USA MY RWD has soft limited LR battery!

[3sr+buyer]

From what I have read, my understanding is that both high and low states of charge increase wear on the battery. You'll often see the advice to try and use the 20%-80% charge state in general for lithium ion batteries.

Low state of charge (but not below 0%) is actually good for minimizing degradation. But most drivers are not that good at estimating if they can get home or to the next charging opportunity with 0-1% left, so advice not to go too low is more for avoiding the driver's range anxiety and risk of running completely empty than for battery preservation. For the latter reason, Tesla fudges the battery percentage / rated range display to show 0% a few percent before the actual 0% is reached when the car shuts down to protect the battery.

 

[bzobzo]

Looks like the LR battery pack to me.

Edit: looks like the the older 78kWh pack, starting in 2021 they started using 82kWh packs. That would make sense that they would use up the older 78kWh packs they had laying around.

 

[ven7782]

Waiting for my MY RWD with VIN: 7SAYGDED8PF945XXX The F indicates it is Fremont built. Expected delivery is anytime now. If it is indeed the LR battery pack which is SW limited to 260 miles, its great news. Does Tesla recommends charging it to 80% to fool us? Because technically you can charge it to 100% each time with no side effects correct?

 

[E90alex]

Waiting for my MY RWD with VIN: 7SAYGDED8PF945XXX The F indicates it is Fremont built. Expected delivery is anytime now. If it is indeed the LR battery pack which is SW limited to 260 miles, its great news. Does Tesla recommends charging it to 80% to fool us? Because technically you can charge it to 100% each time with no side effects correct?

Lower is always better for battery health.

 

[kpanda17]

Waiting for my MY RWD with VIN: 7SAYGDED8PF945XXX The F indicates it is Fremont built. Expected delivery is anytime now. If it is indeed the LR battery pack which is SW limited to 260 miles, its great news. Does Tesla recommends charging it to 80% to fool us? Because technically you can charge it to 100% each time with no side effects correct?

That’s where I am at
It would give the RWD a BG value boost if it’s true

 

[ven7782]

Lower is always better for battery health.

100% of SW limited LR is still less than 80% of LR. How does it matter?

 

[E90alex]

100% of SW limited LR is still less than 80% of LR. How does it matter?

And 80% would be more like ~65%. Lower average SoC is better for battery health.

Below ~55% is best if that’s enough range for your needs. No need to charge to 100 or even 80 if you only use 10-20% a day, for example.

 

[kpanda17]

And 80% would be more like ~65%. Lower average SoC is better for battery health.

Below ~55% is best if that’s enough range for your needs. No need to charge to 100 or even 80 if you only use 10-20% a day, for example.

For road trips, can we treat this battery like LFP and run rhe SOC 100%down to 5% achieving approx 247 miles vs if just sized for exactly 260 miles and can only use 5 to 80% or 195 miles?

 

[E90alex]

Road trips you can charge to whatever you want or need.

Charging recommendations to minimize battery degradation are generally just for daily use where it’s most likely going to be sitting parked for many hours near those charge levels.

 

[kpanda17]

Are these rhe qtys weve been looking for?

LR pack capped at 78?
if true we can charge to 100% whenever desired
great value for an SUV at 247 miles of real range

 

[jsight]

Looks like the LR battery pack to me.

Edit: looks like the the older 78kWh pack, starting in 2021 they started using 82kWh packs. That would make sense that they would use up the older 78kWh packs they had laying around.


View attachment 1001867

The older packs were 74kwh with usable at a little less than 70.

The update was to 82kwh, with usable closer to 75kwh, iirc.

 

[jcanoe]

The older packs were 74kwh with usable at a little less than 70.

The update was to 82kwh, with usable closer to 75kwh, iirc.

I have an early 2020 LRMY that came with a printout from Tesla stating that the usable capacity (when new) was 74kWh (This paperwork documented the usable capacity of the battery for a rebate program that was in effect at the time in Maryland.) I always understood the total capacity to be ~77 to78kWh. Later Tesla added ~4.5kWh to the LR and P battery for ~82kWh total capacity (78 to 79kWh usable.)

 

[bzobzo]

I have an early 2020 LRMY that came with a printout from Tesla stating that the usable capacity (when new) was 74kWh (This paperwork documented the usable capacity of the battery for a rebate program that was in effect at the time in Maryland.) I always understood the total capacity to be ~77 to78kWh. Later Tesla added ~4.5kWh to the LR and P battery for ~82kWh total capacity (78 to 79kWh usable.)

I think you are right on this. In researching this some more, I'm reading that ScanYourTesla reports the 82kWh battery as 78-79kWh, as that is the usable capacity. There is another 3 kWh or so allocated to the buffer which when added to the usable capacity totals 82kWh.

Given this, it looks like the RWD does have the current 82kWh pack of the LR. Also, the RWD seems to have more access to the capacity than one would expect from the range rating. In theory, 260 miles / 330 miles * 79kWh should result in a 62KWh capacity. However, the energy app seems to think the car has access to 69kWh (for example right now the average consumption in my car is shown as 216kWh/mile with a 115 mile estimated range with 36% battery). If that is the case, then only 12% or so is being limited, and this would line up with the fast charging behavior where at 99% the RWD has a similar charge rate as the LR at around 90%.

 

[id_unknown]

AlanSubie4Life post from 2021:

Basically, AFAIK, 2021:
Performance: FPWN 82.1kWh (seems to be limited to about 81kWh)
AWD: FPWN 77.8kWh (no apparent limitation, typically will see around that for a new vehicle with a full pack)

The SMT FPWN (Full Pack When New) is a hard-coded value. The Nominal Full Pack is your vehicle's actual maximum capacity.

The energy screen method provides the Nominal Full Pack value.
There is vehicle-to-vehicle variation in starting capacity too, so I'd expect something like +/-1kWh typically around these starting numbers, for a new vehicle. Though it's pretty rare to see the +1kWh side of things.

It appears that they have Model 3 LR batteries, not 82 kWh pack.

 

[jcanoe]

I think you are right on this. In researching this some more, I'm reading that ScanYourTesla reports the 82kWh battery as 78-79kWh, as that is the usable capacity. There is another 3 kWh or so allocated to the buffer which when added to the usable capacity totals 82kWh.

Given this, it looks like the RWD does have the current 82kWh pack of the LR. Also, the RWD seems to have more access to the capacity than one would expect from the range rating. In theory, 260 miles / 330 miles * 79kWh should result in a 62KWh capacity. However, the energy app seems to think the car has access to 69kWh (for example right now the average consumption in my car is shown as 216kWh/mile with a 115 mile estimated range with 36% battery). If that is the case, then only 12% or so is being limited, and this would line up with the fast charging behavior where at 99% the RWD has a similar charge rate as the LR at around 90%.

I always refer back to this earlier post, example (nod to @scottf200) of estimating the capacity of a Model X battery. The most important take away is that this method of estimating the usable capacity of the Tesla battery is that the state of charge when viewing the energy screen should be greater than or equal to 80% for best accuracy.

Calculating Your Battery's Estimated Capacity Using the Car's Energy Screen

 

[ucmndd]

Also, the RWD seems to have more access to the capacity than one would expect from the range rating. In theory, 260 miles / 330 miles * 79kWh should result in a 62KWh capacity.

We should also expect some difference in efficiency of the RWD vs AWD platform, which might explain it.

 

[ven7782]

Given that the MY RWD has a SW limited LR battery pack, how will this impact battery degradation? Will that be also done via software? Technically the RWD battery will not degrade below 260 miles for a long time so the plus side is that there will be no battery degradation.

 

[MP3Mike]

Given that the MY RWD has a SW limited LR battery pack, how will this impact battery degradation? Will that be also done via software? Technically the RWD battery will not degrade below 260 miles for a long time so the plus side is that there will be no battery degradation.

That isn't how it works. They limit the state of charge to a specific %, not to a specific range/energy level. So, degradation will be pretty much the same as a non-limited pack. (Calendar aging degradation should be pretty much the same, but overall degradation might be a little lower since the state of charge will be lower.)

 

[ven7782]

So if I do the math and assume a 5% drop in the first year, 95% of 330 is 313 miles. Now the SW will limit it to 80% of 313 after the first year which is 250 miles correct?

 

[gsmith123]

That isn't how it works. They limit the state of charge to a specific %, not to a specific range/energy level. So, degradation will be pretty much the same as a non-limited pack. (Calendar aging degradation should be pretty much the same, but overall degradation might be a little lower since the state of charge will be lower.)

Side note: why don’t they do this?

Battery degradation is a concern for people, especially on a 260 mile range car. Seems like they could mitigate this essentially for free for the cars that need it most.