SR & SR+ Battery Questions & Thoughts

[Rocky_H]

Space filling material.

I appreciate your informative tips while also carefully keeping clear of NDA type secret sauce.

 

[GigaGrunt]

I appreciate your informative tips while also carefully keeping clear of NDA type secret sauce.

Essentially a ‘knuckle’. Injection molded plastic grid that fills space, and allows some type of structural support.

 

[peakshaving]

Essentially a ‘knuckle’. Injection molded plastic grid that fills space, and allows some type of structural support.

Alright as long as it wasn't schleem I'm happy.

 

[darth_vad3r]

No dummy cells in 'new' SR/SR+ packs. Lower brick density is less cells per brick.

Technically that’s not “lower density” ... if the size of the SR bricks is smaller with less cells than the larger LR bricks with more cells, it can be the same density, just smaller size.

Based on photos/diagrams I’m guessing one zig-zaggy “row” (or column) got removed from the LR 46-cell brick pattern to make a shorter (narrower) 31-cell SR brick pattern. I would expect all of the SR’s module’s cells to be packed in the exact same way as LR with the cooling going through them all the same until you reach 31/46th the length of the module from the rear, and then filler material starts.

Really the cells would look identical from the rear til the filler material. It would only be the the plates connecting them in parallel in groups of 31 vs 46 that would be different (and electrical connections, etc) ... if you tore down an LR vs an SR to the point just the cells and goop were visible I doubt you could tell the difference* if you had a crop that showed only the first couple hundred cells in the module. Or the first 700-ish even. 744 cells in one SR module (31p x 24s).

EDIT:
*Ah no, wait ... you could tell the difference because each consecutive brick is oriented upside down from the prior one IIRC.

EDIT2:
Crappy ASCII art diagram... (only one 46-cell ‘+’ up top down view is ‘accurate’ (count is right), neighbouring ‘-‘ up not all depicted)...
+.+.+.+.-.-...
.+.+.+.-.-.-...
-.+.+.+.-.-...
.+.+.+.-.-.-...
+.+.+.+.-.-.-...
.+.+.+.-.-.-...
-.+.+.+.-.-.-...
.+.+.+.-.-.-...
+.+.+.+.-.-.-...
.+.+.+.-.-.-...
-.+.+.+.-.-...
.+.+.+.-.-.-...
+.+.+.+.-.-.-...
.+.+.+.-.-.-...

For a 31-cell brick pattern my guess would be:
+.+.-.-...
.+.+.-.-...
-.+.+.-.-...
.+.+.-.-...
+.+.+.-.-...
.+.+.-.-...
-.+.+.-.-...
.+.+.-.-...
+.+.+.-.-...
.+.+.-.-...
-.+.+.-.-...
.+.+.-.-...
+.+.+.-.-...
.+.+.-.-...

 

[darth_vad3r]

I hadn’t thought about all the different module configurations before. LR would have two different module configs (inside and outside) and SR would have another two, unless they designed the four SR modules to all be the same size and be interchangeable into any of the four positions. They probably had room for that so that’s where I’ll put my money.

That would be just three unique module designs going into four pack enclosures: LR 1PH & 3PH plus SR 1PH & 3PH

What’s 1PH and 3PH? Penthouse? “pH” is making Google search fruitless

 

[Zoomit]

What’s 1PH and 3PH? Penthouse? “pH” is making Google search fruitless

Phase. Different on board chargers—International packs have 3 phase AC charging capability; NA only has 1 phase

you could tell the difference because each consecutive brick is oriented upside down from the prior one IIRC.

I thought that was only on the S/X packs and Model 3 packs had all cells oriented the same way.

 

[darth_vad3r]

Phase. Different on board chargers—International packs have 3 phase AC charging capability; NA only has 1 phase

I thought that was only on the S/X packs and Model 3 packs had all cells oriented the same way.

Lol. I thought “phase” first, but was thinking DC-only and forgot about our EU friends and AC charging Each module has its own AC charger? Interesting that they would duplicate (quadruplicate) the AC to DC circuitry. Oh no wait. Pack. Hah. I misread. 3 module types in 4 pack types! Got it!

I may be misremembering a tear down pic of an S pack vs a 3. Unfortunately I’m pretty sure it was in the middle of some long tear down video I watched weeks ago so I probably won’t be able to find the source now

 

[GigaGrunt]

Technically that’s not “lower density” ... if the size of the SR bricks is smaller with less cells than the larger LR bricks with more cells, it can be the same density, just smaller size.

Based on photos/diagrams I’m guessing one zig-zaggy “row” (or column) got removed from the LR 46-cell brick pattern to make a shorter (narrower) 31-cell SR brick pattern. I would expect all of the SR’s module’s cells to be packed in the exact same way as LR with the cooling going through them all the same until you reach 31/46th the length of the module from the rear, and then filler material starts.

Really the cells would look identical from the rear til the filler material. It would only be the the plates connecting them in parallel in groups of 31 vs 46 that would be different (and electrical connections, etc) ... if you tore down an LR vs an SR to the point just the cells and goop were visible I doubt you could tell the difference* if you had a crop that showed only the first couple hundred cells in the module. Or the first 700-ish even. 744 cells in one SR module (31p x 24s).

EDIT:
*Ah no, wait ... you could tell the difference because each consecutive brick is oriented upside down from the prior one IIRC.

EDIT2:
Crappy ASCII art diagram... (only one 46-cell ‘+’ up top down view is ‘accurate’ (count is right), neighbouring ‘-‘ up not all depicted)...
+.+.+.+.-.-...
.+.+.+.-.-.-...
-.+.+.+.-.-...
.+.+.+.-.-.-...
+.+.+.+.-.-.-...
.+.+.+.-.-.-...
-.+.+.+.-.-.-...
.+.+.+.-.-.-...
+.+.+.+.-.-.-...
.+.+.+.-.-.-...
-.+.+.+.-.-...
.+.+.+.-.-.-...
+.+.+.+.-.-.-...
.+.+.+.-.-.-...

For a 31-cell brick pattern my guess would be:
+.+.-.-...
.+.+.-.-...
-.+.+.-.-...
.+.+.-.-...
+.+.+.-.-...
.+.+.-.-...
-.+.+.-.-...
.+.+.-.-...
+.+.+.-.-...
.+.+.-.-...
-.+.+.-.-...
.+.+.-.-...
+.+.+.-.-...
.+.+.-.-...

No.

 

[peakshaving]

No.

I've noticed that the EPA rating on the SR is different from the SR+. Are the two still sharing the same packs?

 

[Zoomit]

I've noticed that the EPA rating on the SR is different from the SR+. Are the two still sharing the same packs?

Of which EPA rating are you referring?

The early SR+ packs contained depopulated LR modules. Each brick had 15 dummy cells. Since then, they transitioned to dedicated SR/+ modules for the SR/+ packs. The SR cars have the same pack as SR+ cars and they have or will reduce their usable capacity via software.

 

[MP3Mike]

The early SR+ packs contained depopulated LR modules. Each brick had 15 dummy cells.

I think you are talking about the MR packs, not the SR+ packs...

 

[Zoomit]

I think you are talking about the MR packs, not the SR+ packs...

No, early SR+ modules would have 15 dummy cells per brick [46-31] and MR would have 9 dummy cells per brick [46-37]. Later SR+ packs had dedicated SR/+ modules per this comment: "Current modules for SR/SR+, MR, LR are same, cells removed. Future module design for SR/SR+ can run on any lines. Smaller, less dense bricks."

Ref: Model 3 SR+ and MR: No physical differences?

 

[darth_vad3r]

No.

Lol. Ok my next guess is a less narrow shape with some Tetris like overlaps of the bricks in series

 

[darth_vad3r]

No, early SR+ modules would have 15 dummy cells per brick [46-31] and MR would have 9 dummy cells per brick [46-37]. Later SR+ packs had dedicated SR/+ modules per this comment: "Current modules for SR/SR+, MR, LR are same, cells removed. Future module design for SR/SR+ can run on any lines. Smaller, less dense bricks."

Ref: Model 3 SR+ and MR: No physical differences?

Hmm. How do you make a “less dense” brick? More cooling space? More filler goop?

 

[Zoomit]

Hmm. How do you make a “less dense” brick? More cooling space? More filler goop?

I think he meant bricks with "fewer cells" in the new SR+ modules. Each 31-cell SR brick would be the same or similar density as 46-cell LR bricks.

 

[peakshaving]

Of which EPA rating are you referring?

The early SR+ packs contained depopulated LR modules. Each brick had 15 dummy cells. Since then, they transitioned to dedicated SR/+ modules for the SR/+ packs. The SR cars have the same pack as SR+ cars and they have or will reduce their usable capacity via software.

Gas Mileage of 2019 Tesla Model 3
The Model 3 SR is listed as 131MPGe while the SR+ gets 133MPGe. I would have expected the same ratings if the packs are the same unless this is because the software for the SR model consumes extra energy that it won't let the user use. I suppose that would sort of make sense since the EPA calculates these numbers based on amount of energy from the wall and not the pack...

 

[Zoomit]

Gas Mileage of 2019 Tesla Model 3
The Model 3 SR is listed as 131MPGe while the SR+ gets 133MPGe. I would have expected the same ratings if the packs are the same unless this is because the software for the SR model consumes extra energy that it won't let the user use. I suppose that would sort of make sense since the EPA calculates these numbers based on amount of energy from the wall and not the pack...

I would also expect the wall-to-wheel efficiency (MPGe) to be the same for both SR and SR+. The EPA has not yet published the application that includes the SR test data on their download site.* I think we'll need to see that to figure it out. It could come down to rounding error or just a different battery being tested. There's certainly variation battery to battery.

*Technically they did. In early Feb '18, it looks like Tesla submitted data for the SR, then decided they wanted to make the SR+ and resubmitted the same results but the car was now called Model 3 Standard Range Plus.

 

[willow_hiller]

No, early SR+ modules would have 15 dummy cells per brick [46-31] and MR would have 9 dummy cells per brick [46-37]. Later SR+ packs had dedicated SR/+ modules per this comment: "Current modules for SR/SR+, MR, LR are same, cells removed. Future module design for SR/SR+ can run on any lines. Smaller, less dense bricks."

Ref: Model 3 SR+ and MR: No physical differences?

Really interesting. Do we know if this has any meaningful effect on the performance of early SR+ Model 3s? Would it make them slightly heavier?

 

[darth_vad3r]

I think he meant bricks with "fewer cells" in the new SR+ modules. Each 31-cell SR brick would be the same or similar density as 46-cell LR bricks.

I dunno. They have more space in the module. Maybe they made a less dense brick design for better cooling?

He just said “no”, so we’re back to a battle of wits with a Sicilian ... where was I? Australia. LOL

 

[darth_vad3r]

I would also expect the wall-to-wheel efficiency (MPGe) to be the same for both SR and SR+. The EPA has not yet published the application that includes the SR test data on their download site.* I think we'll need to see that to figure it out. It could come down to rounding error or just a different battery being tested. There's certainly variation battery to battery.

*Technically they did. In early Feb '18, it looks like Tesla submitted data for the SR, then decided they wanted to make the SR+ and resubmitted the same results but the car was now called Model 3 Standard Range Plus.

Ya, I think they realized they were going to over deliver on range with the original design, but be crunched on margin, so instead they came up with the + idea to get better margins. Meanwhile they just upped the LR range for “free”