USA MY RWD has soft limited LR battery!

[jsight]

I have a MY RWD ordered but honestly having cold feet thereafter. I am very concerned about the range for in the longer term. In 5 or 6 years I dont want to make a bunch of charging stops when I go to a neighboring city.

I've also updated to Michelin cc2 tires and that cuts into range as well.

But this is all pretty insignificant. If I wasn't measuring it, I might not have noticed. The real world impact is 5-10 minutes longer at superchargers on days with 5+ hours of driving.

I think we overstate the significance of small differences in range sometimes.

 

[ucmndd]

I am not buying an EV to travel from city to city. I like most folks am buying for my daily commute to work. I know the route better and will never have a range anxiety. 98% of my driving is local/commute to work and I like that odds.

Why not both?

Unless your “neighboring city” is like 300 miles away, and even if it is, this just isn’t an issue for a car with 200+ miles range and the supercharger network.

 

[bzobzo]

More good news for RWD owners. The charge rate is not limited to 170kW. I saw 215kW at a 20% SOC. Here are the charge rates from my SC session today from 20% to 80%

20% - 215kW
30% - 177kW
40% - 148kW
50% - 120kW
60% - 98kW
70% - 80kW
80% - 71kW

The LR can only manage 250kW for a brief moment near 10% SOC and the rest of the LR charge curve is similar to the above, so I expect the RWD will also be able to pull down 250kW at a lower SOC.

However, even if the charging was limited to 170kW, it doesn't matter much. A rate greater than that can only be sustained for such a brief time, it doesn't make much difference in the charging time.

 

[icu2023]

More good news for RWD owners. The charge rate is not limited to 170kW. I saw 215kW at a 20% SOC. Here are the charge rates from my SC session today from 20% to 80%

20% - 215kW
30% - 177kW
40% - 148kW
50% - 120kW
60% - 98kW
70% - 80kW
80% - 71kW

The LR can only manage 250kW for a brief moment near 10% SOC and the rest of the LR charge curve is similar to the above, so I expect the RWD will also be able to pull down 250kW at a lower SOC.

However, even if the charging was limited to 170kW, it doesn't matter much. A rate greater than that can only be sustained for such a brief time, it doesn't make much difference in the charging time.

so, at this point, can we be sure that MY RW uses the same LR battery pack?

 

[bzobzo]

so, at this point, can we be sure that MY RW uses the same LR battery pack?

I believe that it is the same. Scan My Tesla shows the same total battery capacity as the LR and the charge curve is what you would expect from the LR battery.

In fact I think the battery pack may be soft limited less than originally assumed. I checked from several different states of charge, and I'm seeing the Energy App thinking there is 69-70kWh of battery capacity available. That would make it about 89% of the 78kWh available in the LR. The charge curve also is what you would expect from charging a LR from low SOC to 90%.

If this is true, the advertised range on the RWD is underrated and the range may be closer to 300 miles. (330 * .89 plus a bit more because the RWD drivetrain is more efficient than the AWD). Anecdotally one of the early RWD owners who also drives a LR reported that the RWD was getting more range than expected.

 

[ucmndd]

so, at this point, can we be sure that MY RW uses the same LR battery pack?

It sure appears that way.

At least for now - it strikes me that maybe they were planning for an introduction with a different pack some time in the near future but decided to pull the release forward to stimulate demand. In theory they could switch over to a different pack that meets the published specs at any time.

 

[tunnu]

I believe that it is the same. Scan My Tesla shows the same total battery capacity as the LR and the charge curve is what you would expect from the LR battery.

In fact I think the battery pack may be soft limited less than originally assumed. I checked from several different states of charge, and I'm seeing the Energy App thinking there is 69-70kWh of battery capacity available. That would make it about 89% of the 78kWh available in the LR. The charge curve also is what you would expect from charging a LR from low SOC to 90%.

If this is true, the advertised range on the RWD is underrated and the range may be closer to 300 miles. (330 * .89 plus a bit more because the RWD drivetrain is more efficient than the AWD). Anecdotally one of the early RWD owners who also drives a LR reported that the RWD was getting more range than expected.

On reddit user had posted they got 240 miles on charging 100%.

 

[bzobzo]

It sure appears that way.

At least for now - it strikes me that maybe they were planning for an introduction with a different pack some time in the near future but decided to pull the release forward to stimulate demand. In theory they could switch over to a different pack that meets the published specs at any time.

I think so too. Either this is an experiment to see if the trim makes sense and they didn't want to invest much development into it, or this is an temporary substitution to meet the battery requirements for the federal EV credit. If the RWD sticks around, I fully expect them to switch to a lower capacity battery and perhaps reduced features like the M3 RWD. But for now, the RWD appears to be identical to the LR minus the front drivetrain and some software limits on the battery and use of the fog lights (LOL).

 

[bzobzo]

I found the EPA certification documents for the M3 and MY RWD.

Here is the M3 EPA certication: 2023 M3 RWD
it lists a 350V pack with 174A capacity.

Here is the MY EPA certification: 2023 MY RWD
it also lists a 350V pack with 174A capacity.

The NCA packs on the LR are 360V with a higher capacity. It appears they were originally going to use the same LFP pack from the M3 RWD, but swapped to the LR packs at the last minute to keep the EV credit.

 

[Mrbrock]

I have a CAN cable on order for use with ScanMyTesla, so hopefully I'll be able to report some more data soon.

I think the use of the LR battery was primarily motivated by trying to keep the RWD eligible for the tax credit. However, since they didn't have an off the shelf smaller NCA pack, they used the existing LR one. From the teardown videos I've seen of the battery pack, it doesn't look like a simple change to simply leave out some cells. And given the transition to the new 4680 cells, they probably didn't want to engineer, certify and stock a new smaller NCA pack on the soon to be outdated 2170 cells. I'd be surprised if they didn't transition to a cheaper smaller capacity battery pack soon though, because at $100/kWh, the roughly 20kWh extra in the larger pack is a fair chunk of change. But given the effective $7500 off the purchase price of the vehicle with the tax credit, I suppose they deemed the extra cost tolerable for now.

They had a small SR 2170 MY battery in 2020. And SR+ M3 since introduction. Made in Reno. They didn’t forget how to make those so they wouldn’t need to engineer one. But they likely removed all the tooling to make these so it’s cheaper from a miniaturing standpoint to software limit than the change out production line tools.

Is there any way these could be LR batteries that just don’t show the required capacity to meet LR specs so they get downgraded to SR?

 

[ven7782]

I believe that it is the same. Scan My Tesla shows the same total battery capacity as the LR and the charge curve is what you would expect from the LR battery.

In fact I think the battery pack may be soft limited less than originally assumed. I checked from several different states of charge, and I'm seeing the Energy App thinking there is 69-70kWh of battery capacity available. That would make it about 89% of the 78kWh available in the LR. The charge curve also is what you would expect from charging a LR from low SOC to 90%.

If this is true, the advertised range on the RWD is underrated and the range may be closer to 300 miles. (330 * .89 plus a bit more because the RWD drivetrain is more efficient than the AWD). Anecdotally one of the early RWD owners who also drives a LR reported that the RWD was getting more range than expected.

Before I get ahead of myself, I am taking delivery of MY RWD tomorrow. Do we know the probable time period that Tesla put LR batteries in RWD? I will check the charge rate as stated here on my car to make sure. When did they start and will possibly end putting these batteries on RWD?

 

[gsmith123]

The Model Y RWD has only been out since early October (source).

(Note: before that they offered the AWD standard range using 4680 cells and even further back there was an earlier generation of RWD Model Y a few years ago)

It seems likely all of them since introduction in October probably are the LR packs. And as far as we know they are still doing it, but that could change any second...

 

[PeterAAA]

I was wondering the same. The worst scenario could be that these are remanufactred battery packs from warranty claims. But it is unlikely. If this is confirmed, Tesla will get sued for selling old parts as new.

 

[ven7782]

The Model Y RWD was reintroduced in Oct. It had existed before but was pulled. It is possible that the reintroduced one has the LR battery.

 

[ucmndd]

I was wondering the same. The worst scenario could be that these are remanufactred battery packs from warranty claims. But it is unlikely. If this is confirmed, Tesla will get sued for selling old parts as new.

No company on earth, not even Tesla, would take that risk. This scenario is not something to worry about or even think about whatsoever.

 

[icu2023]

I found the EPA certification documents for the M3 and MY RWD.

Here is the M3 EPA certication: 2023 M3 RWD
it lists a 350V pack with 174A capacity.

Here is the MY EPA certification: 2023 MY RWD
it also lists a 350V pack with 174A capacity.

The NCA packs on the LR are 360V with a higher capacity. It appears they were originally going to use the same LFP pack from the M3 RWD, but swapped to the LR packs at the last minute to keep the EV credit.

It looks like the actual MY RWD sold uses different battery pack and has different curb weight from what were documented in the EPA certificate. How could they still sell the cars with this non-applicable EPA certificate? Is there an updated MY RWD EPA certificate?

 

[stopcrazypp]

It looks like the actual MY RWD sold uses different battery pack and has different curb weight from what were documented in the EPA certificate. How could they still sell the cars with this non-applicable EPA certificate? Is there an updated MY RWD EPA certificate?

The battery specs on the EPA certificates don't seem to matter, a lot of them have inaccurate specs on it. Seems to just be secondary placeholder info. The test results are what seem to matter.

 

[bzobzo]

Before I get ahead of myself, I am taking delivery of MY RWD tomorrow. Do we know the probable time period that Tesla put LR batteries in RWD? I will check the charge rate as stated here on my car to make sure. When did they start and will possibly end putting these batteries on RWD?

I would guess we won't see any change on this until Tesla has a solution that meets the tax credit requirements or if they give up on keeping the credits. When we start to hear about a SR M3 that will meet the tax credit requirements or warning about losing the credit for the MY, would be when I would guess a change for the battery on the MY RWD is near.

 

[kpanda17]

M2 will change everything with the bottom trim at $25K, the pressure will be off the M3 bottom trim at $32K (Tesla will have to lower before the highland shows up) then it back up to $40 and MY bottom trim at $42K until Jupiter shows up allowing the Y to goto $45K after
where the M2 with 4680s will be the only Tesla, on the low end, to get tax credit, $25 less $7500 plus your state, or max potential $25K less $15K or $10K OTD
Wow

 

[PeterAAA]

The battery specs on the EPA certificates don't seem to matter, a lot of them have inaccurate specs on it. Seems to just be secondary placeholder info. The test results are what seem to matter.

The EPA certificate was issued in May. The test was done probably in April. I don’t think Tesla knew about the tax credit changes at that time and already swapped the battery packs. I think the test cars actually used 60kwh LFP packs as the specs suggested in the certificate.
Additionally, the curb weight does not match either.
There should be an updated EPA certificate or amendment that was not published online.
If Tesla wants to hide the fact that they used LR pack so that LR model sales won’t be affected, they could have requested EPA not to make the test report public.