Battery Degradation Fixed by Long Distance Driving...

[Arx001]

Hello,

My 2019 Model X LR is used for short distances occasionally and has relatively few kms (32,000 km - 20,000 miles) on it. In order to maximize battery life I always charged at home using low amperage within a 20-75% regime.

Recently I started using the car more often and its range was really low like 55% of the brand new / published range. I communicated with Tesla and asked for a battery replacement from warranty but they said the battery was fine. They suggested that I fully charge the car and do some long distance driving so the battery will recondition itself. I was suspicious because I thought I was being dismissed however several long distance drives (but on the shorter end like 300 km / 200 miles) made some difference so the range has gone up to around 75%.

My question is does short (or very short) distance driving degrade the battery and can the opposite be true for long distance driving? I'm familiar with the factors that diminish range such as speed, elevation, acceleration, temperature but never considered driving distance to be a factor.

Thanks for your sharing your experience and advice!

 

[someguywithcar]

There are two parts to this. The battery and the battery management system (bms).

Tesla is saying your battery itself, the lithium based electricity holder, is still working in spec. You aren’t fixing it or removing degradation.

The bms is the software that tells you how much electricity and range is in the battery. It’s kind of like the bms gets lazy if it only hangs out in a narrow band of % charge. So filling up your car to a high state of charge and then driving it to a low state of charge help it remember the % better. This isn’t fixing the battery but instead calibrating the software that manages the battery.

 

[AAKEE]

My question is does short (or very short) distance driving degrade the battery and can the opposite be true for long distance driving?

Nope.

The general rule is: The smaller the cycles, the lower the cyclic aging.

This is model 3 cells cycled 0-100, 0-50 and 50-100% (R = room temp, H = high temp)
The one that did hold up best had lost 20% after 2500 FCE, and the 0-100% had lost 25% after 1000 cycles.

This is model 3 cells, even from the same car I think, that was cycled with only 10% depth of discharge:

The cycling option that held up worst (5-15%) had lost 17% after 3000FCE.
(5-15% real SOC equals 0-10% on a Tesla screen due to the buffer below 0% displayed on a Tesla).

3000FCE equals ~ 3000 x 400 km so 1.200.000 km. With only 17% lost.
So transfered to normal use, about 0.3% cyclic wear each year.

So, now we know that cycles will not wear very much.
The thing that causes the most degradation is calendar aging.

For the cars battery computer, the BMS, it could help the estimation of the battery capacity to have the car sleeping at both low and high SOC (search for BMS Calibration here on TMC).

This could help the BMS to better estimate, but it will not really regain any capacity, only (perhaps) increasing the displayed range.

 

[Rocky_H]

Recently I started using the car more often and its range was really low like 55% of the brand new / published range. I communicated with Tesla and asked for a battery replacement from warranty but they said the battery was fine.

Could you explain in more detail of what is actually happening here, because this can't be possible. Let's say original range for the car showed 300 rated miles when fully charged (made up number). If as you say the range is now 55%, then when fully charged, it could only show 165 rated miles on the display. Something is drastically broken if that is the case, and Tesla's degradation warranty guarantees it won't be below 70% during the warranty period, so they would say it's bad if that were happening and not say it's fine.

The battery system's estimation software can get off a bit, but that's like 10 to 15%, not 45%.

So is this just that you did some driving over the course of several days and all of that cumulative use put together only equaled 55% real miles versus what it originally had on the display?

 

[Arx001]

Could you explain in more detail of what is actually happening here, because this can't be possible. Let's say original range for the car showed 300 rated miles when fully charged (made up number). If as you say the range is now 55%, then when fully charged, it could only show 165 rated miles on the display. Something is drastically broken if that is the case, and Tesla's degradation warranty guarantees it won't be below 70% during the warranty period, so they would say it's bad if that were happening and not say it's fine.

The battery system's estimation software can get off a bit, but that's like 10 to 15%, not 45%.

So is this just that you did some driving over the course of several days and all of that cumulative use put together only equaled 55% real miles versus what it originally had on the display?

I was unaware of the advanced discussions here and just did a basic math based on kms driven like I drive 260 kms instead of 550 kms on a 100% charge. I calculated 56% because the car drove 56% of the original range. I understand the battery has a limited life and I also did not account or calculate other factors including elevation changes but the car was test driven in a minimum consumption basis without the seat heaters etc. Plus the Tesla app's range analysis showed serious degradation below the EPA line but I have no idea how to comment on it.

 

[Arx001]

There are two parts to this. The battery and the battery management system (bms).

Tesla is saying your battery itself, the lithium based electricity holder, is still working in spec. You aren’t fixing it or removing degradation.

The bms is the software that tells you how much electricity and range is in the battery. It’s kind of like the bms gets lazy if it only hangs out in a narrow band of % charge. So filling up your car to a high state of charge and then driving it to a low state of charge help it remember the % better. This isn’t fixing the battery but instead calibrating the software that manages the battery.

Thank you this helps!

 

[Arx001]

"For the cars battery computer, the BMS, it could help the estimation of the battery capacity to have the car sleeping at both low and high SOC (search for BMS Calibration here on TMC)."
Thank you @AAKEE

 

[Rocky_H]

I was unaware of the advanced discussions here and just did a basic math based on kms driven like I drive 260 kms instead of 550 kms on a 100% charge. I calculated 56% because the car drove 56% of the original range. I understand the battery has a limited life and I also did not account or calculate other factors including elevation changes but the car was test driven in a minimum consumption basis without the seat heaters etc. Plus the Tesla app's range analysis showed serious degradation below the EPA line but I have no idea how to comment on it.

Oh, OK, thanks for the better understanding of it. That's not degradation of the battery's capability to hold energy at all then. It's just very high energy consumption during use.

 

[KenBlub]

I have followed the advice of @AAKEE for the 8.5 months I’ve had my 2023 model 3 LR. Only charged above 55% 4-5x for a trip and usually driven 25-30% per day. For the first time ever I charged to 100% for a long trip just before leaving. It said 331 rated miles when I opened the door and 333 when I put the car in reverse. That can’t be right because my energy screen shows 77.5kw but even if we go by the energy screen that’s only 1.6 or 1.7% degradation.

 

[AAKEE]

I have followed the advice of @AAKEE for the 8.5 months I’ve had my 2023 model 3 LR. Only charged above 55% 4-5x for a trip and usually driven 25-30% per day. For the first time ever I charged to 100% for a long trip just before leaving. It said 331 rated miles when I opened the door and 333 when I put the car in reverse. That can’t be right because my energy screen shows 77.5kw but even if we go by the energy screen that’s only 1.6 or 1.7% degradation.

It’s the LR witht the reduced EPA-range and the LG battery, right? 333 miles EPA-range, and a 78.8kWh LG battery.

The 77.5kWh matches the cars I know about with the same battery that has used low SOC. Around 78kWh capacity after one year, but I think we have it slightly colder up here so 77.5 looks just like we would expect.

 

[AlanSubie4Life]

I have followed the advice of @AAKEE for the 8.5 months I’ve had my 2023 model 3 LR. Only charged above 55% 4-5x for a trip and usually driven 25-30% per day. For the first time ever I charged to 100% for a long trip just before leaving. It said 331 rated miles when I opened the door and 333 when I put the car in reverse. That can’t be right because my energy screen shows 77.5kw but even if we go by the energy screen that’s only 1.6 or 1.7% degradation.

The degradation threshold of the late-2023 Model 3 LR with LG 78.8kWh (FPWN - Full Pack When New) pack and 333-rated-mile EPA range is about 77.9kWh.

So this means the energy screen cannot show a value in excess of 77.9kWh even if your pack exceeds this energy content.

If that energy screen value you state as 77.5kWh corresponded to the 331mi value, then it all makes sense to see 77.5kWh.

331mi/333mi*77.9kWh = 77.4kWh (77.5kWh)

Most likely the energy screen showed closer to 77.9kWh when the screen displayed 333 rated miles.

So relative to wherever you started (which we don’t know for your car, but may be around 78.8 kWh, maybe @AAKEE has a better idea of SMT typical), you are around 1% loss. Maybe. Hard to know because of conflicting datapoints you read out above, but I am assuming that means you are right at the threshold.

Keeping low SOC seems to be working well for you. Keep happily charging to 100% (briefly) for road trips! Not an issue. Best of both worlds. Maximum energy content of the pack, maximum road-trip utility, no impact on daily utility.

 

[KenBlub]

The degradation threshold of the late-2023 Model 3 LR with LG 78.8kWh (FPWN - Full Pack When New) pack and 333-rated-mile EPA range is about 77.9kWh.

So this means the energy screen cannot show a value in excess of 77.9kWh even if your pack exceeds this energy content.

If that energy screen value you state as 77.5kWh corresponded to the 331mi value, then it all makes sense to see 77.5kWh.

331mi/333mi*77.9kWh = 77.4kWh (77.5kWh)

Most likely the energy screen showed closer to 77.9kWh when the screen displayed 333 rated miles.

So relative to wherever you started (which we don’t know for your car, but may be around 78.8 kWh, maybe @AAKEE has a better idea of SMT typical), you are around 1% loss. Maybe. Hard to know because of conflicting datapoints you read out above, but I am assuming that means you are right at the threshold.

Keeping low SOC seems to be working well for you. Keep happily charging to 100% (briefly) for road trips! Not an issue. Best of both worlds. Maximum energy content of the pack, maximum road-trip utility, no impact on daily utility.

Thanks Alan. Yes, mine is the LG 78.8. I've really enjoyed learning about these cars from you as well. I'm very lucky that my lifestyle and daily driving needs allow me to be fairly rigorous about a low SOC.

I didn't do an energy calculation after I put the car in reverse. Any idea why it jumped from 331 to 333 after putting the car in reverse?

 

[AlanSubie4Life]

Any idea why it jumped from 331 to 333 after putting the car in reverse?

Probably just modifying the estimate of how full the battery is. These values are surprisingly stable. Maybe you were just below 100% at the 331 value (or maybe actually 99%). It is hard to say without comprehensive pictures (or a video).

I doubt it reassessed your nominal full pack since the car was not sleeping.

Regardless, a display of 333 implies very close to 77.9kWh, and possibly exceeding that.

 

[AAKEE]

So relative to wherever you started (which we don’t know for your car, but may be around 78.8 kWh, maybe @AAKEE has a better idea of SMT typical), you are around 1% loss. Maybe. Hard to know because of conflicting datapoints you read out above, but I am assuming that means you are right at the threshold.

Yes, the LG has been known to start ”low” and increase the capacity during a couple of months or so (probably depending on theusage of the car).

Often starts below 78.8 and ends at above 79 after a couple of months and then start the degradation (all according to the BMS numbers).

While I havent done any capacity calc on a new Tesla with the LG i suspect that the cycling process during the manufacturing process is not done until the maximum capacity occurs, so the first time of ownership does it instead. So the reason for increasing the capacity numbers could be that the capacity reasly increases
(In opposite to my Model S which started with low BMS capacity estimate but the capacity was already there from day 1.)

 

[AAKEE]

I didn't do an energy calculation after I put the car in reverse. Any idea why it jumped from 331 to 333 after putting the car in reverse?

The BMS need to see the battery without any load before being able to judge the SOC precicely after a charge.

I would guess that the junämp to 333 came at the time when the BMS had the data to update the capacity estimate.
Probably quite short time after the charge was finished, and the door opening/reverse selection had actually nothing to do with it.

 

[DCGOO]

The BMS need to see the battery without any load before being able to judge the SOC precicely after a charge.

I would guess that the junämp to 333 came at the time when the BMS had the data to update the capacity estimate.
Probably quite short time after the charge was finished, and the door opening/reverse selection had actually nothing to do with it.

The other thing to keep in mind is, the point at which charging stops, is not always the same. I have both our cars set to charge to 75% at home, overnight. When I start out in the morning, I will have anywhere between 73% and 78% on our X, our Model 3 is even more variable. If you are watching miles instead of the recommended % soc, it could vary anywhere in +/- 15. So a variance of a few miles is simply negligible and should be ignored. The system is simply not particularly precise.

 

[AAKEE]

The other thing to keep in mind is, the point at which charging stops, is not always the same. I have both our cars set to charge to 75% at home, overnight. When I start out in the morning, I will have anywhere between 73% and 78% on our X, our Model 3 is even more variable. If you are watching miles instead of the recommended % soc, it could vary anywhere in +/- 15. So a variance of a few miles is simply negligible and should be ignored. The system is simply not particularly precise.

I do not se any variation, except if the car is out in the cold and the battery has cooled down, then the car deliberatly shows a lower SOC.

 

[KenBlub]

Thanks. Mine was set to 100% and it sat for an hour and it was still 100 when I left