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4680 Tesla Battery Application

6K views 47 replies 8 participants last post by  brian_ 
#1 · (Edited)
Here's a photo of one of the first applications of the new Tesla 4680 structural battery:

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For comparison, behind the cut away mock-up is a mock-up of the old 2170 cell design.

This is from the Berlin Gigafactory public tour. It looks like the battery box completely replaces the floor and is bolted into the cast and sheet metal body. Corrugated cooling channels appear to be placed between every other row of cells. Not shown are the buss bars and the bonding between the top cover/ floor and the top of the cells. There's a lot of DIY potential here, with the right vehicle, with the bolt-in design and structural member aspect of the battery box.
 
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#2 ·
More Musk bullshit.

I was under the impression the cells were dropped into cavities in the gigacasting. These are still bolt-in batteries.

There's nothing structural about it, as compared to what they now use. I could probably drive the tractor over a Model S battery & not hurt it. Yes, they corrugated the top - BFD.

Thanks for the lookie
 
#3 · (Edited)
I don't think you recognize the extra strength and energy density advantage of having the cells packed tightly, and bonded together. The cell's cylindrical steel housings do double duty as a honeycomb like structure. When this honeycomb is bonded to the top and bottom of the battery box, this forms a very strong and material efficient honeycomb box and beam structure. Honeycomb designs are in the structures of many aircraft, spacecraft, and race cars where stiff, strong, and lightweight parts are needed.

So, maybe you could park 2 or 3 tractors on this battery box!
 
#5 ·
Mighty huge structural rocker panels, and B pillars coupling floor loads to the roof, on that spacecraft.

The car is going in the wring direction of repairability. That has been Tesla's achilles heel...a bunch of kids with no adult supervision. Who in the heck but Tesla puts door and hatch hinge bolts, used to adjust gaps, behind glued-in glass?
 
#6 ·
Yes, seat mounts - that's where most of passenger weight transfers to vehicle structure. You's think that aerospace honeycomb could handle it and that all that's needed is a corrugation to accomodate seat rail mounting screw length.

The battery likely handles its own structural weight, which a Tesla module does as well, but NFW does it add anything to the chassis for structural strength.
 
#9 · (Edited)
The battery likely handles its own structural weight, which a Tesla module does as well, but NFW does it add anything to the chassis for structural strength.
I guess we'll find out the first time somebody removes the battery box. I suspect a vehicle with this very strong and stiff honeycomb design battery box removed, will be a very weak and flexible structure indeed.
 
#7 ·
I reckon the main structural strength from a holographic 3D POV is the cast chassis spaceframe, handling torsion / tension the lot

creating the equivalent of rigid I-beams in the bottom plane surrounding all four of the pack-frame edges.

Therefore that frame together with the cells is simple rectangular prism / slab, acting as a floor alone

load-bearing the seats, passengers and other contents sitting on that floor

with of course a role to some extent locking in and supporting that frame at those four edges adding rigidity.

The honeycomb slab replacing trad crossbeams in that function.

That slab would be much LESS strong without the cells.

As opposed to a much heavier / cruder trad floor structure that would need to be just as strong with or without the modules is is designed to support

and whose load bearing capacity would be GREATER without them.
 
#10 ·
you mean without, right?

If so I agree

But everything heavy in the passenger space needs to come out too,

maybe replacing the pack means pulling the whole rest of the car up and away

either way bit of a moot issue, the car will never be going anywhere without its floorpan
 
#13 ·
I have three Teslas in the yard, and about 50 years f*cking around with building cars...started my first hotrod at 13. Worked for GM for three years. EE from a country where you do engineering for three years, then the EE stuff at the end and 35 hours a week was in class or labs....not this candy-ass 15 hours a week American crap.

Yeah...random.

Teslas are not designed for repairability. They didn't even put a seam in the rear quarter panel to be able to simply repair common fender benders.

To align the rear hatch or Falcon Wing doors, a 20 sec procedure on every other car on the planet, you have to remove the GLASS that's glued in.

The cars are easily totaled (which is good for salvage vultures like those of us here) because they are not designed for repair.

Another example...upper control arm replacement on the back of the X...the factory puts the pivot bolt in backwards, so you have to drop the DU to do a simple A arm change. Or cut the bolt off in tight quarters, risking a structural casting nick.

Bunch of unsupervised kids who get gold stars for doing stupid shit. No PR, no marketing, no repairability engineers with design veto powers like a normal car company has.

Yeah

Random
 
#20 ·
The cars are easily totaled (which is good for salvage vultures like those of us here) because they are not designed for repair.
This is an unfortunate trend with virtually all modern vehicles. From a DIYEV builder's POV, it is better if good reusable parts from vehicles like this become more readily available on the secondary market. The more vehicles that are totaled because of rich people and others freaking out about off body seams and a few dents, the more parts that we need are on the market. In the case of Tesla, that's top notch electronics, drive units, battery modules, and now potentially this excellent structural battery box.

I think that the assumption is that the original owner will never need to have this done, and subsequent owners don't matter.
It's quite inconceivable to me that Tesla would not make it reasonably easy to replace the battery box. Enough people are going to brick their batteries, or otherwise destroy them during the warranty period, to make this necessary. Removal is probably 1 to 2 hours of removing interior parts, mounting bolts, disconnecting plugs(like you write) and running a cut-out wire through the perimeter seal.
 
#23 ·
Some revolutionary aspects of this removable floor/structural pack come to mind. On the assembly line, the workers can stand in the open floor space to attach the head liner and most of the interior parts. This is a much more ergonomic and efficient way of attaching these parts. It involves much less crawling around on hands and knees to finish the interior. I'm impressed with the sliding center console. When I first saw the seat/ protruding console/ battery pack assembly, I thought they would need to tip it up in the front to install the assembly. Instead, the console slides back on rails temporarily and the assemble goes straight up. Nice detail.

If the full strength and stiffness of the honeycomb like structural battery pack in torsion, laterally, and longitudinally is utilized, the rest of the vehicle's structure could potentially be made lighter. The vehicle's structure could be optimized for crash and roll over protection.

If the pack is built in a honeycomb like structure, as advertised, the top and bottom covers will be heavily bonded to the top and bottom ends of the 4680 cells. Solvents and/or heat may be required to remove the covers. Let's hope the cells aren't damaged in the process. Monroe wants to sell the cells to OEM clients and the public (if they can afford it) for what- $800? a piece!
 
#27 ·
If the pack is built in a honeycomb like structure, as advertised, the top and bottom covers will be heavily bonded to the top and bottom ends of the 4680 cells. Solvents and/or heat may be required to remove the covers. Let's hope the cells aren't damaged in the process. Monroe wants to sell the cells to OEM clients and the public (if they can afford it) for what- $800? a piece!
As predicted, the cells are heavily bonded to the top and bottom covers:

 
#24 ·
Metal pack top and bottom can't be bonded to the cells or it'll be a 1s800p pack 😂 It has to be bonded to the honeycomb holding the cells.

Which begs the question of how the electrical connections are made and isolated and how they isolate the cells thermally, and how they cool them.

I'm interested in the pack guts, not seats and consoles which saves one or two robot ingress/egress cycles with an assembly.

Musk keeps INCREASING the price on his $35k car, and the $25k car is nowhere to be seen - I think someone stepped in some bovine excrement somewhere and now they're paying for "being German" (engineering things too complicated).

So.... grabbing 🍿🥤 for Friday.

ps Munro knows the Tesla fanboys are frothing at the mouth for this "advanced tech" cell, and a purchase order is a purchase order for the big dogs, so, yeah...$800 for a helluva vape pen battery.
 
#25 ·
There will have to be some kind of electrically isolating structure between the ends of the cells and the covers. My designer mind envisions a plastic grid that also holds the conductors, and has pins to keep the cells separated. It would have to be as open as possible to allow the maximum of bonding contact between the cells and the covers with an epoxy and/or intumescent glue. Musk says in a tweet, as I recall, that the design for the battery box was still evolving.

What does our resident crotchety burned-out old engineer and forum takeover artist think the design will look like? Meh meh meh meh...
 
#26 ·
I'm waiting to see what they did.

Having three Teslas here, I know how idiotic they are for serviceability & repair (who pulls glued in glass out to get at the door/hatch hinge bolts to adjust panel gaps, but Tesla?).

With no apparent adult supervision on Model S and Model X that I've seen, it means it's open season on approach, which I'm looking forward to seeing.

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Of course, nobody's modules are exactly serviceable at the cell level, so maybe I'm being a bit harsh at them killing modules altogether to where the pack vs a module has to be changed out if there's a cell fault.

Burn out, eh? Something tells me I need to be hurt and take that seriously.
 
#36 ·
...

Of course, nobody's modules are exactly serviceable at the cell level, so maybe I'm being a bit harsh at them killing modules altogether to where the pack vs a module has to be changed out if there's a cell fault.
Well except for the Mitsubishi iMiev modules. The pack cover is bolted together and sealed with a rubber gasket, the cells are bolted together and an individual cell can easily be extracted and replaced. It was absolutely designed to be servicable. The problem is there is no source for new cells from Yuasa or Mits (now owned by dunderhead Nissan who killed it off).
 
#31 · (Edited)
The still image shows the four terminal studs which are mentioned in the video. As the video says, this feature is the same as the original Model 3 / Model Y design, in which each of the four modules has a vertical stud protruding into the penthouse; the other terminal for each module is at the front. Those four modules are connected in series: the end terminals are the outer studs at the rear, the outer modules are linked to the inner modules at the front, and the inner modules are connected to each other by the studs. There is no need for anything except a connecting bar between those inner module studs, but I suppose there could be a service disconnect between them, since it is up in the penthouse. How all of the studs are connected is probably in SuperfastMatt's YouTube video about using the Model 3 modules and penthouse in a repackaged form in his Jaguar.

My guess is that the overall layout of the "structural" pack with 4680 cells is essentially the same as the original pack, but with the four groups of cells instead of separate modules. Of course many details have changed: larger cells, so fewer in each group, for a start... and of course it's all stuck together.
 
#33 ·
Also in this video is a discussion about, for lack of a better term, flaky info on battery energy densities and vehicle ranges. Tesla's claims in this area seem to be all over the place and maybe based more on economics and politics, than actual battery capacity. There might be, as discussed in the video, better battery performance through improved chemistry than was previously revealed.

We'll soon find out. If it is the case, it augurs well for the Semi and other vehicles that from the start seemed to have inflated range figures.
 
#34 · (Edited)
Still waiting for that dry chemistry-set they bought from Maxwell.

Musk is all about his stock options...no more, "go ahead and use my company's patents", lol.

Two years ago you were a fool for not buying a Tesla -- becuz autopilot can enable your Tesla to give paying taxi rides to hookers and vomiting college kids while you sleep. 😂

Grabbing a 🍿🥤 and watching the BS & truth unfold.

"structural battery" so far = "moar goo"...a cell repurposing disaster from the former Mr Green Mobility. If he wasn't in the battery selling business for Panasonic, he'd apply glue to the gigacasting honeycomb, only...
 
#35 ·
Looking at the latest Munro video where they pull the cell apart,



there is no way they can go to a pouch cell or a smaller diameter one - the dry coating has a large bend radius, which I think is the main reason for all the tabs....it's NOT thermal, as Elon has BS'd, but electrical continuity because of the dry coating cracking during rolling it up to put into the casing.

He tried making his own batteries, but Panasonic is now riding over the hill in a white hat to make this poopshow manufacturable.

Funny how the structural battery cheerleaders have gone silent. Damaging the gigacastings totals the car, cells are not easily extracted - that means insurance rates are going to get jacked up. Tesla anticipated this, and is offering its own insurance.

It's a cost reduction that lines Elon's pockets - if they can get it to yield functional cells, but could be darned expensive for owners of these abominations.
 
#37 ·
the worst part about these non-serviceable designs is it gives all the FUD people tons of ammo to attack EVs with

on other cars, you replace one module after then ten year mark or something, maybe more like 15, and the pack is fine

here ? a few bad batteries spoil the bunch and they're a BITCH to replace individually.
but tesla will happily sell you a whole new pack for $20k
"see??? you have to replace the whole pack every 10 years for 20k!!!" - fud people, probably
 
#38 ·
the worst part about these non-serviceable designs is it gives all the FUD people tons of ammo to attack EVs with
Yes, and some of those attacks are legitimate.

on other cars, you replace one module after then ten year mark or something, maybe more like 15, and the pack is fine
Unfortunately that's not true. Unless you are sorting through modules salvaged from scrapped EVs, the replacement modules would not come close to matching the old ones, and the replacement wouldn't make sense. Module replacement is for repair needed due to defects causing failures early in the pack life, or to allow the good modules to be salvaged from packs salvaged from vehicles (while the bad modules are recycled); I don't see it as rational for pack life extension at least at the OEM's service operation or dealership level.

here ? a few bad batteries spoil the bunch and they're a BITCH to replace individually.
I assume that you meant "a few bad cells". No, they're not just difficult to replace, they are effectively not replaceable. Enough bad cells to make the pack performance unacceptable means scrapping (and hopefully recycling) the entire battery (pack).

but tesla will happily sell you a whole new pack for $20k
"see??? you have to replace the whole pack every 10 years for 20k!!!" - fud people, probably
Replacing the entire battery (pack) every 10 years - or hopefully longer - for something vaguely like $20K is not FUD, it's reality for cell-to-pack designs that are glued and welded together.
 
#40 ·
The cylindrical cell battery pack(and more specifically with 4680 cells) seems to be such a bad design, as some of the naysayers on this thread have tried to beat into our heads, that more and more car builders are planning to switch to them, according to some reports:

https://cleantechnica.com/2023/01/28/gm-switching-to-cylindrical-battery-cells/

Could this be a collective OEM vehicle maker suicide? Is the tired, uniformed, unimaginative logic of the naysayers to be believed?

Or maybe, like many of us here along with the OEMs, we have seen the seen the true advantage of using these cells. I suspect switching to some form of giga-castings and structural battery packs are next with these OEMs.

Look, it's unfortunate that these new designs probably cannot be easily broken down into smaller battery groups that are more useful for typical DIY projects. I for one welcome the challenge of finding good uses for reused battery packs and their vehicles. I believe they are going to be a great resource for people with creative and imaginative minds in the DIY and vehicle conversion communities. Let's get to work.
 
#41 · (Edited)
Grab a sheet of paper. Draw a small square. Now draw a circle that tangentially touches the square's sides.

Show me the lack of empty space when using a circle to occupy SQUARE inches/cm.

Now, do the same for as big a square as you can draw on the paper.

Do you have more or less empty space?

You can argue for HCP, but there's still empty space.

GM blindly copied Tesla's bootstrap business model, building 4.5 ton monstrosities and Caddy Lyriqs. Each sold a few dozen units last quarter. They can't keep Bolt EV on a dealer lot -- they sell out before delivery.

So, yeah...4680 will fix stupid...or is it more lemming stupidity?
 
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