They do kinda look like hose fittings, but I am not convinced they are. I also don't think that picture shows final design and at Battery Day they pointed out that the tabless design allows the cells to be cooled by the bottom and that this allowed denser packing.
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4680 batteries, what is the advantage?
- Thread starter MontyFloyd
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JRP3
Hyperactive Member
There isn't anything else they could be. Those are side coolant ribbons with hose fittings on the end. Maybe it's not the final design but it would be odd to bother adding them in the most recent mock up, could have just left them out if they weren't sure.
SummerlinChiro
Member
Advantages of the 4680 battery fall into two categories; production and vehicular use.
The #1 production benefit is the dry electrode process. It is hard to overstate how much better this is over making a slurry with solvents, then having to dry the electrode material and recover the solvents. The dry electrode process which Tesla acquired when they bought Maxwell Technologies is the primary reason why the 4680 production uses 1/10th the area compared to wet electrode battery production.
The other production advantage of the 4680 is the "tabless" design, without that tab in the way the automation process is faster and easier.
The continuous tab design is key to improved vehicular performance as well. The longer and narrower current path through that tiny tab limited the size of the cell. The 4680 continuous tab design can handle the current of a larger cell, and has a better thermal heat dissipation path for the inside layers of the jellroll, as well as generating less heat due to that shorter and wider current path.
Here you can see even though the 4680 has only 5x the energy, it can generate 6x the power.
That's a 20% increase in power for the same capacity. This bodes well for for increase performance overall, or at least better performance as lower states of charge.
I hope and expect that Tesla will increase the energy storage for the Model 3 and Model Y by about 10%, to about a 88-90 KWh capacity pack. This means we could easily have a 4680 3 or Y Performance model with 600 HP.
The larger battery reduces part count and allows using the can as a structural member leading to further weight savings.
Both the production methods and cell-to-structural-pack nature of the design lead to significant cost savings. I expect 4680 continuous tab designs to emerge a clear winner in the future.
Keep in mind that as they continue to make dry electrode process production gains you can expect to see this form factor with various chemistries like LiFePo, higher silicon, and someday solid state.
The #1 production benefit is the dry electrode process. It is hard to overstate how much better this is over making a slurry with solvents, then having to dry the electrode material and recover the solvents. The dry electrode process which Tesla acquired when they bought Maxwell Technologies is the primary reason why the 4680 production uses 1/10th the area compared to wet electrode battery production.
The other production advantage of the 4680 is the "tabless" design, without that tab in the way the automation process is faster and easier.
The continuous tab design is key to improved vehicular performance as well. The longer and narrower current path through that tiny tab limited the size of the cell. The 4680 continuous tab design can handle the current of a larger cell, and has a better thermal heat dissipation path for the inside layers of the jellroll, as well as generating less heat due to that shorter and wider current path.
Here you can see even though the 4680 has only 5x the energy, it can generate 6x the power.
That's a 20% increase in power for the same capacity. This bodes well for for increase performance overall, or at least better performance as lower states of charge.
I hope and expect that Tesla will increase the energy storage for the Model 3 and Model Y by about 10%, to about a 88-90 KWh capacity pack. This means we could easily have a 4680 3 or Y Performance model with 600 HP.
The larger battery reduces part count and allows using the can as a structural member leading to further weight savings.
Both the production methods and cell-to-structural-pack nature of the design lead to significant cost savings. I expect 4680 continuous tab designs to emerge a clear winner in the future.
Keep in mind that as they continue to make dry electrode process production gains you can expect to see this form factor with various chemistries like LiFePo, higher silicon, and someday solid state.
That, that is less obvious info, how much easier, less resource consuming, it is to make LiFePO (LFP) components than other formulas.
Easy to see the ingredients are readily available.
Question:
Size/volume aside, is there any other advantage to using LFP in 4680 over 2170?
SummerlinChiro
Member
Assuming they can do the dry process (which they implied yes at battery day), then all the production advantages apply.
One thing I didn't mention is the reduced waste vs prismatic cells. Every video I have seen of prismatic cell production shows stacking and trimming of the layers, none of that with the jelly roll design.
The higher power output, lower flammability, lower cost, lower internal resistance, and longer cycle life of the LFP just carry over to the 4680 form factor.
The guy who is pretty good on battery tech is Jordan Giesige, his channel is called The Limiting Factor
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JRP3
Hyperactive Member
Dry electrode process should be applicable to any form factor, I don't see any reason it couldn't be used for prismatic or pouch cells, which allow for greater volumetric density.
Was asking if the gain is linear with size, or if there was exponential gain (sounds like its linear)
Will check vid.
Yes, take Rivian for example. Oh wait.
He must of slept through the battery day event.
I'll be honest. This so called structural battery pack terminology kind of gives me the creeps. How on earth are they planning on conducting battery swaps if there would be any battery warranty issues? What are they going to do, write off the car?
JRP3
Hyperactive Member
They obviously think battery pack failures will be exceedingly rare. Most pack "failures" were not cell related but electronics related, such as the high voltage contactors. I expect they'll be accessible without removing the pack. I'd also expect the structural pack can be removed from the front and rear casting members the same way it was installed.
I you look at pictures of the new chassis, it has no floorpan. It is a freestanding structure independent of the battery pack.
The pack adds rigidity and structural integrity to the chassis, but how it is integrated I haven't seen.
If it's bolted in place, which seems likely, then it's serviceability isn't in question.
If it's bonded in place, then either they think it will never be a problem, or they're willing to write-off the chassis after an 'event'.
I find the latter scenario to be unlikely.
Terminator857
Active Member
The 4680 revolution: From battery day: 4680 battery tech offers 56% cost reduction and 54% range increase (energy density increase). This has the potential to revolutionize the world in many ways.
From battery day:
14:27 into the video.
- Form factor improvement allows for 16% improvement in range. 14% improvement in dollar per kWh.
- Manufacturing improvements: 18% improvement in dollar per kWh.
- Anode, silicon: stores more lithium than graphite: Cost: $1.20 per kWh. This allows for 20% range improvement. 5% reduction in $ / kWh.
- Cathode: nickel: 15% reduction in cost per kWh. 1/3rd Manganese.
- Optimize the nickel enrichment process for cost savings. 66% cost reduction in capex cost. 76% cost reduction in processing. Tesla building it own cathode processing plant.
- Lithium enrichment: Sulfate free process: 33% reduction in lithium cost.
- Total cathode and anode savings results in a 12% reduction in costs at the batty pack level.
- Structural battery pack savings: 7%. 14% range increase.
- Total savings: 56% = 14% + 18% + 5% + 12% + 7%
- Range increase: 54% = 16% + 20% + 4% + 14%
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Good. At that time, the model 3 LR had about 325 miles EPA range. A 54% increase would yield 500 miles. Can't wait!
Don't get too worked up about range increases. Tesla has no incentive to give away range.
The 4680 battery remains in limited availability, and there's no competition offering similar range that can be delivered in any volume.
Also, Tesla has massive order backlogs. Are they gonna give everyone more range? Won't people just cancel and re-order if they didn't?
Also, there's never been any discussion about updating the M3 to accept 4680 batteries. That requires a new battery pack design and chassis changes.
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SummerlinChiro
Member
You are adding up the wrong things
Savings are not 56%
Range increase is not 54%
Terminator857
Active Member
You are wrong, this is just what tesla has stated in their presentation. See 14:27 into the referenced video.
Guys, you can't directly translate Battery Day presentations to real-world range.
There are a host of other variables. The new weight of the vehicle, for starters.
And de-populated battery packs, for another - they'll put in inert cells to manage range and resources.
Tesla won't be giving away range when batteries are precious and no competition can deliver cars in quantity.
Just chill for a couple weeks. We'll all find out the final answers very soon.
So I suggest you wait for the final specs from Tesla and the EPA on the new MY configurations.
Terminator857
Active Member
Just chill. Post wasn't about Model Y. Was about improvements that 4680 tech offers, directly quoting from Tesla battery day. There is no date specified by Tesla when the tech will arrive.
Why are you trying to distort posts and insinuate it is about something else?
Because the thread is going deep on speculation.
Battery Day is cited for all manner of wishful thinking, unattached to reality.
Why are you assuming Battery Day was not grounded in reality? Do you think Tesla was making up the numbers they presented in Battery Day? If so, what is your evidence for this? Because such an assumption would not be in keeping historically with Tesla's presentations of the past.
In part because the way the numbers were presented appeared to be deliberately over-optimistic and misleading.Why are you assuming Battery Day was not grounded in reality? Do you think Tesla was making up the numbers they presented in Battery Day? If so, what is your evidence for this? Because such an assumption would not be in keeping historically with Tesla's presentations of the past.
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