[electro wrks]

Here's a photo of one of the first applications of the new Tesla 4680 structural battery:

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.

 

[remy_martian]

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

 

[electro wrks]

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!

 

[electro wrks]

Yes, they corrugated the top - BFD

I believe the four squared-off corrugations are the front seat mounts and to add strength to the lower body in the event of side impacts

 

[remy_martian]

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?

 

[remy_martian]

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.

 

[john61ct]

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.

 

[electro wrks]

The car is going in the wring direction of repairability.

The cells in this design are probably permanently bonded in the battery box, with no convenient way of removing them without destroying them.

 

[electro wrks]

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.

 

[john61ct]

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

 

[remy_martian]

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.

You're being a bit overdramatic on your honeycombs.

Look at those rocker panels and the B pillar. They're comparable to any unibody. The car has to support itself on a lift when battery packs get R&R'd, and that includes dropping tye car to clear for other cars until a replacement pack shows up. It has to roll, it has to ride on a rollback without folding up.

To get the battery out, the seats and carpet have to drop with it. Ick.

The battery is self supporting, it takes seat loads to the rocker panels, and nothing more is required of it structurally.

Unlike the module-based batteries, however, if one of these cells lights off, the whole pack will incinerate itself.

And if you have a bad cell, the entire pack gets changed out. vs a module.

It's too much gee whiz brainstorming, without any repairability. This is where Tesla will have its lunch eaten.

 

[cricketo]

I like it when random individuals on the Internet are able to figure out where a multi-billion dollar company with hundreds of millions spent on R&D and the top engineering talent made a mistake

 

[remy_martian]

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

 

[cricketo]

The only thing worse than complete incompetence is the overconfidence.

 

[john61ct]

Not built for repairability.

Yes I can accept that as a given.

Yes that is evil from many POV.

But the way our system works, that is his call legally, a conscious design choice.

 

[cricketo]

a conscious design choice.

Exactly. Some people suggest design flaws, while in reality they are design optimizations from the viewpoint of the vendor.

 

[brian_]

To get the battery out, the seats and carpet have to drop with it. Ick.

Even worse, it will likely be necessary to remove the seats and anything else mounted to the floor disconnect wiring to the seats and other equipment, remove the mouldings around the edge of the carpet and then the carpet itself, and then drop the floor/pack while separating the weather seal between it and the rest of the body. I think that the assumption is that the original owner will never need to have this done, and subsequent owners don't matter.

 

[remy_martian]

Not built for repairability.

Yes I can accept that as a given.

Yes that is evil from many POV.

But the way our system works, that is his call legally, a conscious design choice.

That mentality works when you're the only game in town.

 

[john61ct]

If the market wanted longevity, Detroit could have built cars good for 100 years.

Tesla doesn't want many 2nd-hand Teslas out there

 

[electro wrks]

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.