Preconditioning & wh/mi & Range estimate on App & charging speeds

[Kaz93]

Hello everyone,

New to Tesla here! Just got my Model Y (Long range) and went on a long road trip 300 miles or so down and back a couple days later. When traveling down to my destination i had to stop at a supercharger that tesla recommended(Thousand oaks), about 5 minutes before arriving on the dashboard it read, "Preconditioning battery etc..." the location was Thousand Oaks. a couple days pass and i head back home and stop at the SAME supercharger inputting the same location into the navigation. Before arriving the "Preconditioning battery" did not come on at all? Is that normal? the temp was higher that day to maybe my regular driving heated the battery enough to accept a high rate of charge? I made sure that the navigation was going to a tesla supercharger to make sure it preconditioned the battery. Is this common ? or is it only when the car deems necessary that it will precondition a battery when input through tesla supercharger? Does preconditioning do nothing when temps are around 75?

Secondly, When arriving at the same supercharger on the second time (Thousand Oaks) i plugged in the car and the rate was half of what it was the first time i plugged in the car on the way down. The chargers there are the Gen 3 as it only has one charger coming from the stand. I plugged in the car and it said it would only charge to 80% because there were zero stalls left 24/24 had been taken when i pulled in. Is the rate of charge reduced when all stalls are taken? even with Gen 3? Also, it took significantly longer to charger because on average it was giving me 180 miles/hour.. vs 440 on my way down. Does the supercharging bill only account for how much energy is consumed into the car vs the time? because this charging trip took twice as long...

Lastly, on the trip back i was less worried about conserving energy and more focused on getting home from the long weekend. My speed stayed around 80+ even through some pretty high hills (Santa Barbara). As expected my WH/MI was significantly higher than my trip down. When plugging into my charger and setting the limit to 100 i noticed i lost about 3 miles of range from 100% as before? does Tesla use their 100% range indication based on recent driving style? or is this me losing battery range with a new vehicle? BTW i do not charge to 100 i was just interested in seeing if it had changed.

-Kaz

 

[jmaddr]

The chargers there are the Gen 3 as it only has one charger coming from the stand.

Did you visit the one at 4000 E Thosanf Oaks Blvd? Thousand Oaks, CA - East Thousand Oaks Boulevard Supercharger | Tesla
That one is listed as a 150kw supercharger which means v2 and stall sharing. Even v2 chargers have only a single charging cable. You hould be able to tell by looking at the bottom on the charger and if you see a marking that says a1 or c2 that’s how you know that you are sharing a stall. (A1 and A2 share the same 150kw for example). This should account for most of your drop. Now why you didn’t see the preconditioning happening I couldnt say.

 

[NCC81701]

Congrats on joining the club !

"Preconditioning battery etc..." the location was Thousand Oaks. a couple days pass and i head back home and stop at the SAME supercharger inputting the same location into the navigation. Before arriving the "Preconditioning battery" did not come on at all? Is that normal? the temp was higher that day to maybe my regular driving heated the battery enough to accept a high rate of charge? I made sure that the navigation was going to a tesla supercharger to make sure it preconditioned the battery. Is this common ? or is it only when the car deems necessary that it will precondition a battery when input through tesla supercharger? Does preconditioning do nothing when temps are around 75?

Preconditioning is based on temperature and in general it's to bring the temperatures of the battery up so it can accept the highest charging rate. If your batteries are warm enough it doesn't need to be pre-conditioned. Very broadly speaking Li-Ion batteries charges best between 15-35C (60-95F). I'm sure Tesla have dialed in a more specific range of temperature based on their battery chemistry and data history.

Secondly, When arriving at the same supercharger on the second time (Thousand Oaks) i plugged in the car and the rate was half of what it was the first time i plugged in the car on the way down. The chargers there are the Gen 3 as it only has one charger coming from the stand. I plugged in the car and it said it would only charge to 80% because there were zero stalls left 24/24 had been taken when i pulled in. Is the rate of charge reduced when all stalls are taken? even with Gen 3? Also, it took significantly longer to charger because on average it was giving me 180 miles/hour.. vs 440 on my way down. Does the supercharging bill only account for how much energy is consumed into the car vs the time? because this charging trip took twice as long...

As @jmaddr have pointed out, the charger at Thousand Oaks are 150kW chargers, so they are V2 chargers. A draw back of the V2 chargers is that 2 stalls share the same charging cabinet. If you look at the base of the super charger there should be a sign that says charger 3A and 3B for example. This means that these 2 stalls shares the same charging cabinet and if they are both occupied then the power is shared between both stalls (they are generally next to each other but it doesn't have to be). So if you arrive at a V2 charger, if you can you want to avoid charging next to someone that is already charging so you are not sharing a charging cabinet with someone to get the best charging speeds for both of you. The V3 superchargers have eliminated this problem that the V2 charger have for all except the most extreme cases.

Lastly, on the trip back i was less worried about conserving energy and more focused on getting home from the long weekend. My speed stayed around 80+ even through some pretty high hills (Santa Barbara). As expected my WH/MI was significantly higher than my trip down. When plugging into my charger and setting the limit to 100 i noticed i lost about 3 miles of range from 100% as before? does Tesla use their 100% range indication based on recent driving style? or is this me losing battery range with a new vehicle? BTW i do not charge to 100 i was just interested in seeing if it had changed.

The range estimate is based on the car's overly optimistic EPA rated consumption (~240W/mile) and charge/discharge history. There are always errors in measuring how much the battery have charge/discharge so how much energy is left in your battery pack is always an estimate based on how much the car thinks it had pulled out since the last charge and how much the car thinks it can put back into the battery the next time it hits the charger. I would not worry about not hitting the exact EPA range at 100% charge, being 2-3 miles off means the car's error of the amount of charge/discharge has happened is <1% which is perfectly reasonable. This is also how people can recalibrate the display range (and appear to re-gain some maximum range) by discharging down to ~0% and recharging to full. A 0-100% charge discharge cycle basically zeroes the charge/discharge logging errors it has accumulated over the the previous charge/discharge cycles. Battery degradation is a real thing though and I'd expect a normal degradation to be in the range of 5-10% over 100k Miles if the batteries weren't abused based on available ModelS/X data.

 

[pt19713]

Congrats on joining the club !

Preconditioning is based on temperature and in general it's to bring the temperatures of the battery up so it can accept the highest charging rate. If your batteries are warm enough it doesn't need to be pre-conditioned. Very broadly speaking Li-Ion batteries charges best between 15-35C (60-95F). I'm sure Tesla have dialed in a more specific range of temperature based on their battery chemistry and data history.

There's a range where the car will not precondition while navigating to a Tesla supercharger. I don't S/C often so I haven't been able to narrow it down, but it appears to be around 70-75F where the pack will not be preconditioned. The funny thing is, when you plug into the supercharger, both the front and rear Stator motors will warm up furiously, shutting off around when the battery pack is at 116F, and will continue to warm the battery pack to 131F.

Here are some screen shots showing assorted data in regards to the Stator motors, battery pack temps, etc during my last V3 session in colder temps

 

[pt19713]

I never knew what these 2 fields meant until this past supercharger session, which I commented above.

Once you're done with the session, the BMS will actively try and cool the pack down to 86F.

 

[GtiMart]

I've had my pack at 25C (77F) and navigating to a supercharger, it did precondition it until I arrived there, around 37C (98F) so I don't quite agree with one of your statements @pt19713 . I think the preconditioning target is higher than 70-75F. Otherwise yes, it continues to warm the battery as it charges.

 

[pt19713]

I've had my pack at 25C (77F) and navigating to a supercharger, it did precondition it until I arrived there, around 37C (98F) so I don't quite agree with one of your statements @pt19713 . I think the preconditioning target is higher than 70-75F. Otherwise yes, it continues to warm the battery as it charges.

There are a lot of variables so it's tough to narrow it down. My distance to the S/C was about 12 miles.

 

[Kaz93]

Did you visit the one at 4000 E Thosanf Oaks Blvd? Thousand Oaks, CA - East Thousand Oaks Boulevard Supercharger | Tesla
That one is listed as a 150kw supercharger which means v2 and stall sharing. Even v2 chargers have only a single charging cable. You hould be able to tell by looking at the bottom on the charger and if you see a marking that says a1 or c2 that’s how you know that you are sharing a stall. (A1 and A2 share the same 150kw for example). This should account for most of your drop. Now why you didn’t see the preconditioning happening I couldnt say.

Yes thats the one i visited, i guess i had a misunderstanding... i thought that only the Gen 3's had a single charger coming from the station. Thank you for the clarification.

 

[GtiMart]

Agreed. And I don't SC often either so I don't have great data.

 

[Kaz93]

There's a range where the car will not precondition while navigating to a Tesla supercharger. I don't S/C often so I haven't been able to narrow it down, but it appears to be around 70-75F where the pack will not be preconditioned. The funny thing is, when you plug into the supercharger, both the front and rear Stator motors will warm up furiously, shutting off around when the battery pack is at 116F, and will continue to warm the battery pack to 131F.

Here are some screen shots showing assorted data in regards to the Stator motors, battery pack temps, etc during my last V3 session in colder temps
View attachment 652326
View attachment 652327

Thank you for the data!

 

[Big Earl]

Hello everyone,

New to Tesla here! Just got my Model Y (Long range) and went on a long road trip 300 miles or so down and back a couple days later. When traveling down to my destination i had to stop at a supercharger that tesla recommended(Thousand oaks), about 5 minutes before arriving on the dashboard it read, "Preconditioning battery etc..." the location was Thousand Oaks. a couple days pass and i head back home and stop at the SAME supercharger inputting the same location into the navigation. Before arriving the "Preconditioning battery" did not come on at all? Is that normal? the temp was higher that day to maybe my regular driving heated the battery enough to accept a high rate of charge? I made sure that the navigation was going to a tesla supercharger to make sure it preconditioned the battery. Is this common ? or is it only when the car deems necessary that it will precondition a battery when input through tesla supercharger? Does preconditioning do nothing when temps are around 75?

The car will precondition when necessary based on battery temperature. If it's warm outside and/or you've driven for an extended period of time, preconditioning might not be necessary.

Secondly, When arriving at the same supercharger on the second time (Thousand Oaks) i plugged in the car and the rate was half of what it was the first time i plugged in the car on the way down. The chargers there are the Gen 3 as it only has one charger coming from the stand. I plugged in the car and it said it would only charge to 80% because there were zero stalls left 24/24 had been taken when i pulled in. Is the rate of charge reduced when all stalls are taken? even with Gen 3? Also, it took significantly longer to charger because on average it was giving me 180 miles/hour.. vs 440 on my way down. Does the supercharging bill only account for how much energy is consumed into the car vs the time? because this charging trip took twice as long...

Yes, version 3 Superchargers will still throttle when the site is full depending on the size of the utility transformer, whether or not the station has battery storage and/or solar, and the total vehicle load. A full 24 stall V3 with no solar and no battery storage would be limited to about 87.5 kW per vehicle assuming the utility transformer was sized at 2,000 kVA or greater.

Lastly, on the trip back i was less worried about conserving energy and more focused on getting home from the long weekend. My speed stayed around 80+ even through some pretty high hills (Santa Barbara). As expected my WH/MI was significantly higher than my trip down.

Drag is proportional to velocity squared. If a vehicle's speed doubles, air drag quadruples.

Here's a good energy consumption chart for Model S (source: Tesla Range Plotted Relative To Speed & Temperature (Graphs))

When plugging into my charger and setting the limit to 100 i noticed i lost about 3 miles of range from 100% as before? does Tesla use their 100% range indication based on recent driving style? or is this me losing battery range with a new vehicle? BTW i do not charge to 100 i was just interested in seeing if it had changed.

-Kaz

Range displayed on the battery meter is not dynamic based on recent driving style. It is calculated using a fixed constant based on EPA rated energy consumption and is unrealistic in all but ideal driving conditions and speed. As this number decreases, it indicates your battery losing capacity. Note that some initial capacity loss is totally normal for lithium ion cells, but it will level off after the initial decrease.

My 2018 Model 3 started at 303 miles (never did get the 310 advertised) and dropped to about 285 miles over the first 30,000 miles. It continues to hover around in the 280 - 290 range with 110,000 miles on the vehicle. Note that battery state of charge is a calculation that has a bit of drift in its accuracy depending on a number of factors including your charging behavior, so don't let a little variation keep you up at night.

Finally, changing the display from miles of range to percent remaining will do a lot to take your mind off of your battery health. Car menu > Display > Distance/Percent. I leave my car on % and will occasionally toggle back to distance just to check on the current state of health... I find % to be less paranoia inducing.

Congrats on your new Tesla!

 

[Big Earl]

I never knew what these 2 fields meant until this past supercharger session, which I commented above.

Once you're done with the session, the BMS will actively try and cool the pack down to 86F.

The way I read it, the BMS will passively cool the pack down to 86F (no compressor). Active cooling would stop once it's below 131F in the example shown.

 

[Rocky_H]

I don't know how I missed this earlier, where the explanation of sharing was wrong.

You hould be able to tell by looking at the bottom on the charger and if you see a marking that says a1 or c2 that’s how you know that you are sharing a stall. (A1 and A2 share the same 150kw for example).

The concept is right, but you got the naming incorrect. Each number corresponds to one of the charging cabinets, but it is A and B that share that power. You said A1 and A2 share. That's not right--those would be going to cabinet 1 and cabinet 2. 1A and 1B would be sharing.