SR & SR+ Battery Questions & Thoughts

[GigaGrunt]

I think all of the Model 3 pack variants have the same number of bricks. (They are wired in series, so they control the voltage of the pack.)

Also, the bricks aren't physically separate units, it is just how the cells are wired inside the module.

No. LR has two 23's (outer) and two 25's (inner). SR has four 24's. The number indicates how many bricks in module. Cells/brick determines density.

 

[GigaGrunt]

Lots. As I understand it, MR packs contain depopulated modules that are basically the same design as LR modules. SR packs have modules updated specifically for the reduced cell count and do not contain inert filler cells.

Correct.

 

[MP3Mike]

No. LR has two 23's (outer) and two 25's (inner). SR has four 24's. The number indicates how many bricks in module. Cells/brick determines density.

So every Model 3 pack has the same number of bricks, which is exactly what I said. (Sure they are allocated differently between modules, but that doesn't matter.)

The bricks aren't physically separate parts put together inside a module are they?

 

[GigaGrunt]

So every Model 3 pack has the same number of bricks, which is exactly what I said. (Sure they are allocated differently between modules, but that doesn't matter.)

The bricks aren't physically separate parts put together inside a module are they?

All cars have 4 tires, but doesn’t mean they perform the same....bricks are not physically separate.

 

[Zoomit]

Cells/brick determines density.

IIRC, it's 46 cells/brick for LR and 31 cells/brick for SR.

 

[Zoomit]

IIRC, it's 46 cells/brick for LR and 31 cells/brick for SR.

I need to run some more numbers, but there's a chance the SR batteries actually have 32 cells per brick.

 

[taraquin]

Does anyone know how much total and available energy the SR+-battery has? 55kW usable?

 

[Zoomit]

Does anyone know how much total and available energy the SR+-battery has? 55kW usable?

Slightly less. 155Ah at 350V = 54.25kWh. The EPA application shows 54.52kWh usable capacity.

 

[Zoomit]

LR has two sizes. Base is built the same for both, larger is inner but needs to be configured to a left or right, smaller is outer, needs to be configured for left or right. SR has one size, one base, configured to be inner or outer.

I stole and modified this graphic from electrek. It could be how the SR modules are configured. LR on top, my speculative SR on bottom.

 

[GigaGrunt]

I stole and modified this graphic from electrek. It could be how the SR modules are configured. LR on top, my speculative SR on bottom.

View attachment 406794

Are you asking?

 

[Zoomit]

Are you asking?

That’s how I’d do it, based on the constraints as I understand them. Is there a more optimal way to configure the modules?

 

[peakshaving]

That’s how I’d do it, based on the constraints as I understand them. Is there a more optimal way to configure the modules?

I would imagine the inner and outer modules would be mounted the same way for weight distribution reasons.

 

[Zoomit]

I would imagine the inner and outer modules would be mounted the same way for weight distribution reasons.

That very well may be how it is and I started off thinking they would do that but I think the way I have it minimizes the configuration change needed for each module. Counterintuitively, it also distributes the mass within pack enclosure more evenly, which I think would be better structurally and for crash safety. Just my speculation of course.

 

[GigaGrunt]

SR/+ pack has all 4 modules towards the rear, closest to the penthouse. Empty space filled by space filling device.

 

[Zoomit]

SR/+ pack has all 4 modules towards the rear, closest to the penthouse. Empty space filled by space filling device.

That I did not expect. That moves the SR CG back about 1% to a rear-biased 47:53. Here's an update graphic--ignore the previous one.

 

[Leafdriver333]

If I carry a dead body in the frunk would that make 50:50?

 

[Zoomit]

If I carry a dead body in the frunk would that make 50:50?

Said cargo must weigh 160 lbs, the spreadsheet shows. Going to be a tight fit, I'd say.

 

[willow_hiller]

Said cargo must weight 160 lbs, the spreadsheet shows. Going to be a tight fit, I'd say.

Sounds like you've got the next hot Tesla accessory in the works. 160 lb lead frunk weights.

Is the minor improvement in handling worth the moderate decrease in range?

 

[peakshaving]

SR/+ pack has all 4 modules towards the rear, closest to the penthouse. Empty space filled by space filling device.

I'm not gonna lie. I went ahead and knocked on the carpet to see if I could tell it was more hollow up front after reading this. I always wondered what the design was going to be for the SR packs ever since it was announced. Care to tell us what space filling device is made of?

 

[GigaGrunt]

I'm not gonna lie. I went ahead and knocked on the carpet to see if I could tell it was more hollow up front after reading this. I always wondered what the design was going to be for the SR packs ever since it was announced. Care to tell us what space filling device is made of?

Space filling material.