Tesla Model 3 Battery Secrets Revealed: Video


A look at the inside of the modules and the cells.

We’ve seen the battery pack of the Tesla Model 3 torn open and disassembled before. Then, as now, EVTV delved into its internals to share the what was found. This time, though, the outfit opens up an individual module, and even a 2170 cell, for all the world to see. The observations made by host Jack Rickard are illuminating.

Inspecting the module, he notes that each end has a “manifold.” They basically feed coolant through the many channels of the aluminum ribbons that snake through each row of cells. Packed in all the open spaces of the design is a light blueish material described as “crumbly and soft.” It had been speculated that this substance is a fire retardant — that theory doesn’t appear to be tested here with open flame — but Rickard believes its just added to make the internals of the pack more “robust and resilient to damage.”

Each section of the module holds 46 cells. Each 2170 cell appears to be held in place by a JB Weld-like adhesive. Our host informs us they could only remove it using a grinder fitted with a wire wheel.

Discussing the energy storage capabilities and admitting the numbers are kind of “squishy,” Rickard believes the 235-Ah module holds about 220 Ah of usable energy. He puts the cell capacity at 4.8 Ah. He will be doing some further capacity testing, though believes his estimate is reasonably accurate.

From here, the video turns its attention to the insides of the cells. With the outside cannister removed, Rickard unrolls an example of the 2170 cell. Unfurled, the anode, cathode, and separator layers of the Model 3 2170 cell measure about about 34 inches (86.36 centimeters).

He later presents materials from that cell and that of a 18650 cell from a Model S pack attached to a whiteboard and talks at some length about them. According to Rickard, the actual energy storage abilities of the cells isn’t that different per kilogram. He puts the Model S 21650 cell at 240 Wh/kg, while the new Model 3 cells he pegs at 247 Wh/kg.

While the improvement seems rather slight, he does note that if you include the other materials that make up the entire pack, the energy slab beneath the Model 3 holds a more significant amount of energy per unit of weight than Model S: 159.5 Wh/kg to 126.7 Wh/kg. Considering the Model 3 pack also holds a number of components, the improvement is actually quite impressive.

While the entire video may be more than most will find compelling, there are enough interesting points that arise that hardcore electric vehicle enthusiasts may want to watch all the footage. For instance, if you’re planning on pulling apart your own Model 3 battery pack, they discuss some of the new fasteners used to attach the upper section of the pack. Enjoy!

Source: YouTube

Categories: Tesla, Videos

Tags: ,

Leave a Reply

30 Comments on "Tesla Model 3 Battery Secrets Revealed: Video"

newest oldest most voted

Jack marvels at how Tesla got the pack (all in) density up to 159.5wh/kg in the model 3, vs 126.7 wh/kg in the Model S. Yet makes no mention of how the Model S pack was carrying a significant portion of the car structure inside the pack. The Model 3 shifts this structure (and associated weight) to the “body in white”(sort of an “exoskeleton”) .

Am I in error to point this out? Was the model S pack (all in) weighed without the “endoskeleton”?

From what I understand, a Model S & 3 car contains a number of battery packs.
I don’t think the pack level means all the battery in a given car.
So they would have been comparing the same battery function of model 3 and S.
And Surely I don’t think they would make this newbie mistake in such an important metric.

I dunno about the Wh/kg* rating, but the Model S battery pack originally weighed between 1200-1300 lbs, casing included.

*Where it stands for Watt, “W” is always, always capitalized. #GrammarNazi

It’s odd that they’d describe it as J-B Weld, instead of calling it epoxy. I suppose a person could test it by putting it through various solvents (e.g.: acetone) to see if it dissolves it. The blue stuff looks like it could be some sort of silicone, but it’s hard to tell from photos.

21650 –> 18650 ?

Yes, it’s odd to see such an obvious error in info from someone who claims to know more than the rest of us about Tesla battery packs.

Calls into question everything he says, doesn’t it?

“Calls into question everything he says, doesn’t it?”

No, it doesn’t.

I imagine Jack has forgotten more about electronics, computers, solar,and EVs than you or I will ever know. But that doesn’t mean he never mis-speaks, or is mistake free. If you’re actually going to do something, you can’t be afraid to make some mistakes.

Jack isn’t perfect, .. but he does get a lot done.

Yep, if you watch this video, you know this guy knows what he’s talking about… probably the best video on Youtube on this battery… separates the Referral Hounds from people that actually work to create great content. I don’t see Ben Sullins doing anything like this.


Just yesterday, you said that FCEVs “burn” hydrogen or other fuel? That’s an obvious error in info from someone who claims to know more than the foolcell fanboys about hydrogen fuel cells.

Calls into question EVERYTHING you say about hydrogen fuel cells, doesn’t it?


On the cooling:

Tesla went to great lengths to move heat from every every one of those small cells. What a stark contrast to the Nissan approach of just sealing the entire battery pack up in an airtight box –“thermal management be damned”.

Yeah, I”m surprised to see in the photo above that the cooling ribbon runs very nearly the entire height of the cell, from top to bottom. I think that is a lot more conductive surface area per cell than the much narrower ribbons used in the Model S/X packs!

I no longer wonder how Tesla managed such a significant improvement in heat transfer with the Model 3 battery pack cooling system.

The blue goo:

So, that is just packaging? A shock absorber to help prevent damage/failure in the cooling and electrical circuits? (damage from vibrations, expansion/contraction)

/add,Between the blue goo and the “jb weld” — doesn’t look like you could go in and replace/repair much of anything inside one of these modules. Also, does not look like an easy process to recycle.

‘Fire retardant’ qualities also designed in perhaps? (as one of the X number of attributes).

Recycling was always going to be an industrial process of putting the modules through a giant grinder that pulverized the pack to tiny pieces, separating out the valuable metals, and doing something or other with the rest.

Admittedly I don’t know a lot about recycling, … but I’m pretty sure they’re not going to drop the whole (still fully assembled) module in a grinder.

I believe they are. Tesla has yet to confirm exactly the specifics. In fact, I think the industry as a whole has recently started to gravitate toward this. Will see if I can produce a link on how the approach is more economical.

I’m know they grind , … but I assumed they surely separate the cells out first ,.. I dunno.

No point. The cells can’t be reused or remanufactured. The guts inside have degraded, so the best you can do is mash it all together and extract out the useful stuff. The rest, the fluff, gets mashed together and made into plastic bricks, or carpet pads, or whatever. To be efficient, industrial processes are bulk processes.

Yes, but after they manualy separate major assembly component.

At least, some process do it this way.


Actually , to M Hovis’ point. That video does show the modules going in whole.

They do the grinding thing with Lead Acid Batteries.

I think the potential for sound deadening is being ignored. The “blue goo” may serve more than one purpose, which would be typical for Tesla’s approach to building cars.

I could see that. Might be some noise associated with all the plumbing that’s best left out of the cabin.

Just from the pics, I’d say the soft blue goo is a type of thermal interface material, e.g. Berquist GF3500.

It helps ensure uniform temp across the cells.

Well there you go. Thanks.
“Thermal Interface Materials (TIMs) are a category of products used to aid thermal conduction between mechanically mated surfaces, such as a semiconductor device and a heat sink. While the surfaces to be placed in contact may appear flat, closer inspection will show imperfections such as tool marks, warped or imperfectly-flat surfaces, surface porosity, etc. that prevent actual physical contact between the two surfaces over much of their mating surface area, making the thermal resistance of the mechanical interface a lot higher than might be expected based on the apparent area of contact.

The purpose of a thermal interface material is to fill gaps between mating surfaces with a substance that’s got better thermal conductivity than the air that would typically fill those gaps otherwise, in order to improve heat transfer between the two surfaces. The difference can be significant, as typical TIMs conduct heat roughly 100 times better than the air they displace. A variety of products adapted for different use cases are available, and the purpose of this page is to provide an overview of available options and inform the process of choosing and using a TIM.”

Wouldn’t something like that be too expensive?

The gray “JB Weld” stuff is a thermal structural adhesive used instead if a gap pad to make contact between cells and the cooling system. Its also a dielectric.

Blue stuff is multi purpose. It supports the wire bonds mechanically, provides creepage isolation, helps with propagation, and may also be a desiccant.

Energy density by volume is more important than energy density by weight for EVs. It’s been proven that adding more capacity overshadows addition of extra weight (considering current relative lithium ion density). So stuffing in more batteries is more important now than making them lighter.

I was aware the pack was made like that, nothing really news except some details.
What I got from the video is that energy density gains at cell level are small, pack construction is good with great thermal management but also very complex and probably costly.

I’m amazed by that roof of solar panels.
And he’s still got two more large roof area’s to cover.
$$$PROFIT$$$ – Money for Nothing, that’s the way to do it.