Investor Engineering Discussions

[mongo]

Why wouldn't humidity condense on the coils like any other air conditioner? All my heat pumps have water drain lines and dehumidifier settings.

No idea, but this one doesn't.

It may have a humidity sensor and keeps the coils above the dew point.
[But that would be weird, what model #?]

 

[JRP3]

All energy to the fridge is waste heat.
Efficency is how much energy is required to

• transfer energy from the food to the room (which itself is also waste heat, until food is removed)
• cancel the heat gain due to imperfect insulation

Any appliance's usage becomes waste heat in a closed system (other than endothermic cooking processes)

Yup, I wasn't thinking about it correctly, all energy used by the fridge does get put into the surrounding air.

 

[mongo]

Yup, I wasn't thinking about it correctly, all energy used by the fridge does get put into the surrounding air.

It would be an interesting trick question for a thermo exam.
I started to calculate what 80% efficient would even mean, but it's a holiday and my brain wasn't feeling it.

 

[jerry33]

It may have a humidity sensor and keeps the coils above the dew point.
[But that would be weird, what model #?]

Nevermind. I see it's just an A/C although it was sold to me as a heat pump.

 

[Oil4AsphaultOnly]

Nevermind. I see it's just an A/C although it was sold to me as a heat pump.

A/C's are essentially unidirectional heat pumps. Heat pump units are reversible (can provide cooling as well as heating).

 

[Doggydogworld]

The BMS might've failed out of warranty, or it could be a salvage vehicle that wasn't properly repaired. Whatever the case, it's not a given that the battery pack was bad.

Jason says 99% of them need a pack replacement.

 

[Oil4AsphaultOnly]

Jason says 99% of them need a pack replacement.

The point was that the seller should NOT have reset the BMS and sold the car!

We don't know how the seller came about with a car that needed a battery pack replacement, but the problem is that the seller encountered a fault, reset the BMS and then sold the cars to unsuspecting buyers. Buyers who TSLAQ have been citing as people who bought a Tesla that "looked" fine and encountered a battery issue that required a $20k replacement shortly after. Sorry if that wasn't clarified in my earlier response.

 

[MP3Mike]

We don't know how the seller came about with a car that needed a battery pack replacement, but the problem is that the seller encountered a fault, reset the BMS and then sold the cars to unsuspecting buyers.

We also don't know if the seller knew reseting the BMS was a problem. They may have taken it to a shop that told them it was a real fix.

 

[mongo]

I'd be interested in seeing that from wk057, he generally has pretty insightful commentary on the setups. Perhaps indeed newer inverters can accept such, but if you say the FSD computer sends it's "desired position and how it would like to get there", that would imply the inverter has some knowledge of things like current location, car orientation, steering angles, etc... things I'd expect FSD to know rather than the inverter... and I doubt the inverter is being told about them real time.

I could see the inverter being given things like time/distance/acceleration maximums (i.e. g-force limits), and it then calculating the torque commands necessary to do that...

I will try to dig a bit more to see if I can find it again

I'm sure there can be another way to be done, but I think it's interesting that Tesla went this way instead of the FSD computer commanding torque and speed, and with multiple cross check on the way

And also my main point is, is this easy to change? SHOULD it be changed? Probably a big reason to be done like that

The thread:

https://twitter.com/x/status/1591893573548781570

 

[scaesare]

The thread:

https://twitter.com/x/status/1591893573548781570

Thanks, it appears it does exactly this as I mentioned above: "I'd like to get X far in Y amount of time."

 

[JRP3]

Data point, Model 3 with 369K miles on original pack, motors and brakes

https://twitter.com/x/status/1664438564531187713

 

[mongo]

Not sure I knew this. Any teardown vids you are aware of?

I suppose I could always go look at Munro's stuff...

 

[willow_hiller]

Large thread of details about Highland, from Teslascope:

https://twitter.com/x/status/1671956434878345218

Some highlights:
1. Steer-by-wire
2. RGB ambient lights
3. Focus on recycled materials
4. HW4, new front facia and bumper camera
5. Launch any time between Q3 2023 and Q1 2024

 

[MC3OZ]

Toyota Claims Solid-State Battery Has 745 Mile Range, 10 Minute Charging Time - CleanTechnica

Toyota announced this week that it is closer than ever to manufacturing solid-state batteries for its future electric cars.

cleantechnica.com

batteries | Toyota Industries Corporation

Toyota Industries Corporation was founded in 1926 by Sakichi Toyoda to manufacture and sell the automatic looms which he had invented. Since then Toyota Industries has diversified and expanded the scope of its business domains to include textile machinery

www.toyota-industries.com

As the term “bipolar” indicates, the current collector can be shared by a cathode and an anode. This technique reduces the number of parts and thus enables the battery to be made more compact. It is also possible to stack a larger number of cells. In addition, since bipolar batteries have a wider electrical path and a simpler construction, there is lower resistance within the battery itself. This enables the flow of larger currents, achieving approximately twice the output of the conventional nickel-metal hydride battery equipped in the previous-generation Aqua.

I don't think Toyota's battery technology is "smoke and mirrors", but I also don't think it represents a serious challenge to Tesla anytime soon.

IMO Tesla also has some serious battery innovations in the pipeline and for the next decade price and volume are the most important metrics.

 

[-=buzz=-]

Isn't the bipolar setup basically building a serial circuit within a single cell?
So the cell voltage would be higher?
Might be a reasonable production improvement for large prismatic cells which are cut into pieces anyway, but could eliminate all the tabs except the top and bottom ones?

 

[MC3OZ]

Isn't the bipolar setup basically building a serial circuit within a single cell?

Yes, there is a helpful diagram from Toyota in the document I linked.

I don't have the information handy, but there is some connection between their solid-sate battery and their bipolar cell.

I think they are doing innovative R&D, which is why it is taking so long.

Even if the resulting battery is great, the other relevant questions come into play:-

1. Longevity - how many cycles?
2. Yield / fault rate - production quality.
3. Ability to scale- how long for multiple GWh of production?
4. Cost - how much per kWh?

if I was Toyota I would start by making the best battery possible, then work on 1.-4.

If a great solution for all problems is 20 years into the future, I don't think Tesla needs to be overly worried about this, Toyota has some tough hurdles to clear in the next 5-10 years just to remain a significant part of the industry.

 

[willow_hiller]

I know this isn't the Investor Chemistry Discussions thread, but just in case anyone among us has a chemistry background, I've noticed something strange about the information included with the shipments of the Burnt Hair perfume. Here's the information card included in the box:

The thing that stands out is "Isoeugenol." Generally speaking, it's an essential oil that naturally occurs in wood smoke, but can be synthesized and is used as a precursor in the synthesis of other chemicals (e.g. vanillin). Makes sense that it's where the perfume gets its smokey scent, but legally speaking, could have been included as a component of "Parfum" and didn't need to be explicitly identified.

The conspiratorial part of me is wondering whether Isoeugenol is being used in, or is a byproduct of, some other chemical process by the Boring Company/Tesla/SpaceX. Tried looking for possible links to battery chemistry, only thing I can find is from Google Search Generative AI, but I cannot tell if it's just hallucinating.

Thoughts?

 

[JRP3]

I've never heard of it in a battery, I'd lean towards hallucinating. Seems to be a standard component of perfumes.

 

[mongo]

Much harder problem that charge connector on the implementation side. Maybe that is really what they need dojo for in the future, to retrain on different geometry cars/camera systems, massive amounts of new data needed. What storage vendor does Tesla use?

Theoretically, only the front end camera->voxel mapping portion would need to update.
However, it seems like Tesla is talking end-to-end all in one NN these days which removes such boundaries. In which case, yeah need to retrain with the new feeds or back-processed versions of the existing fleet data (more likely).

 

[Artful Dodger]

In a webinar for Charged EV Mitch Marks discusses unleashing the power of cutting-edge ... (45:53)

Motor Bouillabaisse - Latest Trends in Electric Motor Testing | Charged EV on Youtube