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How I Recovered Half of my Battery's Lost Capacity

vickh

Active Member
Dec 16, 2018
3,118
488
az
@Candleflame, your reply had a lot of good information, but this part is not correct. With the exception of the 10% top locked SR and recent shenanigans with the new packs in EU cars, Model 3 batteries charge up to 4.2V per cell. This has been widely seen and reported.

Here’s an example at 100% SOC showing 403V at the pack and 4.20V at the cell level. Start at about 2:40.

Any special instructions for the 10% top locked SR?
 

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vickh

Active Member
Dec 16, 2018
3,118
488
az
Never fret about charging to 100%. But I don’t know any BMS calibration tricks for SR cars.

Yes I've been ignoring the car warnings. But I don't charge to 100% usually, only when I travel and that's not often these days..

Low SOC (20-50%) usually is probably affecting my BMS. I'll follow OP's directions soon.
 

Swordtail

Member
Oct 23, 2020
23
7
UK
Apologies if this is covered somewhere in the 22 pages of comments :confused: but given all the talk of battery calibration, how accurate is the percentage battery remaining and the wh/mile figures given in the trip counters?

I've got a 2021 Model 3 which has a 82 kWh battery. As such, I'd assume 1% on the battery indicator would equate to 820 Wh.

If the trip tells me I drove 20 miles @ 410 Wh/mile, can I be confident that would equate to 2 miles per 1% of battery and therefore I'd have a range of 200 miles? I believe the trip includes all power usage (battery heater/AC/fans/seat heaters etc) while the car is in "Drive" and so wouldn't include any drain while parked up, such as sentry mode.

I'd done a few comparisons of the trip quoted Wh/mile figures against the percentage drain (taking into account possible partial percentages) which didn't always quite tally up.

Sorry, I know this is looking at quite a lot of detail and "just enjoy the car" and all that, but as this is the first electric car I've owned, I just like to understand how much the reported information can be replied upon.

Cheers.
 

Candleflame

Active Member
Mar 9, 2015
2,921
1,362
QLD, Australia
Apologies if this is covered somewhere in the 22 pages of comments :confused: but given all the talk of battery calibration, how accurate is the percentage battery remaining and the wh/mile figures given in the trip counters?

I've got a 2021 Model 3 which has a 82 kWh battery. As such, I'd assume 1% on the battery indicator would equate to 820 Wh.

If the trip tells me I drove 20 miles @ 410 Wh/mile, can I be confident that would equate to 2 miles per 1% of battery and therefore I'd have a range of 200 miles? I believe the trip includes all power usage (battery heater/AC/fans/seat heaters etc) while the car is in "Drive" and so wouldn't include any drain while parked up, such as sentry mode.

I'd done a few comparisons of the trip quoted Wh/mile figures against the percentage drain (taking into account possible partial percentages) which didn't always quite tally up.

Sorry, I know this is looking at quite a lot of detail and "just enjoy the car" and all that, but as this is the first electric car I've owned, I just like to understand how much the reported information can be replied upon.

Cheers.


no because there are buffers. but yeah if you drive 410wh/mile your consumption is ultrahigh.
as a rukle of thumb, you get rated range by driving 95-100kmh with aircon off.

Not sure what your rated km are - for the previous generation 3s it was around 150w/km for the AWD and i think... 142w/km for the SR.
 

Swordtail

Member
Oct 23, 2020
23
7
UK
no because there are buffers. but yeah if you drive 410wh/mile your consumption is ultrahigh.
as a rukle of thumb, you get rated range by driving 95-100kmh with aircon off.

Not sure what your rated km are - for the previous generation 3s it was around 150w/km for the AWD and i think... 142w/km for the SR.

I'm not sure about Wh/km. In the UK the long range AWD has a WLTP range of 360 miles. On an 82 kWh battery that would mean 228 Wh/mile.

I only used 410 wh/mile to make the math easier for my example as 1% should be 820 Wh on a 82 kWh battery, and so you'd expect to get 2 miles per 1% reported battery usage at that consumption and a range of 200 miles.

My question is, let's say I'm driving quickly with AC on and the battery heater is on because I didn't precondition. If the trip computer reports a consumption of 410 Wh/mile, can I trust that the car really did consume an average of that amount of electricity over the trip? And can I trust that 1% on the battery meter really does equate to 820 Wh?

I've reconciled the % battery loss against the number of miles and Wh/mile figure given by the trip computer and it doesn't always tally up, even taking into account that partial percentages may have been used.

I expect the answer is that 1% of battery as reported by the car isn't necessarily always going to be exactly 820 Wh (or whatever 1% is if the battery has degraded). Perhaps at one point in time 1% used is actually 900 Wh and at another point in time 1% used is 800 Wh as the BMS is just estimating?

And perhaps the trip computer is accurately displaying the Wh/mile as it's easy enough to measure the actual energy drawn from the battery?

Cheers.
 

AAKEE

Member
Jan 8, 2021
269
268
Sweden
If you have a 2021 Long range, then You most probably have the smaller Panasonic( marked 77.8kwh) or the LG( marked 74.5kwh).
As far as we know it is only the Performance that gets the 82 kwh battery.

For your calculations you need to subtract the brick protection( buffer), 3.5 kwh on the 77.8kwh battery, that leaves you with 74.3kwh to use if the battery actually can store 77.8kwh which isnt always the case.

1% on the 77.8-batt therefore would be around 743Wh I think.

Further, the only place where WLTP counts is in the broschure. The range counter wont use WLTP but more or less the US EPA. ( which I think is calculated on the whole battery size without the buffer.

So you have around 74.3 kwh to use.
 
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Candleflame

Active Member
Mar 9, 2015
2,921
1,362
QLD, Australia
I'm not sure about Wh/km. In the UK the long range AWD has a WLTP range of 360 miles. On an 82 kWh battery that would mean 228 Wh/mile.

WLTP grossly overstates range. EPA is closer to reality and almost the same as Tesla rated km/mile. I think if you have the new panasonic batteries you have like 320 rated miles. Check in your tesla what your rated range is at 100% or you can extrapolate from lower SOC. If you have an 82kwh battery then probably 1-2kwh is reserved for brick protection and 4.5% is reserved as sub 0% buffer so you only have 76.4kwh available. So thats around 240wh/rated mile (fits with 150w/km which Tesla seems to use for the AWD 3s)

I only used 410 wh/mile to make the math easier for my example as 1% should be 820 Wh on a 82 kWh battery, and so you'd expect to get 2 miles per 1% reported battery usage at that consumption and a range of 200 miles.

if you run your heater to the max and floor the car all the time range will suffer. 410 is very high.

My question is, let's say I'm driving quickly with AC on and the battery heater is on because I didn't precondition. If the trip computer reports a consumption of 410 Wh/mile, can I trust that the car really did consume an average of that amount of electricity over the trip? And can I trust that 1% on the battery meter really does equate to 820 Wh?

No, the car trip computer is actually very off but this shouldnt be a concern for the normal user i.e. its accurate enough for your purposes. While you are in D (drive) the car uses all consumed power and divides it by distance driven (minus battery waste heat which is <1kwh)

I've reconciled the % battery loss against the number of miles and Wh/mile figure given by the trip computer and it doesn't always tally up, even taking into account that partial percentages may have been used.

might be because its not completely accurate. Also once you have degradation the car uses a formula to change % closer to initial % (i.e. 90 -100% is 45km with 10% degradation but 10 - 0% is 50km) But your math is flawed anyway. If you want to calculate how much you use use rated miles, not %.

I expect the answer is that 1% of battery as reported by the car isn't necessarily always going to be exactly 820 Wh (or whatever 1% is if the battery has degraded). Perhaps at one point in time 1% used is actually 900 Wh and at another point in time 1% used is 800 Wh as the BMS is just estimating?

The answer is to not use % when you calculate consumption as that doesnt mean anything. Use rated miles.

And perhaps the trip computer is accurately displaying the Wh/mile as it's easy enough to measure the actual energy drawn from the battery?

The answer is to not use % when you calculate consumption as that doesnt mean anything. Use rated miles.

Cheers.
 

Candleflame

Active Member
Mar 9, 2015
2,921
1,362
QLD, Australia
If you have a 2021 Long range, then You most probably have the smaller Panasonic( marked 77.8kwh) or the LG( marked 74.5kwh).
As far as we know it is only the Performance that gets the 82 kwh battery.

For your calculations you need to subtract the brick protection( buffer), 3.5 kwh on the 77.8kwh battery, that leaves you with 74.3kwh to use if the battery actually can store 77.8kwh which isnt always the case.

1% on the 77.8-batt therefore would be around 743Wh I think.

Further, the only place where WLTP counts is in the broschure. The range counter wont use WLTP but more or less the US EPA. ( which I think is calculated on the whole battery size without the buffer.

So you have around 74.3 kwh to use.

how is the LG battery so tiny? that surely must affect range? Oo. Thats like 15% less range than with the 82kwh battery.
 

AAKEE

Member
Jan 8, 2021
269
268
Sweden
how is the LG battery so tiny? that surely must affect range? Oo. Thats like 15% less range than with the 82kwh battery.

From what we know, the Long Range in EU have either the old panasonic sized battery or the LG, that is smaller.
I have seen discussions here about the panasonic being capped to make the range more like between the batteries.
I have a 21 Performance with the 82kwh batt so I havent dug deep inte the LR batteries.

You might wanna read this thread:
MASTER THREAD: 2021 Model 3 - Charge data, battery discussion etc
 

Candleflame

Active Member
Mar 9, 2015
2,921
1,362
QLD, Australia
From what we know, the Long Range in EU have either the old panasonic sized battery or the LG, that is smaller.
I have seen discussions here about the panasonic being capped to make the range more like between the batteries.
I have a 21 Performance with the 82kwh batt so I havent dug deep inte the LR batteries.

You might wanna read this thread:
MASTER THREAD: 2021 Model 3 - Charge data, battery discussion etc

still horribly unfair. A capped battery will mean you supercharger much quicker and experience less range degradation as you shallow cycle all the time.
 

MikeS

New Member
Oct 21, 2020
4
0
New Market, MD
Thanks to all for a great initial post and thread. Does Stats for Tesla prevent the vehicle from sleeping while parked at night and thereby prevent the OCV readings to which the original post referred? If it does, is there a setting in the app that can remove the interference? I'm thinking about buying the app but don't want to create range indication problems for myself.
 

Swordtail

Member
Oct 23, 2020
23
7
UK
The answer is to not use % when you calculate consumption as that doesnt mean anything. Use rated miles.

When you say to use the rated range, do you mean set the battery meter to show miles and work out the actual miles achieved per mile the meter reduces by?

Also, I'm pretty sure the UK 2021 Model 3 has the 82 kWh battery from everything I read. The WLTP range did go from 348 miles on the old model to 360 miles on the 2021. I understood this was due to the battery increase from 79 kWh to 82 kWh and the heat pump.
 

KenC

Active Member
Sep 4, 2018
3,602
3,271
Maine
Thanks to all for a great initial post and thread. Does Stats for Tesla prevent the vehicle from sleeping while parked at night and thereby prevent the OCV readings to which the original post referred? If it does, is there a setting in the app that can remove the interference? I'm thinking about buying the app but don't want to create range indication problems for myself.
It's not supposed to prevent the car from sleeping, but some users have posted complaints about it. Is there a setting? No. Depending upon what you are interested in, there are other apps, that may meet your needs
 

AAKEE

Member
Jan 8, 2021
269
268
Sweden
, I'm pretty sure the UK 2021 Model 3 has the 82 kWh battery from everything I read. The WLTP range did go from 348 miles on the old model to 360 miles on the 2021. I understood this was due to the battery increase from 79 kWh to 82 kWh and the heat pump.

There has been many posts and rumours about this. Worst was the German TÜV that put 77, 79 or 82 kwh info more or less randomly. A lot of people was unhappy because ”they didnt get the 82kwh batt”.

When all things sorted out, it was found that not a single LR that actually has been checked with scan my tesla or similar really had the 82kwh. All LR seem to have either the Pana 77.8 or the LG 74.5 kwh

The outside air temp for WLTP (+15 or similar) makes the need for heating or AC = zero. Hest pump gain will be seen IRL but dont show on the WLTP.
If you do the calculation with the 82kwh batt on the LR, its 5.6% more energy to use, which would cause the WLTP to rise to 592km ( from 560) from the battery only. There has been other changes, like tyres with lower rolling drag etc, so most people expect > 600 km when/if the 82 kwh goes into the LR. ( you can do the km to mile caöc self, I guess)

The model 3 performance did get more range extension than the increased batt size, about 1.3% extra range.
 
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AAKEE

Member
Jan 8, 2021
269
268
Sweden
So is there a simple (or complicated?) way for us 2021 LR owners to know if our cars have an LG or Panasonic battery? I'd like to know out of curiosity :).

-Get Scan My Tesla( not that cheap). I didnt get it for the battery size but of technical interrest.

-Or check via the Energy app in the car.
Its beat to have a decent charge, perhsps at least 70%. There are others that know this better than me, use the enegy app to see the average cunsumption for 50km( maybe 30miles with miles selected), and look for the range to the right on the same page( do not use momentary range, but the other one, dont remember what its called.)
Then divide that number with the battery % divided by 100( 73% = 0.73)

I have 152wh/km times (use 0.152) range 270km divided by 0.51 gives the value 80.47kwh.
Scan my tesla reported [nominal full pack] 80.6 kwh that same day.
Nominal full pack is the actual kwh that the battery can store according to the BMS.
This way of doing it seems to work ok.
9-ADC9-EE3-348-F-4-F62-B9-AB-1-A3-B3-B41-BF62.jpg

27-BBEE62-2-BBE-41-E9-9-AC2-BC8674-BD8-ACE.png
 

AAKEE

Member
Jan 8, 2021
269
268
Sweden
So I expect you will come up to somewhere in the ballpark about 77, if it is the E3D pack(panasonic) , and 74 if it is the E5D (LG).


I did forget the most simple thing: The Panasonic battery give the car the E3D mark and the LG E5D. This might be found in your cars registration paper.

Fot the question about 77.8 or the new 82.1kwh batteri, both is E3D and made by Panasonic so the size will not be found that easy. But as far as we know, all LR with E3D have the old sized 77.8kwh battery.

Heres the thread about 2021 batteries:
MASTER THREAD: 2021 Model 3 - Charge data, battery discussion etc
 
Last edited:

Candleflame

Active Member
Mar 9, 2015
2,921
1,362
QLD, Australia
When you say to use the rated range, do you mean set the battery meter to show miles and work out the actual miles achieved per mile the meter reduces by?

Also, I'm pretty sure the UK 2021 Model 3 has the 82 kWh battery from everything I read. The WLTP range did go from 348 miles on the old model to 360 miles on the 2021. I understood this was due to the battery increase from 79 kWh to 82 kWh and the heat pump.

yes. rated miles is a unit of energy (its directly linked to a constant of watthourage). % is not.

This becomes really important when you have degradation as the closer you get to 0% the closer the car appears to have no degradation. Or in other words, range per % increases the lower your state of charge is - if you have degradation.
 

KalJoMoS

Member
Aug 11, 2019
340
192
EETN, EST
Isn’t there on Model3 and ModelY a label on the battery as it is on S and X, stating your battery size and voltage? On S/X it’s behind front RH wheel liner easily seen if steering is turned to the left full lock.
 

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