How I Recovered Half of my Battery's Lost Capacity

[N54TT]

I did progressively increase the SOC, and kept an eye on the cell imbalance. 60-70-80-90. There was no balancing until 90%. The imbalance stayed the same each time a few hours after reaching the SOC, except when reaching 90%, then the imbalance decreased quite quick to 2mV. (Was higher before).
Id say that is a clear indiocation that balancing doesnt occur below (about) 90%.

[Edit]Post about the balancing: MASTER THREAD: 2021 Model 3 - Charge data, battery discussion etc

how long did it take to balance?

 

[AAKEE]

how long did it take to balance?

Its in the link.

And just 3 1/2h with 90% the imbalance is down to 2mV.[/b]
I didnt check more than that.

My battery is quite well balanced. Most often 4mV imbalance and that time the imbalance was 4-6mV ( SMT Value jumped between 4-6) after reaching 90%.
If the Imbalance is high the time will be higher. As it is said to be resistors(?) with a fixed resistance, its likely that double imbalance takes double time as each mV corrensponds to a certain imbalance in capacity/ Whrs.

 

[Candleflame]

I did progressively increase the SOC, and kept an eye on the cell imbalance. 60-70-80-90. There was no balancing until 90%. The imbalance stayed the same each time a few hours after reaching the SOC, except when reaching 90%, then the imbalance decreased quite quick to 2mV. (Was higher before).
Id say that is a clear indiocation that balancing doesnt occur below (about) 90%.

[Edit]Post about the balancing: MASTER THREAD: 2021 Model 3 - Charge data, battery discussion etc

many people never go above 80% for months and have no imbalance. or like me, cycle 65% to 50% most of the time.

 

[Candleflame]

Btw, does degradation protect from acceleration limitation at low SOC? In the past If id go below 12% or so Id start getting dots on the acceleration meter and ceerrtainly by i.e. 5 or 6% Id have quite a few of those.
Nowadays I have like 1 dot which comes on at around 6 or 7% and even at i.e. 3% I only have like 3....

 

[AAKEE]

many people never go above 80% for months and have no imbalance. or like me, cycle 65% to 50% most of the time.

You mean like 0mV delta ?

I usually have 4mV in almost any case.
It never has shown 2mV as it did very shortly after the charge to 90( when to 92% if I recall it)

 

[Candleflame]

You mean like 0mV delta ?

I usually have 4mV in almost any case.
It never has shown 2mV as it did very shortly after the charge to 90( when to 92% if I recall it)

ok no SIGNIFICANT balance issues. I usually have 4mV

 

[AAKEE]

ok no SIGNIFICANT balance issues. I usually have 4mV

Just for kicks, what about charging to 90-92%, check the imbalance when charging stops and then wait for a couple of hours?

 

[Candleflame]

Just for kicks, what about charging to 90-92%, check the imbalance when charging stops and then wait for a couple of hours?

just came from a roadtrip last few days so car will sit at 60% for the next few weeks probs. will try if i remember.

 

[rhatguy]

Reopen a service request and ask them to confirm specifically that they have done exactly this check, before they close the request. I would not even mention range loss (it doesn't matter, and is entirely unrelated to whether or not your vehicle is subject to a TSB). And for exactly that reason you mention - they hear about range loss all the time, since it is universal (and completely normal and expected!), it's best to not mention it (since it doesn't matter at all until you lose 30% anyway).

It's pretty unacceptable for them to leave things ambiguous. They definitely know which vehicles are affected and should be able to tell you: "Your vehicle is not in a VIN range affected by either of these TSBs." And then you move on.

I wanted to come back and post an update to this thread about my 2018 LR AWD. Shortly after I posted to this thread back in May, my range started climbing. The only change I can attribute this to is me stopping caring about the battery. Previously I only supercharged if absolutely necessary, and never charged above 80% unless absolutely necessary. Back in May 2021, my 100% range was down ~267 miles or so. Lately I've charged the car up to 90% or even more 100% on a couple of occasions *shock* I know . I even forgot and left it charging to 90% every night for a few days *gasp*. I'm still "careful", but I've stopped worrying about it and just charge the car however I need to (super or high SOC). Over the past ~5 months, my car has gone from a low of 261 miles up to 281 today. See 2 year graph below. I can't attribute this to any reason except I just stopped caring and started using the car however made sense. Nothing else has changed. Hopefully someone with what they think is high degradation can see this post and learn something. Just use the car...don't worry about it.

 

[The Rogue]

yYou could always try voice commands. They work well for this senior.

I'm finding more and more functions can be voice actuated or changed. I agree, not taking eyes off the road is ideal. I've wondered what the engineers were thinking when designing a car that you have to take your eyes off the road to do anything. In addition, I'm not nearly as steady with my pointer finger as I used to be so I find myself stabbing several times! Recently I started asking for anything with my voice. More than ever, it works. Sometimes I have to rephrase my request differently but...try it, you'll like it. Whatever, the M3 is fun to drive! Yes, I'm a senior too.

 

[Neelk]

my tesla model 3(2020) 250 miles battery never charge fully from day one i bought it . does this happen to every one?

 

[twlatl]

I have a 2021 M3 LR and have seen significant range loss in the 10 months of ownership. I'm currently down to a top range of 316 miles from the 353 when I took ownership last December. I spoke to a Tesla Mobile Technician about it, and he stated he believed it to be bad calibration from the BMS, and that letting the battery drop to 30-40% before recharging for about a month would give the battery enough highs/lows to fix it's calibration problem. After a month of following this advice, I'm down another 5 miles.

 

[derotam]

I have a 2021 M3 LR and have seen significant range loss in the 10 months of ownership. I'm currently down to a top range of 316 miles from the 353 when I took ownership last December. I spoke to a Tesla Mobile Technician about it, and he stated he believed it to be bad calibration from the BMS, and that letting the battery drop to 30-40% before recharging for about a month would give the battery enough highs/lows to fix it's calibration problem. After a month of following this advice, I'm down another 5 miles.

So you followed their instructions, it didn't work....so you are going to contact them again to let them know the results after following their instructions right?

 

[Flybyglass]

I have a 2021 M3 LR and have seen significant range loss in the 10 months of ownership. I'm currently down to a top range of 316 miles from the 353 when I took ownership last December. I spoke to a Tesla Mobile Technician about it, and he stated he believed it to be bad calibration from the BMS, and that letting the battery drop to 30-40% before recharging for about a month would give the battery enough highs/lows to fix it's calibration problem. After a month of following this advice, I'm down another 5 miles.

I have found in my LRAWD Model 3 if I do the following I get the EPA mileage estimate - Take battery size in car (75000kw in my case) / Wh/Mi(I use 30 mile avg) from energy graph x current charge level and I get the EPA value. i.e. 75000kw/263wh/mi x .80 = 228 which is my current EPA value. If you have an 82Kw battery use 82000. Tesla had said in a recent update that the EPA number would more reflect real world driving. The question would then become is the battery capacity down or is the Wh/mi high? Also, allow the car to sleep for over 3 hours to let the BMC's do their balancing.

 

[AlanSubie4Life]

ake battery size in car (75000kw in my case) / Wh/Mi(I use 30 mile avg) from energy graph x current charge level and I get the EPA value. i.e. 75000kw/263wh/mi x .80 = 228 which is my current EPA value. If you have an 82Kw battery use 82000. Tesla had said in a recent update that the EPA number would more reflect real world driving. The question would then become is the battery capacity down or is the Wh/mi high? Also, allow the car to sleep for over 3 hours to let the BMC's do their balancing.

Original battery size in your vehicle was about 77.8kWh. I'm not even convinced your proposed method is behaving as you describe. If you're at 228 miles at 80%, that means 285 miles at 100%.

This would imply (not sure which year you have):
2018-2019 => 70kWh remaining
2020 => 69kWh remaining
2021 => 63kWh remaining

Anyway, a picture of what you're doing would help to understand. It's not valid to use a fixed value for battery capacity when using the energy graph because that is not a fixed value. In fact, the energy graph allows you to calculate your battery capacity. But it doesn't allow you to use a fixed energy value of your choosing to predict what your current displayed EPA range is.

 

[Flybyglass]

Original battery size in your vehicle was about 77.8kWh. I'm not even convinced your proposed method is behaving as you describe. If you're at 228 miles at 80%, that means 285 miles at 100%.

This would imply (not sure which year you have):
2018-2019 => 70kWh remaining
2020 => 69kWh remaining
2021 => 63kWh remaining

Anyway, a picture of what you're doing would help to understand. It's not valid to use a fixed value for battery capacity when using the energy graph because that is not a fixed value. In fact, the energy graph allows you to calculate your battery capacity. But it doesn't allow you to use a fixed energy value of your choosing to predict what your current displayed EPA range is.

Interesting, using my method I get the EPA number and using your KW values on a 2020 I get 209 which is the estimated range on the right side of the graph. I attribute the variance to reservers held back by Tesla. BTW 285 is what my app shows at 100%. I also attribute the high Wh/mi due to living in a hilly area. Too many mathematical correlations here to be by chance.

 

[AlanSubie4Life]

Interesting, using my method I get the EPA number and using your KW values on a 2020 I get 209 which is the estimated range on the right side of the graph. I attribute the variance to reservers held back by Tesla. BTW 285 is what my app shows at 100%. I also attribute the high Wh/mi due to living in a hilly area. Too many mathematical correlations here to be by chance.

If you post a picture we can go through the math. (You'll need to include one picture with % mode (energy), and another with miles mode (distance).)

 

[AlanSubie4Life]

Too many mathematical correlations here to be by chance.

Yeah, actually it's just by chance. Assuming your car has 285mi @100% with a 2020 Model 3 LR, you have about 68.8kWh at a full charge.

(1) 68.8kWh*0.8/263Wh/mi = 209mi (what the energy screen will say you have as projected range, with EPA range displayed of 228mi)

(2) 75kWh*0.8/263Wh/mi = 228mi (which is purely a coincidence, since your battery does not have 75kWh capacity. It just so happens that 263Wh/mi/241.6Wh/mi ~= 75kWh/68.8kWh)

If you want to verify, just pick a very different recent consumption value (say, 200Wh/mi) and see what you get. You'll see formula (1) matches the results.

For your vehicle right now, use 68.8kWh*SoC%/241.6Wh/mi = 285mi*SoC% to give you your current displayed rated miles. (Worth noting however that 68.8kWh*SoC% is NOT exactly your remaining energy though, except at 100% SoC...)

Or if you want to predict it from the energy screen:

Projected Range * Recent Efficiency / 241.6Wh/mi.

So for example at 80% SoC, if you're at 200Wh/mi recently, you'll see the energy screen predict 275mi range. And you can calculate for a 2020 LR Model 3 (the formula is different for other vehicles) what the EPA displayed remaining range will be:

275mi * 200Wh/mi / 241.6Wh/rmi = 228rmi. (That's what the displayed remaining range will be.)

And actual energy remaining at that point would be 0.045*68.8kWh + 0.955*68.8*0.8 = 55.7kWh (not 275mi*200Wh/mi = 55kWh). Due to the way the buffer is accounted for.

 

[Flybyglass]

Yeah, actually it's just by chance. Assuming your car has 285mi @100% with a 2020 Model 3 LR, you have about 68.8kWh at a full charge.

(1) 68.8kWh*0.8/263Wh/mi = 209mi (what the energy screen will say you have as projected range, with EPA range displayed of 228mi)

(2) 75kWh*0.8/263Wh/mi = 228mi (which is purely a coincidence, since your battery does not have 75kWh capacity. It just so happens that 263Wh/mi/241.6Wh/mi ~= 75kWh/68.8kWh)

If you want to verify, just pick a very different recent consumption value (say, 200Wh/mi) and see what you get. You'll see formula (1) matches the results.

For your vehicle right now, use 68.8kWh*SoC%/241.6Wh/mi = 285mi*SoC% to give you your current displayed rated miles. (Worth noting however that 68.8kWh*SoC% is NOT exactly your remaining energy though, except at 100% SoC...)

Or if you want to predict it from the energy screen:

Projected Range * Recent Efficiency / 241.6Wh/mi.

So for example at 80% SoC, if you're at 200Wh/mi recently, you'll see the energy screen predict 275mi range. And you can calculate for a 2020 LR Model 3 (the formula is different for other vehicles) what the EPA displayed remaining range will be:

275mi * 200Wh/mi / 241.6Wh/rmi = 228rmi. (That's what the displayed remaining range will be.)

And actual energy remaining at that point would be 0.045*68.8kWh + 0.955*68.8*0.8 = 55.7kWh (not 275mi*200Wh/mi = 55kWh). Due to the way the buffer is accounted for.

Well done. I follow all of this except where did 241.6 wh/mi come from?

 

[AlanSubie4Life]

Well done. I follow all of this except where did 241.6 wh/mi come from?

241.6Wh/mi is 77.8kWh/322mi