Tesla Model 3 battery teardown!

jonescg

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[youtube]CpCrkO1x-Qo[/youtube]

The guys at Autoline Network have put a Tubecast together of the Model 3 teardown where they discuss the BMS, onboard controls, and of course, the battery :twisted:

The cooling system was always going to be an engineering challenge, given their desire to pack as many cells into the space available. So they used thermally conductive silicone gloop to both stabilise the cells from vibration and to soak heat away from the cells towards a cooling plate top and bottom.

The wire-bonded busbars are consistent with their earlier battery designs, although a huge weight saving has been realised in not using the polycarbonate supporting plates.

Model 3 battery1.JPG

Model 3 battery2.JPG

Model 3 battery3.JPG

Model 3 battery4.JPG

Model 3 battery5.JPG

I don't think they will be stopping the cells from getting very hot on occasion, but they will definitely work at getting the average cell temperature down. I look forward to more in-depth teardown!
 
Gawd...I love Tesla but who would sit here listening to 4 guys sitting and talking for over an hour.

Anywho, I'm hoping in the near future to pre-order my model 3. I'll be getting the standard battery and essentially bare bones model...$36000 is quite a stretch for my family right now and the foreseeable future. However I am driving around a 9 year old car so I'll be needing something in the next year or so....
 
Save yourself the pain and skip to 29 mins. Or just open the files I posted for stills.
 
Philaphlous said:
Gawd...I love Tesla but who would sit here listening to 4 guys sitting and talking for over an hour.
So much of what's really popular on youtube these days (at least for more moderately intelligent people) are youtube videos on just critical thought and ideas on the world. Like Sargon of Akkad channel with nearly 1million subscribers. https://www.youtube.com/user/SargonofAkkad100/videos
Just for this guy alone, there is something new to listen to every day. I been looking forward to seeing what new "internet only" media will bring us and so far I think this kind of stuff is the best stuff for casually replacing listening to the radio while ur in the car etc.

But there isn't anything really to "see" on these critical thought videos that are so popular, I almost always just listen to them like a podcast while driving or walking, the YT platform is just so convenient and easy to use for this kind of stuff now, especially if you got a large data plan for your phone. What I am saying is, while it's on Youtube, it goes without saying that they expect you to just listen to it for the most part and not watch it.

https://youtu.be/QZrqi7MEuQA
[youtube]QZrqi7MEuQA[/youtube]
 
Am I the only person here who is interested in the battery? :/
 
The battery is not exactly anything new ..is it ?
Its cells, the configuration, construction, capacity, etc etc have all been discussed before.
In that video, they did not seem to understand it too well anyway, refering to "whiskers" or contactors when we know they are the fusible links. And certainly estimated the cell capacity wrong at 6Ah, when its been stated by other reliable reports at 5Ah
 
The battery is massively different to the Model S/X battery.

Radial cooling by means of a long cooling channel has been abandoned in favour of axial cooling via the thermally conductive silicone goo.
All the cells are in the same orientation (not inverted) so they can terminate the pack on one side only (easier on assembly).
The four modules are effectively one large non-servicible part. Any errors at assembly mean the whole thing is wasted.
The tolerances between cells are so small that robotic assembly relies on sub mm precision.

It's a big step into the unknown; everyone else is using modular packs with more convenient features...
 
That new cheaper thermal management method of the Tesla 3 seems to affect the range of the car considerably.

This guy driving his new Tesla Model 3 in Canada while wearing full snow gear so he doesn't use the heater at all to keep warm and ruin his range, fully admitted that the range he was getting on the Tesla 3 was more than half of the claimed range of the car. This was due to the cold affecting the battery performance.

This guy runs also Facebook blog and Twitter blog but he never, ever, admitted/mentioned this serious issue this on his blogs. This just goes to show how hardcore everyone is on loving Tesla and not being critical when being critical is due.

https://youtu.be/49WftO5L71I?t=1m47s
 
I'd say the thermal management is probably OK for cold climates, but might not be good enough for hot climates. We shall see when they come to Perth.

And everybody knows that EVs lose range in the cold - Tesla themselves say so on their owners manuals. That's why having 300 km + of range to start with is a good thing. I wouldn't have considered it a defect or anything slight.
 
jonescg said:
The battery is massively different to the Model S/X battery.

Radial cooling by means of a long cooling channel has been abandoned in favour of axial cooling via the thermally conductive silicone goo.
All the cells are in the same orientation (not inverted) so they can terminate the pack on one side only (easier on assembly).
The four modules are effectively one large non-servicible part. Any errors at assembly mean the whole thing is wasted.
The tolerances between cells are so small that robotic assembly relies on sub mm precision.

It's a big step into the unknown; everyone else is using modular packs with more convenient features...

These are your thoughts or they are talking about them in this video? I mean if they do not talked about it, the video is useless and only usable things are the photos of uncovered battery.
 
So glad to see potting and single ended interconnects in a Tesla.

Massive step ahead of Model S pack in packaging density and ruggedness.

I also wouldn't judge the performance of the heat path without understanding it's cooling system.
 
@Pajda - just my thoughts and observations. I know that earlier reports suggested a radial cooling approach where the cells were glued to the micro channel extrusions, but they aren't obvious from this video. Also, it's hard to see where the coolant enters and exits the battery pack other than the big tubes on the top of the modules. I'd love to see more tear down for sure.

@Luke - The thermally conductive material for potting is a big improvement for sure. The temperature differential form one side of the cell to the other (cooled versus not cooled) could be quite significant under hard use. But the encapsulant should ensure it's more even. It should live a long life - but then again, it's permanent, so it better! :lol: And yeah, until we see the rest of the battery innards it's pure speculation on my part. Cause it sure isn't clear from what we see here.
 
jonescg said:
@Pajda - just my thoughts and observations. I know that earlier reports suggested a radial cooling approach where the cells were glued to the micro channel extrusions, but they aren't obvious from this video. Also, it's hard to see where the coolant enters and exits the battery pack other than the big tubes on the top of the modules. I'd love to see more tear down for sure.

@Luke - The thermally conductive material for potting is a big improvement for sure. The temperature differential form one side of the cell to the other (cooled versus not cooled) could be quite significant under hard use. But the encapsulant should ensure it's more even. It should live a long life - but then again, it's permanent, so it better! :lol: And yeah, until we see the rest of the battery innards it's pure speculation on my part. Cause it sure isn't clear from what we see here.

IMHO, the potting is for vibe and corrosion resistance, and the majority heat path is likely through the bottom of the cell.
 
TheBeastie said:
This just goes to show how hardcore everyone is on loving Tesla and not being critical when being critical is due.

Yeah we all know batteries are affected by cold but I still don't get this either, how can loosing close to half your range because you drive in cold climates be acceptable to so many people?
 
mistercrash said:
Yeah we all know batteries are affected by cold but I still don't get this either, how can loosing close to half your range because you drive in cold climates be acceptable to so many people?
Because -

1) When you need 100 miles of range max, losing half of a 300 mile range is no big deal

2) When there's still a way to get that 300 miles of range when you really need it, it's even less of a big deal.
 
mistercrash said:
TheBeastie said:
This just goes to show how hardcore everyone is on loving Tesla and not being critical when being critical is due.

Yeah we all know batteries are affected by cold but I still don't get this either, how can loosing close to half your range because you drive in cold climates be acceptable to so many people?
Its not acceptable, most of the time when I comment on things like this I still do it with the mind frame of what the widest group of people probably see it.
Most people would get their opinion of a Tesla from some EV fan or mainstream-media where its crucial to be as supportive/positive as possible to be as profitable/have most viewership as possible, people hate being told the truth, just try arguing with someone on twitter about lithium battery can cause fires below a Tesla crash/fire-news-tweet, they will viciously tweet directly to you for the next week telling you how lithium doesn't burn at all, period. These types of people who would rather believe lithium doesn't burn are very very important viewership to mainstream media and they will focus on keeping them happy, when ever possible.

If someone did a survey on the street with every-day people and asked the question "Does a Tesla range increase when used in the extreme cold?"
I am willing to bet that 99% of people would choose "yes, Tesla's range is extended in cold climates"
Mainstream-media in its current form of abusing its power by having its own dedicated spectrum is just cancer on modern society.
 
Note the insulating dividers between banks of parallel cells . The cells in parallel are ok if they do touch. Banks in serries cannot touch

Contractors at the gigafactory went to the media yelling hysterical about defective model 3 battery packs. The media pays cash on the down low if you have any negative Tesla rumours. "Wall Street" pays the media on the down low to spin the narrative

--------
Two current engineers told CNBC that they are concerned some of the batteries being shipped do not have the minimum gap required between lithium-ion cells. These engineers warned that this "touching cells" flaw could cause batteries to short out or, in worse cases, catch fire.

These engineers said they raised the issue internally, but their concerns were shrugged off by managers.

A Tesla spokesperson dismissed these comments as "false claims," and strenuously denied the company is shipping hazardous batteries.

"The implication that Tesla would ever deliver a car with a hazardous battery is absolutely inaccurate, contrary to all evidence, and detached from reality," the spokesperson wrote in an email to CNBC.
 
Re: the media - yes the focus on 'balance' is the source of this. Everybody can see how successful Tesla has been in the grand scheme of things, so rather than leave it as is, reporters and commentators will double down on the criticism and scrutiny...

I think the inter-cell insulation is no doubt fine, but I was thinking the cell top wire-bonding would be the challenge. The whole pack looks rather like... an e-bike battery pack :shock: .
 
The precision/accuracy of 30 year old cnc wirebonding machine tech is more than enough for large cells. Today's machines are way overkill


Simply use thermal camera with machine vision to flag bad "welds". Load test before encapsulation

You can think of the bus bar layer as a flex pcb but instead of kapton it uses silicone with the highest heat transfer for the allowed viscosity (injection flow rate
 
billvon said:
mistercrash said:
Yeah we all know batteries are affected by cold but I still don't get this either, how can loosing close to half your range because you drive in cold climates be acceptable to so many people?
Because -

1) When you need 100 miles of range max, losing half of a 300 mile range is no big deal

2) When there's still a way to get that 300 miles of range when you really need it, it's even less of a big deal.

You pay for the electricity to fully recharge the battery that should give 300 km of range, but if it's too cold outside, you will only get 170 km range (as an example) for the the amount of power you put in? But it's ok because you only need a range of 100 km for your commute or you can just pay for more electricity to fully recharge again to get a max of 170 km range because it's cold out? Or only use the car on warmer days?
Seems to me that every EV on the market is expensive and will work well depending on where you use them. Can't be too hot or too cold outside. I still drive an ICE car because I live in Canada and a full tank of gas will give me the same amount of range whether it's really hot or really cold or anywhere in between.
I really wish I could have an electric vehicle to replace the ICE one I use, but I can't move down South far enough for it to work well all year round.
 
mistercrash said:
You pay for the electricity to fully recharge the battery that should give 300 km of range, but if it's too cold outside, you will only get 170 km range (as an example) for the the amount of power you put in? But it's ok because you only need a range of 100 km for your commute or you can just pay for more electricity to fully recharge again to get a max of 170 km range because it's cold out? Or only use the car on warmer days?
It is OK if you get slightly less range in cold weather, yes - provided you have the range to spare. (Gas cars have the same issue BTW. No one really cares because their range is typically >300 miles and they "recharge" very quickly.)

BTW you don't "lose" the energy. If the battery stays cold, then the next time you recharge, it won't accept as much energy. If the battery warms up you get 95% of the range back (the remaining 5% has gone into warming up the pack, due to the higher ESR of the cold battery.) The energy doesn't just "go away."
Seems to me that every EV on the market is expensive and will work well depending on where you use them. Can't be too hot or too cold outside. I still drive an ICE car because I live in Canada and a full tank of gas will give me the same amount of range whether it's really hot or really cold or anywhere in between.
Nope. Range drops by ~19% if you go from 70F to 0F. Again, nobody cares because they already have a fairly long range and very short refueling times.

https://www.greencarreports.com/news/1100629_both-electric-and-gas-cars-lose-range-in-the-cold-electrics-just-lose-more
I really wish I could have an electric vehicle to replace the ICE one I use, but I can't move down South far enough for it to work well all year round.
So get a PHEV. Or a long range EV.

Or continue to use a gas car if you like; whatever works for you.
 
billvon said:
Seems to me that every EV on the market is expensive and will work well depending on where you use them. Can't be too hot or too cold outside. I still drive an ICE car because I live in Canada and a full tank of gas will give me the same amount of range whether it's really hot or really cold or anywhere in between.
Nope. Range drops by ~19% if you go from 70F to 0F. Again, nobody cares because they already have a fairly long range and very short refueling times.

19%? You really believe that? I have never experienced such a drop in 40 years of winter driving up here. Let's just let the experts enjoy their discussion about the Model 3 battery shall we?
 
mistercrash said:
19%? You really believe that?
Yes, since it's backed up both by the physics of internal combustion engines and actual data from car fleets.
I have never experienced such a drop in 40 years of winter driving up here.
Hmm. I did in NY; I drove to Boston a lot and I definitely noticed a difference in how much gas I ended up with after a 223 mile drive depending on the season.
 
liveforphysics said:
IMHO, the potting is for vibe and corrosion resistance, and the majority heat path is likely through the bottom of the cell.

This shot shows what I think is a cooling plate or channel between the cells.

http://www.motortrend.com/news/tesla-model-3-teardown-deconstructed-3/#tesla-model-3-teardown-9
 
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