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Tesla shares 48V architecture with other automakers

electrek.co

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Re: Tesla shares 48V architecture with other automakers

#211

Post by reportingsjr »

jauntywundrkind wrote: post #31
elp wrote: post #11

48Vdc is supposedly the highest voltage that is still considered safe. ( https://electronics.stackexchange.com/questions/267789/how-s... ) It certainly sounds like a smart move on the copper savings alone.

Extra low voltage is 50v ac or 100v dv. https://en.wikipedia.org/wiki/Extra-low_voltage For some reason people assume it's 48v DC or 50v dc. But it's double that. That said, I feel significantly more scared dealing with 100v DC than I do 48 or 24v.

I have been shocked by 110V DC and let me tell you, it hurts. A lot. Would not recommend.

Re: Tesla shares 48V architecture with other automakers

#212

Post by gleenn »

Moto7451 wrote: post #189

Audi also has a 48v architecture in use for mild hybrids like my SQ5. This is an older article but explains it well https://www.greencarcongress.com/2017/06/20170602-audi.html My 2021 is fully 48v except for an inverter for necessary 12v circuits (like cigarette outlets and the jumper pins) and a small motorcycle battery that is used for minimal 12v functionality. The mild hybrid battery is under the rear seats and s…

My understanding was that nearly every production vehicle on the road is 12V and that Tesla and perhaps Audi as you mentioned are doing things differently. Who is using 400-800V systems? That sounds extremely dangerous.

Re: Tesla shares 48V architecture with other automakers

#213

Post by [deleted] »

gleenn wrote: post #212
Moto7451 wrote: post #189

Audi also has a 48v architecture in use for mild hybrids like my SQ5. This is an older article but explains it well https://www.greencarcongress.com/2017/06/20170602-audi.html My 2021 is fully 48v except for an inverter for necessary 12v circuits (like cigarette outlets and the jumper pins) and a small motorcycle battery that is used for minimal 12v functionality. The mild hybrid battery is under the rear seats and s…

My understanding was that nearly every production vehicle on the road is 12V and that Tesla and perhaps Audi as you mentioned are doing things differently. Who is using 400-800V systems? That sounds extremely dangerous.

[deleted]

Re: Tesla shares 48V architecture with other automakers

#214

Post by elihu »

rational_indian wrote: post #26

Could have gone higher. Worth it in copper savings alone. IIRC the cars use AC motors. It needs to go through inverters anyway so there is some flexibility in how high you can go. Edit: of course the motors are "AC" who would want a brush and commutator based motor in their car?

The terminology can get confusing. I many contexts, a "brushless DC motor" is actually a 3-phase AC motor.

The idea is that you can think of the motor and motor controller (often called an inverter) together as a DC motor because the input to the motor controller is DC.

Series-wound DC motors used to be fairly common for EV conversions, and they're still a reasonable choice if you want something that's very cheap and very powerful, and don't care about brush maintenance, efficiency, regen, or being able to reverse easily. (The White Zombie for instance uses a pair of SWDC motors.) Normal people just use AC motors these days.

Re: Tesla shares 48V architecture with other automakers

#215

Post by ReactiveJelly »

Moto7451 wrote: post #189

Audi also has a 48v architecture in use for mild hybrids like my SQ5. This is an older article but explains it well https://www.greencarcongress.com/2017/06/20170602-audi.html My 2021 is fully 48v except for an inverter for necessary 12v circuits (like cigarette outlets and the jumper pins) and a small motorcycle battery that is used for minimal 12v functionality. The mild hybrid battery is under the rear seats and s…

Not sure how relevant this is, but curious readers might be interested: In those 400-800 volt systems, the low-voltage system is used to wake up the battery's computer and close a normally-open contactor inside the battery that connects the high-voltage system.

So indeed they might not ground HV stuff to the chassis, and the hundreds-of-volts sources are disconnected if the car is turned off and unplugged.

Re: Tesla shares 48V architecture with other automakers

#216

Post by bryanlarsen »

Kirby64 wrote: post #100
bryanlarsen wrote: post #63

Earlier quoted context omitted.

No benefit? I've seen estimates of $1000 in reduced cost due to reduced copper wiring, and more importantly the labor required to string that wiring. Modern phones charge on 48V these days, so 48V parts are extremely common & cheap.

What modern phone charges at 48V? I'm not aware of any that charge at even 20V, outside of a couple of gimmick devices. No Samsung or Apple phone charges at anywhere close to that, that's for sure.

I believe Qualcomm's QuickCharge 5 can use the full 48V of USB-PD. Given it allows 100W, I certainly hope so.

Regardless, QuickCharge 3 is 20V and it's been in a lot of phones since it was introduced in 2016.

Re: Tesla shares 48V architecture with other automakers

#217

Post by bsza »

jmrm wrote: post #141

>48V architecture also potentially improves overall electrical efficiency for reasons that I am not sufficiently qualified to explain beyond a kindergarten level This is double bad in a green energy and EV website: On one hand, they admit they don't now why that happens, but on the other hand, they also didn't research just a bit more on that, and that's bad journalism. Most of the comment threads in this HN post are…

> they admit they don't now why that happens

No, they said “not sufficiently qualified to explain”. Which is not the same as not knowing, given that the same phenomenon can be explained on a lot of different levels depending on when you get tired of asking “why?” - see this video of Richard Feynman “explaining” magnets: https://m.youtube.com/watch?v=MO0r930Sn_8

Re: Tesla shares 48V architecture with other automakers

#218

Post by Turskarama »

gleenn wrote: post #212
Moto7451 wrote: post #189

Audi also has a 48v architecture in use for mild hybrids like my SQ5. This is an older article but explains it well https://www.greencarcongress.com/2017/06/20170602-audi.html My 2021 is fully 48v except for an inverter for necessary 12v circuits (like cigarette outlets and the jumper pins) and a small motorcycle battery that is used for minimal 12v functionality. The mild hybrid battery is under the rear seats and s…

My understanding was that nearly every production vehicle on the road is 12V and that Tesla and perhaps Audi as you mentioned are doing things differently. Who is using 400-800V systems? That sounds extremely dangerous.

They're getting mixed up, the 400-800V systems are _only_ for the motors, everything else in the car still uses low voltage.

In fact, afaik every single electric car has two separate systems. There's a high voltage system (the main battery and motor(s)) and the low voltage (almost always 12v) system, usually with a traditional lead-acid 12v battery that is charged via a DC-DC converter connected to the high voltage battery.

Re: Tesla shares 48V architecture with other automakers

#219

Post by nine_k »

gleenn wrote: post #212
Moto7451 wrote: post #189

Audi also has a 48v architecture in use for mild hybrids like my SQ5. This is an older article but explains it well https://www.greencarcongress.com/2017/06/20170602-audi.html My 2021 is fully 48v except for an inverter for necessary 12v circuits (like cigarette outlets and the jumper pins) and a small motorcycle battery that is used for minimal 12v functionality. The mild hybrid battery is under the rear seats and s…

My understanding was that nearly every production vehicle on the road is 12V and that Tesla and perhaps Audi as you mentioned are doing things differently. Who is using 400-800V systems? That sounds extremely dangerous.

A ton of trucks are 24V, especially in EU. 48V in automotive industry is something new; I can't remember seeing it on any commercial trucks.

Electric bikes use 12V, 24V, 28V and even 56V. Nobody loves the weight and the cost of thick copper wires.

400V or 800V are charging voltages, because it's the operation with the highest current; to keep it manageable while transferring more energy you need really high voltages. AFAICT, motors inside a Tesla use 320V. I suppose that ICE-electric hybrids also use some reasonably high voltage to feed the electric motors.

Re: Tesla shares 48V architecture with other automakers

#220

Post by LeoPanthera »

jmrm wrote: post #141

>48V architecture also potentially improves overall electrical efficiency for reasons that I am not sufficiently qualified to explain beyond a kindergarten level This is double bad in a green energy and EV website: On one hand, they admit they don't now why that happens, but on the other hand, they also didn't research just a bit more on that, and that's bad journalism. Most of the comment threads in this HN post are…

This is not too surprising for Electrek, which is run by Tesla/Elon fanboys and mostly got popular by accident during the rise of the EV.

I like Ars Technica's car coverage: https://arstechnica.com/cars/

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