just the BMS incorrectly stating the remaining miles. BUT, I believe you are incorrect about the max charging rate at a V3 supercharger. Since OP has the SR model Y, I think the max charge rate is 150kW (or thereabouts) not the 250kW enjoyed by LR and Performance models

 

[MD-2000]

I have an SR Model y and my range has been getting worse for the last month not sure why. I have tried driving more economically and still docent help. my range meter use to show 244 miles on full or 220 miles at 90% now it shows 209 miles at 90% and 233 miles on full. I changed to to percentage cause I thought that would help but the battery dosent seem to want to hold at 90%. After unplugging the battery drops down almost immediately to 89%. For those who have an SR Model y what your range? im getting no where near 200 miles. im getting closer to 180 miles at 90% that's what the energy app shows. Also this might seem weird I know as an SR my y won't use the 250kwh charging speeds but when I first got my Y and I went to a supercharger I was getting those speeds! and now I don't.

I found advice online (on this board) and the Tesla repair guy backs up this recommendation:

i used to plug my 3LR-AWD as soon as I got home. From Dec 2018 to recently the 80% range dropped from 396 to 360 to 332.
The car will do period battery assessments" - there is no simple "how full?" indicator for a battery. It tries to figure out from the charge it sees how much of 100% you battery has.

To properly assess your battery - charge to your standard max (80% or 90%) then unplug it and leave it unplugged as long as possible before using it.
Every so often, run the battery down to 20% or less, and let it sit like that - again unplugged - as long as you can.
When the car has done battery assessments at high and low, it has a better idea of what you battery capacity actually is.

I've found with this that my battery now charges between 375km and 394km at 80%.

of course, like gasoline mileage ratings, this is a suggestion only. I've had urban stop-and-go driving at -20C where I used 3 or 4km for each 1km travelled (avg trip speed 25km/h), and used 10% extra (11km per 10km travelled) in hot weather at 116km/h, 4km used for every 3km travelled at 20C with a good headwind at 105km/h.

So as the guys on TV say "Your mileage may vary..." At least, as I understand, cabin heat and AC are much more efficient in the Y.