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MASTER THREAD: Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health

May 28, 2021
40
19
Florida
2021 or 2020 Model 3 SR+ owners- how many miles you drive per percentage of usage displayed on dash? Are you able to typically achieve less than 225 wh/miles? I understand the percentage left displayed on the dash is estimation but I am curious as I am wondering my driving habits are good or not. I typically run climate on 75 and have music playing all the time. The mileage per percentage is about 2.1-2.2. Is that typical or am I using up more battery juice for less mileage? I have 2021 Model 3 SR+.
 

badd_r

New Member
Jul 27, 2021
2
2
dubai
Hi!
I live in Dubai (Highs of 45 degrees Celsius(113F) in summer, low of 15 degrees Celsius (59F) in winter), i have a model 3 Performance 2020 with just under 20K kms (12K miles) and owned the car for almost 1 year.

I've noticed that my original range of 450 KM (280 miles) when I charge it up to the recommended line (90%) is now down to 400 KM. So I gave tesla a call they recommended I go for a long 100KM (60 miles) or more drive to fix the estimates.. so I did this.. no changes...

took it into the service center and they did the diagnostics and told me i've lost 9% of the batteries capacity and that this is normal in the first year and that for the first one to one year and a half we will have this drop of range then it will stop dropping... He also mentioned that they wouldn't change the batteries unless the capacity dropped below 75% of capacity.

Was wondering if anyone is experiencing anything similar

Thanks!
 
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rrolsbe

Member
Feb 18, 2017
237
131
Albuquerque
Some of the following may not be entirely correct so clarification from other forum members welcome. The traction battery gets wear and tear from both odometer miles as well as what I call battery miles. Traction battery miles includes all energy in and out of the battery all of which adds to reduce battery capacity over time. Given ambient air temps of 113F the battery cells are probably being activity cooled using power from the traction battery (when not plugged into shore power). When the traction battery cell temps reach 122F, the BMS must activity cool the cells. If the car is plugged into a shore power source that can supply enough power for this cooling function, there should not be any added battery wear. My 2018 M3 long range traction battery has lost around 7 to 8% (as per Scan My Tesla) but has never had the battery cells exposed to temps anywhere near -22F or above 122F. My M3 had 310 miles of range new and now has around 304 to 305 when fully charged. Tesla unlocked some of the upper battery capacity around a year after purchase.
 

Gasaraki

Active Member
Oct 21, 2019
1,993
1,246
Syracuse, NY
Hi!
I live in Dubai (Highs of 45 degrees Celsius(113F) in summer, low of 15 degrees Celsius (59F) in winter), i have a model 3 Performance 2020 with just under 20K kms (12K miles) and owned the car for almost 1 year.

I've noticed that my original range of 450 KM (280 miles) when I charge it up to the recommended line (90%) is now down to 400 KM. So I gave tesla a call they recommended I go for a long 100KM (60 miles) or more drive to fix the estimates.. so I did this.. no changes...

took it into the service center and they did the diagnostics and told me i've lost 9% of the batteries capacity and that this is normal in the first year and that for the first one to one year and a half we will have this drop of range then it will stop dropping... He also mentioned that they wouldn't change the batteries unless the capacity dropped below 75% of capacity.

Was wondering if anyone is experiencing anything similar

Thanks!
I would try to re-balance the BMS by driving to under 10% and going to a Supercharger and charging it to 100% until it stops and says 'Charging Complete'. It might take about 1.5 hours to do this though. Or you can do this at home if you can charge at home. Don't just stop when it get to 100%, let it naturally stop.

You'll notice that the car will charge to 100% but still be charging because the BMS is not really knowing the exact charge level of the battery. It will probably stay at 100% but continue to charge (really slow) for about half an hour.

You might have to do this a few times but don't need to do this too often. A few times a year maybe?
 

twlatl

New Member
Jul 27, 2021
3
1
Grayson, GA
I have a Model 3 Long Range 2021 model I took possession of in late Dec 2020. I keep it in a garage every night and charge it using a Tesla Wall Charger and typically get about 50 miles/hr charge. I’ve taken a a couple of long distance (about 500 miles each way) trips in the 8 months I’ve owned it, and have supercharged last than 10 times.

I generally charge to 80 or 90 percent each night and only charge to 100 percent when taking a long trip.

My dilemma is my full range is now reporting at 322 miles. That’s 34 miles and damn near 10 percent in only 8 months. Is this typical? I expectEd battery degradation but not that much that quickly, especially since Ive been following the best practices in charging behavior.
 
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AlanSubie4Life

Efficiency Obsessed Member
Oct 22, 2018
10,370
12,608
San Diego
My dilemma is my full range is now reporting at 322 miles. That’s 34 miles and damn near 10 percent in only 8 months.
Yes this is normal. It is possible the estimate is off a little and the actual rated range is something as high as ~330 rated miles, but generally speaking capacity loss like this is normal. You have a BMS-estimated 71kWh. How many miles on the odometer?

It will likely be quite slow from here. Maybe you’ll lose another 5% over the next year or two. It if you’re lucky, it might just be another couple %. (And as mentioned you might see a little recovery, then followed by a little loss.)

You can always drain the battery and let it sleep at various levels as mentioned elsewhere, to see some recovery. But probably not reasonable to expect more than 10 miles variation.

Unless you need it for convenience, you might charge to 70% each night. But the 80/90% charging is likely not the reason for the capacity loss.
 

rrolsbe

Member
Feb 18, 2017
237
131
Albuquerque
How do we know if that's true? How does the AC operate straight of AC current?

@rrolsbe
The AC is converted to DC to charge the traction battery and also supply DC to power components connected to the high voltage bus. I have verified the heater users shore power (which also uses the high voltage DC) but can't say for sure the AC does as well. Anyone know for sure?
 
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Candleflame

Active Member
Mar 9, 2015
3,138
1,462
QLD, Australia
Hi!
I live in Dubai (Highs of 45 degrees Celsius(113F) in summer, low of 15 degrees Celsius (59F) in winter), i have a model 3 Performance 2020 with just under 20K kms (12K miles) and owned the car for almost 1 year.

I've noticed that my original range of 450 KM (280 miles) when I charge it up to the recommended line (90%) is now down to 400 KM. So I gave tesla a call they recommended I go for a long 100KM (60 miles) or more drive to fix the estimates.. so I did this.. no changes...

took it into the service center and they did the diagnostics and told me i've lost 9% of the batteries capacity and that this is normal in the first year and that for the first one to one year and a half we will have this drop of range then it will stop dropping... He also mentioned that they wouldn't change the batteries unless the capacity dropped below 75% of capacity.

Was wondering if anyone is experiencing anything similar

Thanks!
9% loss a bit over a year is normal.

Where I live its tropical 35C in summer and 18C bottom in winter but the car also spent some time in climate similar to Dubai and I lost 7% in the first year and now my second year is coming to an end and I lost another 2%.
One reason you may have lost a bit more is maybe luck or because you leave the car at 90% in the dubai heat wheras my car spends a lot of time sitting at 50-70%. The role of heat and SOC is still not completely clear.

Tesla unfortunately lied about the degradation of the 3 when everyone expected Model S numbers.
I mean, I already got the long range model 3 but I am sure there are many people who would have rather bought a long range 3 if they would have known that they get 10% degradation after 1 year....
 

rmunson1

Member
Jul 28, 2021
11
1
Danville, CA
Calling me a 'newbie' is way too kind - I take delivery of my first Tesla (2021 SR+) in 6-8 weeks. I have spent many hours reading, and would spend years (lifetimes?) reading if I tried to read everything. I live in Danville, CA. If my questions were already addressed, I apologize. That said...

I expect to have close to 100% home charging (no current need for on-road charging, my wife's car will be used for road trips). Currently I plan to just use L1 charging, since I'm retired, don't drive that many miles/day and in no hurry/need to get a fill-up ready to drive tomorrow. I'm thinking for most uses/most days, I will charge to 60-70% and recharge when down to 30-40%. In this context:
  1. I've read L1 charging is less efficient than L2 (L2 vs. L1 efficiency) - but this is old (2014). Are there current numbers available and am I being foolish to use L1 charging due to charging efficiency issues? Perhaps this can only be answered by 'how many kWh will I burn over the life of the car?' in order to determine if the cost of a L2 installation is greater than the cost of the L1 wastage/inefficiency?
  2. From what I've read, keeping max SoC low and keeping DoD not low preserves battery life - any idea how much?
  3. Time of day to charge - daytime has my solar running and I can use that electricity as it is produced, but daytime has higher temperatures (currently often in the 90s in the garage). Does the daytime heat make charging less efficient? Or is the heat hard on the battery (or both)? Obviously another consideration is cents/kWh - I'm currently around 16 cents. PG&E offers lower rates at night at the expense of higher rates during the day - I have currently not opted in to that program due to very high cost of daytime usage.
  4. Battery life seems to be defined in terms of 'how many 100%-0% discharge/recharge cycles can be performed until the battery has degraded to the point of not being usable?' If I literally do 60-40 (real world could never be that consistent), does doing that (60-40) recharge cycle 5 times count as '1 cycle' in terms of 100-0 style of charging? Or would doing 60-40 cycles 5 times actually be much less (or more) than one 100-0 recharge?
Thanks for bearing with me as I wait for my new Tesla and plan how to charge/use it.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
10,256
11,596
Riverside Co. CA
Calling me a 'newbie' is way too kind - I take delivery of my first Tesla (2021 SR+) in 6-8 weeks. I have spent many hours reading, and would spend years (lifetimes?) reading if I tried to read everything. I live in Danville, CA. If my questions were already addressed, I apologize. That said...

I expect to have close to 100% home charging (no current need for on-road charging, my wife's car will be used for road trips). Currently I plan to just use L1 charging, since I'm retired, don't drive that many miles/day and in no hurry/need to get a fill-up ready to drive tomorrow. I'm thinking for most uses/most days, I will charge to 60-70% and recharge when down to 30-40%. In this context:
  1. I've read L1 charging is less efficient than L2 (L2 vs. L1 efficiency) - but this is old (2014). Are there current numbers available and am I being foolish to use L1 charging due to charging efficiency issues? Perhaps this can only be answered by 'how many kWh will I burn over the life of the car?' in order to determine if the cost of a L2 installation is greater than the cost of the L1 wastage/inefficiency?
  2. From what I've read, keeping max SoC low and keeping DoD not low preserves battery life - any idea how much?
  3. Time of day to charge - daytime has my solar running and I can use that electricity as it is produced, but daytime has higher temperatures (currently often in the 90s in the garage). Does the daytime heat make charging less efficient? Or is the heat hard on the battery (or both)? Obviously another consideration is cents/kWh - I'm currently around 16 cents. PG&E offers lower rates at night at the expense of higher rates during the day - I have currently not opted in to that program due to very high cost of daytime usage.
  4. Battery life seems to be defined in terms of 'how many 100%-0% discharge/recharge cycles can be performed until the battery has degraded to the point of not being usable?' If I literally do 60-40 (real world could never be that consistent), does doing that (60-40) recharge cycle 5 times count as '1 cycle' in terms of 100-0 style of charging? Or would doing 60-40 cycles 5 times actually be much less (or more) than one 100-0 recharge?
Thanks for bearing with me as I wait for my new Tesla and plan how to charge/use it.

Welcome to TMC. I feel you are greatly (greatly) overthinking this, like a lot of new tesla owners (or soon to be new tesla owners).

1. People L1 charge all the time. The efficiency issue is because of the fact that the overhead of keeping the car awake is a larger percentage of the available power than at faster / higher amp charging. more energy is "wasted" because the car is awake taking a portion of the available power. However, if thats what you want to do, you will not hurt the car by doing it.

2. No one knows, although the thread I moved your post to shows that some people really enjoy talking about this subject.

3. Charge overnight unless you have some pressing need not to. You generate NEM credits during the day, and likely have had your solar for a few years now if you are not on a TOU plan (those became mandatory with solar installs in CA in the past few years).

4. A battery cycle is counted as 1 "drain the battery to zero, and fill it back up" cycle. If you charge 20% of the battery 5 times that counts as one cycle.

My opinion is, you have already sent yourself down the "battery rabbit hole". None of this is necessary to think about unless you actually enjoy pondering all this stuff. I am going to link something I just recently said in the model Y subforum to someone with questions below. This is my opinion on it. I am just one person, and my opinion does NOT count for anything special because I happen to be a volunteer moderator here, its just how I feel.

Most of the stuff on TMC highly (highly highly) overcomplicates charging.

All you need to do is get an outlet put close to where you park, if possible, and plug in when you get home. Set the car at somewhere between any of the lines that show in the tesla app as "daily usage" (from 50% to 90%), and thats it. Literally thats it. No need to set it to 83.3364926230474% on tuesdays but only if the sun is out.

No need to keep charts the last time you plugged in, or wonder if its ok to plug in every day or not (either is fine). No need to stress about "if you are doing it right" (although a lot of people here enjoy the %[email protected]$ out of stressing about this stuff).

Just ask an electrician "what is the fastest 240v plug I can put in my panel without upgrades, for charging an EV, up to 60amp?", have them put it in, and plug in when you get home.
 

AlanSubie4Life

Efficiency Obsessed Member
Oct 22, 2018
10,370
12,608
San Diego
Perhaps this can only be answered by 'how many kWh will I burn over the life of the car?' in order to determine if the cost of a L2 installation is greater than the cost of the L1 wastage/inefficiency?

For Teslas: assume about 78% charging efficiency with 120V 12A vs. 88% charging efficiency with a max amperage (240V 32A for SR+) L2 installation. Can calculate roughly from that.

At 20 cents per kWh, assuming 10k miles per year of driving, with 230Wh/mi average driving efficiency, and general "feature usage" (Sentry, vampire, sitting stationary in Park, etc.) overhead of an additional 230kWh per year:

$0.2/kWh* (1/0.78-1/0.88)*(10kmi/yr*230Wh/mi + 230kWh/yr) = $74 per year.

You can adjust your parameters accordingly - with TOU and other factors like whether extra usage means more AC usage priced at peak rates for you, the additional kWh cost gets pretty complicated to price out. You know your situation best.

L1 charging will likely work great for someone in your situation.
 
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snikt

Member
May 14, 2021
250
359
Denver, CO
I generally get between 88-92% efficiency charging on my L2 at home, though I've seen a couple times at 94%.

It seems like the longer charging sessions I get 90-94 and the shorter sessions after only driving to work and back I get 88-90
 

AlanSubie4Life

Efficiency Obsessed Member
Oct 22, 2018
10,370
12,608
San Diego
generally get between 88-92% efficiency charging on my L2 at home, though I've seen a couple times at 94%.

You need to be careful how you measure this - you cannot use the kWh added displayed on the screen in the car (because that does not reflect energy added to the battery - it's a simple multiplication of the charging constant and the rated miles added), and divide by the wall energy.

You would need to use SMT or similar CAN tool to measure energy added to the pack, and divide by the wall energy (assuming you have metering of your EVSE, etc.). Or use the known relationships of rated miles (derived observationally from SMT and other information) to energy, and divide by wall energy.
 

snikt

Member
May 14, 2021
250
359
Denver, CO
You need to be careful how you measure this - you cannot use the kWh added displayed on the screen in the car (because that does not reflect energy added to the battery), and divide by the wall energy.

You would need to use SMT or similar CAN tool to measure energy added to the pack, and divide by the wall energy (assuming you have metering of your EVSE, etc.). Or use the known relationships of rated miles (derived observationally from SMT and other information) to energy.

I'm using data from TeslaMate, would this not be as accurate since this would be to be all data coming from the car itself?

1627679018339.png
 

AlanSubie4Life

Efficiency Obsessed Member
Oct 22, 2018
10,370
12,608
San Diego
I'm using data from TeslaMate, would this not be as accurate since this would be to be all data coming from the car itself?

View attachment 690058

You'd have to read in the docs about how the "used" energy is calculated, and how the "added" was calculated.

Since it appears to have access only to the API, for the added energy, the app would need to know the scaling of 0.955 to apply to the "kWh added" value. It all depends on how the code is written.

In order to calculate efficiency, TeslaMate would also need information from the wall (I assume it looks at voltage and current over time during a charging session, which would be fine, integral of V*A over time is energy from the wall (at the vehicle plug and neglects other wiring losses)).

Anyway, it should take the kWh added from the API, multiply it by 0.955, and divide by the wall energy from the integral, and that would be approximately correct. That's just the way it works (can verify with SMT).

"kWh added" is potentially different than "kWh used" - but it depends on their definitions. (Clearly is in this case. There's kWh used from the wall, and kWh used from the battery, two totally different quantities.)

Nothing wrong with Teslamate, as far as I can tell - looks like a good open-source tool. But the API values for kWh added do not match the energy added to the battery. (Again, the added energy is just rated miles added multiplied by the vehicle charging constant.)

Max possible efficiency is around 88-89%, per the EPA docs (which uses max charge rate for the vehicle based on recent info that came to light in some of the documents). And this will align with observations too.

Your max values coming in at 93% or so (apparently) are consistent with this, too. Make the 4.5% adjustment, making those 88.5%, and then everything lines up.
 
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twlatl

New Member
Jul 27, 2021
3
1
Grayson, GA
Yes this is normal. It is possible the estimate is off a little and the actual rated range is something as high as ~330 rated miles, but generally speaking capacity loss like this is normal. You have a BMS-estimated 71kWh. How many miles on the odometer?

It will likely be quite slow from here. Maybe you’ll lose another 5% over the next year or two. It if you’re lucky, it might just be another couple %. (And as mentioned you might see a little recovery, then followed by a little loss.)

You can always drain the battery and let it sleep at various levels as mentioned elsewhere, to see some recovery. But probably not reasonable to expect more than 10 miles variation.

Unless you need it for convenience, you might charge to 70% each night. But the 80/90% charging is likely not the reason for the capacity loss.
I have 8810 miles driven so far. That seems like a lot of degradation for so few miles and such a short time of ownership…
 

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