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Discussion Starter · #1 ·
These have become readily available now, just as predicted. 75 kwh packs are as cheap as $8000 on ebay. The only problem is those huge modules. Has anyone been able to break them up to functional units yet?
 

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Sadly, the supply of reasonably sized battery modules is dwindling. Brian's correct that it's impossible to resize the huge modules on a 3/Y and they do suck for integration in almost every car conversion.

Getting the cells extracted is a chore as well - soo much goop holding them in (the older modules are also a pain for extraction - an errant chisel/screwdriver will light a cell off while it's embedded with a few hundred others...don't ask how I know this). Just not worth the trouble unless you have nothing else to do with your time.

It's going to be even more fun with their upcoming "structural" battery and extracting their 4680 coke-can cells....
 

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Discussion Starter · #4 ·
(the older modules are also a pain for extraction - an errant chisel/screwdriver will light a cell off while it's embedded with a few hundred others...don't ask how I know this)
😅😅😅 Don't worry Remy- I won't ask!
 

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Discussion Starter · #5 ·
Thanks so much guys,- valuable information as usual... It's a bit disappointing, as the model 3/Y batteries are even more energy dense than the S/X. Used packs are also cheaper than the S/X ones.
 

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How long are those modules, exactly? I have been working on an s-10 where I pulled off the bed and built a flatbed to hide my batteries under. The space in mine is roughly 5 feet by 6 feet and 9.5" deep. If I had 75kwh I would estimate a range that was nearing 200 miles.
 

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Discussion Starter · #7 ·
How long are those modules, exactly? I have been working on an s-10 where I pulled off the bed and built a flatbed to hide my batteries under. The space in mine is roughly 5 feet by 6 feet and 9.5" deep. If I had 75kwh I would estimate a range that was nearing 200 miles.
From Jack Rickard's teardown; the two in the centre are 73 inches long and the two on either side of these are 67.5 inches long. They're all 11.5 inches wide and 3.5 inches thick.
 

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Hi Guys, interesting topic.


While these batteries are massive and mostly unsuitable for most cars Ive been thinking about either putting a model 3 battery under a van or more likely on the vans floor and building a fause floor above them. Wheel well positions may be the biggest issue with this plan depending on the van in question.
 

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... I have been working on an s-10 where I pulled off the bed and built a flatbed to hide my batteries under. The space in mine is roughly 5 feet by 6 feet and 9.5" deep.
My comment from another recent thread...
Four enormously long modules that won't fit in a vehicle being converted, unless someone wants to sacrifice the entire cargo area of a pickup truck, van, or station wagon.
:)
 

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From Jack Rickard's teardown; the two in the centre are 73 inches long and the two on either side of these are 67.5 inches long. They're all 11.5 inches wide and 3.5 inches thick.
With mounting space and housing that's something in excess of 46 inches wide (with all four side-by-side as in the Model 3 and Y)... too wide to fit between the wheel wells of compact pickups and some vans.
 

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Part of me wants to take exception to your claim that you have to sacrafice the cargo space, Brian; but then I remember the weight! In a small truck, I am guessing that a 75kwh pack would basically max out the rear weight capacity, so even if you build it into a flatbed, you would not be able to haul anything anyway. Still, it would be pretty cool to have a little extended cab pickup that could go 200 miles on a charge.
 

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Discussion Starter · #14 ·
This issue with the Tesla model 3 battery pack raises a question I've wanted to ask for for quite a while. Can't a whole tesla pack be fixed under the chassis similar to it's placement in production EVs? The space saving and low centre of gravity we could achieve if we did this would be fantastic. Has it ever been tried?
I believe there's enough space in most saloons (sedans), when the exhaust, petrol tank and drive shaft are gone. Cables could be routed to either side or fed through the tunnel. Ground clearance could be improved with spacers over the springs - may not even be needed if the conversion is an SUV. Does anyone think this is feasible?
 

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Can't a whole tesla pack be fixed under the chassis similar to it's placement in production EVs?
Sure, when the body is designed for it.

The space saving and low centre of gravity we could achieve if we did this would be fantastic
But the centre of mass of the rest of the vehicle would be raised by the amount that it would need to be lifted to accommodate the pack (and it will need to be raised). Almost anything running around on tip-toe so high that a pack will fit could be massively improved by just lowering it.

Has it ever been tried?
The closest that I have seen is Yabert's VW Westfalia, with a complete Chevrolet Bolt battery pack (mostly) under the floor. The van was already relatively tall, and the loss of ground clearance was acceptable in that case.

I believe there's enough space in most saloons (sedans), when the exhaust, petrol tank and drive shaft are gone. Cables could be routed to either side or fed through the tunnel. Ground clearance could be improved with spacers over the springs - may not even be needed if the conversion is an SUV. Does anyone think this is feasible?
But there isn't. There are lots of areas of floor or structure which are much lower than the top of the fuel tank or tunnels for exhaust or shafts. If you were shaping foam or a tank for liquid to fill all available spaces you could fit in a large volume; unfortunately, a battery pack is a rigid box, not a conformable material, so the lowest part drives the entire pack below that height.

Cars are just not made in a simplistic design that has a flat bottom with the fuel tank and muffler hanging under it so that when they are removed there is a nice available space.

Ground clearance could be improved with spacers over the springs - may not even be needed if the conversion is an SUV. Does anyone think this is feasible?
While Yabert didn't raise his VW, it is an unusual case, and even in that case he had to cut a substantial hole through the structure and the floor to accommodate the bump up at one end (under the rear seat in a Bolt) which contains small second layer of modules. Almost all production EV packs have a bump like that, either to fit more modules where more height is available (typically under the rear seat, but also under the front seat in the Leaf and some others); even Tesla packs which have a simple single layer of modules have a bump up to contain other components.

Packs have substantial thickness, so the suspension lift required to accommodate any of them is typically far too much to compensate with spring spacers.

No, I don't think this is feasible in most cases. There might be some ideal combination of a vehicle which already sits too high for no good reason other than style, a relatively flat pack, and a fortuitous alignment of the pack's bump with the space left empty by the fuel tank removal. A commercial van (such as a Ford Transit or Fiat Ducato / Ram ProMaster) with a high cargo floor and nothing under it might accommodate a pack, but the high area were it would fit is only rear of the cab area and that means it would need to be a long vehicle... and the pack which will fit will likely not be large enough for the heavy vehicle.

Most production EV designs are based on engine-driven vehicle models. The only ones which manage to fit a substantial battery pack in without major changes to the floor and structure are those which use the cargo space to carry at least a large portion of the battery, such as the Ford Focus EV:


You could do that. In fact, I had a 3 inch lift kit on my early 90's pickup truck that was strictly body spacers.
Now, triple that lift. And of course a body lift wouldn't work to fit a full pack from a typical EV because the pack wouldn't fit between the frame rails; it would need to be a suspension lift.
 

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Discussion Starter · #17 ·
Very relevant points Brian.
But I still think it's doable. Just humour me a bit - I might be on the verge of a "breakthrough" here...:)
Here's the underside of a Mercedes W220.
121179

121180

What we are looking for is just 2 or 3 spare inches of depth. Notice the downward protrusion of the exhaust pipes & the transmission. If we remove all those ICE bits as well as the heat shield and the black plastic aerodynamic cowling, we'll get a couple of inches at least.
The Tesla S/X packs have a couple of extra modules stacked at the front end, forming the bump. I think the 3/Y packs have the integrated charger & dc/dc parts in the packs' bump. I would suggest removing everything in the bump and putting them under the hood. Then custom reseal the pack. The thickness of the tesla pack without the bump would be about 4 -5 inches. if you've got even just 2 inches from stripping the ICE components from the car, you lose 3 inches of ground clearance a the most. 2-inch spacers over our springs and we in business yes? Merry Christmas everyone!
 

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...
Here's the underside of a Mercedes W220.
View attachment 121180
What we are looking for is just 2 or 3 spare inches of depth. Notice the downward protrusion of the exhaust pipes & the transmission. If we remove all those ICE bits as well as the heat shield and the black plastic aerodynamic cowling, we'll get a couple of inches at least.
... The thickness of the tesla pack without the bump would be about 4 -5 inches. if you've got even just 2 inches from stripping the ICE components from the car, you lose 3 inches of ground clearance a the most. 2-inch spacers over our springs and we in business yes?
Those places where the lift are supporting the car are structure - take off the aero covers and you gain perhaps a few millimetres, not inches. I also suggest measuring a Tesla pack... both the Model S/X modules and the Model 3/Y modules alone are 3.5" thick, so the pack will likely be far more than 4 inches. Then look at the clearance under the middle and take more than three inches away - I expect that you'll grind the battery pack into speed bumps.

Module design note: Although the Model 3/Y use cells which are longer (taller) than the Model S/X by 5 mm, the newer design interleaves both bus plates on the same side of the module, saving enough height to allow the modules to be the same overall height.​

Starting with a crossover/SUV style of vehicle and giving up the extra ground clearance of that style has more potential, but I'm sure that it's still not going to work well without radical floor surgery.
 

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Sure, when the body is designed for it.

Now, triple that lift. And of course a body lift wouldn't work to fit a full pack from a typical EV because the pack wouldn't fit between the frame rails; it would need to be a suspension lift.
It WOULD fit the modules if they were in a custom battery case that had the body mounts incorporated as hardpoints. And, no, it would not have to go between the rails, but on them.
 

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Discussion Starter · #20 ·
Those places where the lift are supporting the car are structure - take off the aero covers and you gain perhaps a few millimetres, not inches. I also suggest measuring a Tesla pack... both the Model S/X modules and the Model 3/Y modules alone are 3.5" thick, so the pack will likely be far more than 4 inches. Then look at the clearance under the middle and take more than three inches away - I expect that you'll grind the battery pack into speed bumps.

Starting with a crossover/SUV style of vehicle and giving up the extra ground clearance of that style has more potential, but I'm sure that it's still not going to work well without radical floor surgery.
I used to own a w220, but it was many years ago. I wish I'd spent more time under it back then... I'll have to check under one now, if I can get one to look at - and take a tape measure with me.
I've seriously considered using a Ford Expedition as a vehicle to convert. It comes with 9" of clearance. Is it an even crazier idea? It weighs 2.6 tonnes and has the cd of a brick... I like the idea though 😊
 
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