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How I Recovered Half of my Battery's Lost Capacity

Candleflame

Active Member
Mar 9, 2015
3,189
1,494
QLD, Australia
Very frustrated with my Tesla Model 3 LR (2018, delivered in 9/18). I have lost 14% of my battery capacity in under 3 years and 30,000. I'm a very careful charger, rare trips, rare supercharging, very, very rare 100% charges. Here is what I get from the service center:

View attachment 679242

I don't consider 14%'slight degradation' and really don't want to have to wait another 3 years to get to 70% and a new battery. Other than the charging maneuvers outlined above, any other thoughts? Thanks. Jon

Its the standard reply you get until its 30%. Unfortunately there is nothing you can do about it. Its frustrating. Best advice i can give is to trade your car in for a different one... Its the battery lottery. If its any condolences model 3 usually does degrade to 10% quite quickly. I suspect you have a faulty module the car has bypassed....
 

JonAHupp

New Member
Mar 6, 2020
2
0
Annapolis, MD
Its the standard reply you get until its 30%. Unfortunately there is nothing you can do about it. Its frustrating. Best advice i can give is to trade your car in for a different one... Its the battery lottery. If its any condolences model 3 usually does degrade to 10% quite quickly. I suspect you have a faulty module the car has bypassed....
Trading in the car is not desirable for the following reasons:

1) I like my car
2) I purchased FSD (if I live long enough to ever get it) when it was on-sale for $2,000.
3) I have lifetime premium connectivity.
4) No real guarantee that the new car and new battery pack will be better (other than the better initial range on newer Model 3's)

I'm sure the FSD and connectivity are not transferrable so I'll hold on to my car for a while.
 

jim0266

Member
Mar 20, 2019
78
128
Ohio
Quick G-Sheet to double check what SoC that would be.
7V1PkQN.jpg
Is there any proof of that though? I.e. someone who does have a bit of cell imbalance keeping their car below i.e. 90% and see if it still balances? Interestingly most if not all cars seem to be in good balance anyway ie. Less than 1% rangeloss suggesting that the car may have other ways to balance the pack than the bleeder circuits.... Or possibly a 100% charge is enough to instantly rebalance the pack.

Also i seem to recall that some owners who do refer to the 4v limit state that their car reads above 4v already in the high 70s%...
I happened to charge to 75% last week and captured this SMT image of the battery page. The car actually charged to 74.4%, showing:

Cell Volt Max 4.022
Cell Volt Min 4.102
Cell Volt Avg 4.017

This is from a LR RWD Model 3 with just over 12K miles that had the range boost to 325 miles.
 

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Candleflame

Active Member
Mar 9, 2015
3,189
1,494
QLD, Australia
Modules can't be bypassed... (In any of Tesla's battery packs.)

i thought if a module fails the car wont try to balance those cells anymore as they bleed voltage too quickly so you end up having a sagging low voltage in that pack which essentially doesnt contribute much to the overall voltage (which leads to higher amps needed to produce the power).
 

Candleflame

Active Member
Mar 9, 2015
3,189
1,494
QLD, Australia
I happened to charge to 75% last week and captured this SMT image of the battery page. The car actually charged to 74.4%, showing:

Cell Volt Max 4.022
Cell Volt Min 4.102
Cell Volt Avg 4.017

This is from a LR RWD Model 3 with just over 12K miles that had the range boost to 325 miles.
then clearly the table is off....
 
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MP3Mike

Well-Known Member
Feb 1, 2016
16,224
36,576
Oregon
i thought if a module fails the car wont try to balance those cells anymore as they bleed voltage too quickly so you end up having a sagging low voltage in that pack which essentially doesnt contribute much to the overall voltage (which leads to higher amps needed to produce the power).
That isn't a failure, that is just a weak module/brick. But it also has to shut the car down when the voltage of that brick/module reaches 0%. (It may be weak but it is still contributing to the usage.)

And the BMS only balances the bricks with the highest voltage. (Bleeding them down to match the rest.)
 

Candleflame

Active Member
Mar 9, 2015
3,189
1,494
QLD, Australia
im still not convinced that for balancing/bleeding a high SOC is needed. my car is actually sitting at like 50-75% (mainly around 60%) for the last 2 months. might have a look on SMT in a sec.
 

MP3Mike

Well-Known Member
Feb 1, 2016
16,224
36,576
Oregon
im still not convinced that for balancing/bleeding a high SOC is needed. my car is actually sitting at like 50-75% (mainly around 60%) for the last 2 months. might have a look on SMT in a sec.
I didn't say a high SOC was needed. I said only the highest voltage bricks are balanced/bleed.
 

Candleflame

Active Member
Mar 9, 2015
3,189
1,494
QLD, Australia
had a look earlier.

SOC 70%, cell volt max 3.968, cell volt mid 3.966, cell volt min 3.962. Imbalance 6 mV after letting the car run for 5min. at the beginning it was 4mV imbalance.
full rated range is at 455km atm.
 

DarkNightP3D

Member
Jan 10, 2020
141
179
Raleigh, NC, USA
I’m down to 246 miles at 90% on my P3D. Nothing I’ve tried including varying SOC, letting sit at low SOC for 12+ hours, then charging to 90%-95%, etc. has made any difference to my cars claimed range estimates. I’m at 41K miles. When new 90% showed 279 miles of range. Losing over 10% of my car’s range is a bit disappointing. ABRP says my car’s pack capacity is down to 68.1kWh. Anyone have any luck getting Tesla to do the “CAC reset” that I’ve read has magically recovered “missing” capacity?
 

Candleflame

Active Member
Mar 9, 2015
3,189
1,494
QLD, Australia
I’m down to 246 miles at 90% on my P3D. Nothing I’ve tried including varying SOC, letting sit at low SOC for 12+ hours, then charging to 90%-95%, etc. has made any difference to my cars claimed range estimates. I’m at 41K miles. When new 90% showed 279 miles of range. Losing over 10% of my car’s range is a bit disappointing. ABRP says my car’s pack capacity is down to 68.1kWh. Anyone have any luck getting Tesla to do the “CAC reset” that I’ve read has magically recovered “missing” capacity?

im on 69 kwh and im just very slightly below average on teslafi after 2 years and 40000 km. i think the model 3 has just heavy degradation in general which is disappointing but it is the way it is. Its kinda frustrating to see the i.e. Model S with 500k kms and 7 years to still only have i.e. 11% degradation.

Interestingly many of the initial RWD 2018 cars have very little degradation which is more akin to the S/X degradation.

I do think the governments need to come up with somme kind of standard to take degradation into account for range advertisement.
 
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Rmorse1

Member
Jul 20, 2021
6
1
Phoenix
Whoops.

Didn't mean to post the above.

Curious to hear what the community thinks of my situation. Bought a used 2019 SR+ from Tesla. 21k Miles. No FSD. Car has been in AZ.

I was surprised to see my max range at 203 on my first day when I charged up to 100%.

I've tried some of the tips in the post, but I decided to really focus on the capacity more than 100% SOC.

I've done a 100 to 0 % drive to see what my KW used would be and I was at 42KW with 2 miles left on my range.

Per my calculations based on another post here, I have between 42.5 & 43.5 KW usable. Down from 55KW * .95 (BUFFER)= 52.25 KW

I've reached out to tesla and to quote, they said my battery is in "excellent health". Current 100% state of charge has not gone above 200 in the last month. I've been averaging 196 to 198. I'm only 2K miles in since I bought at the beginning of June. Really wrestling with whether to trade it in or not in the current market. Obviously if my degradation is truly at -18% or so, I'm on track to hit 70% within the battery warranty. Per teslafi there is only one other car out of 450 at the same level as me. I'm the 1% on the low end of range.
 

Candleflame

Active Member
Mar 9, 2015
3,189
1,494
QLD, Australia
Whoops.

Didn't mean to post the above.

Curious to hear what the community thinks of my situation. Bought a used 2019 SR+ from Tesla. 21k Miles. No FSD. Car has been in AZ.

I was surprised to see my max range at 203 on my first day when I charged up to 100%.

I've tried some of the tips in the post, but I decided to really focus on the capacity more than 100% SOC.

I've done a 100 to 0 % drive to see what my KW used would be and I was at 42KW with 2 miles left on my range.

Per my calculations based on another post here, I have between 42.5 & 43.5 KW usable. Down from 55KW * .95 (BUFFER)= 52.25 KW

I've reached out to tesla and to quote, they said my battery is in "excellent health". Current 100% state of charge has not gone above 200 in the last month. I've been averaging 196 to 198. I'm only 2K miles in since I bought at the beginning of June. Really wrestling with whether to trade it in or not in the current market. Obviously if my degradation is truly at -18% or so, I'm on track to hit 70% within the battery warranty. Per teslafi there is only one other car out of 450 at the same level as me. I'm the 1% on the low end of range.

until you hit 70% tesla will tell you that you have an amazing battery.
 
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SucreTease

Teslarian
Jul 11, 2017
749
1,087
Madison, Alabama
Whoops.

Didn't mean to post the above.

Curious to hear what the community thinks of my situation. Bought a used 2019 SR+ from Tesla. 21k Miles. No FSD. Car has been in AZ.

I was surprised to see my max range at 203 on my first day when I charged up to 100%.

I've tried some of the tips in the post, but I decided to really focus on the capacity more than 100% SOC.

I've done a 100 to 0 % drive to see what my KW used would be and I was at 42KW with 2 miles left on my range.

Per my calculations based on another post here, I have between 42.5 & 43.5 KW usable. Down from 55KW * .95 (BUFFER)= 52.25 KW

I've reached out to tesla and to quote, they said my battery is in "excellent health". Current 100% state of charge has not gone above 200 in the last month. I've been averaging 196 to 198. I'm only 2K miles in since I bought at the beginning of June. Really wrestling with whether to trade it in or not in the current market. Obviously if my degradation is truly at -18% or so, I'm on track to hit 70% within the battery warranty. Per teslafi there is only one other car out of 450 at the same level as me. I'm the 1% on the low end of range.
All of your "kw" or "KW" units should have been "kWh". Energy quantities in electrical systems are measure in kWh (kilowatt-hours).
 

Dave EV

Active Member
Jun 23, 2009
1,864
1,450
San Diego
Whoops.

Didn't mean to post the above.

Curious to hear what the community thinks of my situation. Bought a used 2019 SR+ from Tesla. 21k Miles. No FSD. Car has been in AZ.

I was surprised to see my max range at 203 on my first day when I charged up to 100%.

I've tried some of the tips in the post, but I decided to really focus on the capacity more than 100% SOC.

I've done a 100 to 0 % drive to see what my KW used would be and I was at 42KW with 2 miles left on my range.

Per my calculations based on another post here, I have between 42.5 & 43.5 KW usable. Down from 55KW * .95 (BUFFER)= 52.25 KW

I've reached out to tesla and to quote, they said my battery is in "excellent health". Current 100% state of charge has not gone above 200 in the last month. I've been averaging 196 to 198. I'm only 2K miles in since I bought at the beginning of June. Really wrestling with whether to trade it in or not in the current market. Obviously if my degradation is truly at -18% or so, I'm on track to hit 70% within the battery warranty. Per teslafi there is only one other car out of 450 at the same level as me. I'm the 1% on the low end of range.
Get the ScanMyTesla App, an adapter cable and a bluetooth adapter - then you can get some more usable information on the pack, including balance at various states of charge.

Have you followed the instructions in this thread on how to encourage the BMS to recalibrate? The amount of capacity your car is reporting is high. That said - Arizona summer temperatures combined with high states of charge may not have been kind to the battery, though that seems extreme based on historical performance of Tesla batteries.

Note that there can be a substantial amount of buffer at the bottom of the pack...
 

AlanSubie4Life

Efficiency Obsessed Member
Oct 22, 2018
10,428
12,679
San Diego
Whoops.

Didn't mean to post the above.

Curious to hear what the community thinks of my situation. Bought a used 2019 SR+ from Tesla. 21k Miles. No FSD. Car has been in AZ.

I was surprised to see my max range at 203 on my first day when I charged up to 100%.

I've tried some of the tips in the post, but I decided to really focus on the capacity more than 100% SOC.

I've done a 100 to 0 % drive to see what my KW used would be and I was at 42KW with 2 miles left on my range.

Per my calculations based on another post here, I have between 42.5 & 43.5 KW usable. Down from 55KW * .95 (BUFFER)= 52.25 KW

I've reached out to tesla and to quote, they said my battery is in "excellent health". Current 100% state of charge has not gone above 200 in the last month. I've been averaging 196 to 198. I'm only 2K miles in since I bought at the beginning of June. Really wrestling with whether to trade it in or not in the current market. Obviously if my degradation is truly at -18% or so, I'm on track to hit 70% within the battery warranty. Per teslafi there is only one other car out of 450 at the same level as me. I'm the 1% on the low end of range.

This was posted and answered in the other thread, which it is probably more appropriate, though clearly related. To the topic of this thread, regarding how to recover this range - probably no way to do that. Though you can try the methods suggested in the first post, I wouldn't expect more than 1-2kWh recovery for most owners.

You are right to focus on the capacity, though (which is equivalent to the range at 100% SoC). It's the most important thing if you care about range or need to make a particular drive.

https://teslamotorsclub.com/tmc/posts/5730857/

though that seems extreme based on historical performance of Tesla batteries.
For a 2019 he's at a max of about 18% capacity loss, which is on the edge of the distribution, but not extreme (an outlier) I think. Original range was 240 and now he's at perhaps 198 (might be as high as 200 - it's hard to tell from the post whether the 198 number came from an actual true 100% charge or an extrapolated value).

Generally I'd expect higher capacity loss from an SR+, especially a used one (since once with high capacity loss would tend to get traded in). This is equivalent to an LR vehicle with 31k miles. So to me 18% isn't that surprising; it is just considerably worse than average.

There were a few reports of SR+ when new not quite reaching their 240 miles (52.5kWh) full pack value, too. So start at a lower initial capacity (who knows what cells Tesla was using to build those packs...maybe just the low capacity ones?) and it's possible it's only lost 13-15% (though that isn't helpful for an end user since the end result is quite low capacity and no one cares where it started).

Probably Tesla's cell quality control and process control is better (tighter) now but I could see them "binning" cells by capacity if they had process control issues initially. You'd need the bricks to be the same capacity for balance. I don't know at what level of assembly (cell or brick or module level) they would check the capacities during the manufacturing and assembly process.
 
Last edited:

spiceagent11

New Member
Jul 31, 2021
2
0
Bangalore
The BMS system is not only responsible for charging and monitoring of the battery, but computing the estimated range. The way it does this is to correlate the battery's terminal voltage (and the terminal voltage of each group of parallel cells) to the capacity. The BMS tries to constantly refine and calibrate that relationship between terminal voltage and capacity to display the remaining miles.
 

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