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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

by gleenn 3y ago

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 3y ago
[deleted]
Turskarama 3y ago
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.
- Kirby64 3y ago
  Not true in most EVs regarding 'only the motors'. The AC/heat pump compressor is run off the HVDC, typically. Since it runs for long periods of time and consumes kilowatts, you want to run it straight off the main HV battery. Also, any vehicle that still uses resistive heating (older EVs tended to do this, Tesla included) use the HVDC for that.
- Moto7451 3y ago
  I’m speaking about the power planes. What they drive is irrelevant from the standpoint that higher voltage systems create safety issues that lower voltage systems do not have. No one is going to be ok with “occasionally being shocked by 48v” or “occasionally seeing arcing in their car from a high voltage system.” Running 48v to a radio is not an engineering marvel. Running it safely and reliably in an automotive environment full of vibration and weather is. If you can do that with 400v, I argue you can do it with 48v, so the secret sauce they’re sharing is less relevant than if they did this ten years ago.
  - Turskarama 3y ago
    I feel like you're mixing up points now, running 48V is fine _because_ the voltage is low enough that it's unlikely to kill anyone if you mess it up. The 400V system in the meantime has a lot more care taken and limiting the systems it works on to ONLY high power systems lessens the number of things that can go wrong.
nine_k 3y ago
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.
dreamcompiler 3y ago
Tesla uses 800v only to run the Cybertruck's drive motors. Every other electric load in the truck uses 48v. Both of these are much higher in the Cybertruck than all other Tesla models. All other Tesla models use 400v [IIRC] for the drive motors and 12v for everything else.
- 1970-01-01 3y ago
  Newer builds are using 16v lithium batteries for low voltage.
- Kirby64 3y ago
  Pretty sure the AC/heat pump on the Cybertruck runs off the 800V pack. Since it consumes so much power for long periods of time, it makes little sense to run it off the 48V. Existing other Tesla's use the main pack voltage for AC/heat pump.
  - dreamcompiler 3y ago
    Good point and makes sense.
inferiorhuman 3y ago
Mercedes introduced their 48V hybrid in 2016. Kia in 2018. Peugeot just introduced theirs this year. Jalopnik was talking about the "48V revolution" in 2017: https://jalopnik.com/everything-you-need-to-know-about-the-upcoming-48-volt-1790364465 https://jalopnik.com/everything-you-need-to-know-about-the-u...
- hef19898 3y ago
  At least once delivered early then? Sharing tech 6 years before their annoncement of sharing it! Alternative take: Everybody else was aware 48 V networks work as well for decades, there was just no real benefot in switching yet. And Tesla has nothing to do with it. What's next, Tesla annoncing they will share the revolutionary tech of windscreens and doors?
SV_BubbleTime 3y ago
>Who is using 400-800V systems? That sounds extremely dangerous. Every electric vehicle. And yes, it is dangerous to work on the HV circuit.
- Moto7451 3y ago
  Not all of them. The Kia Niro I’m driving as a rental this week has a 240v battery. Level 3 charging it feels wildly slow compared to my car. But yes, you’re right the increased voltages add a lot of risk that has to be managed.
  - crishoj 3y ago
    And, thankfully, high-voltage systems are extremely well-managed in EVs. Evidence in support of this claim is that EVs are statistically 4-5 times less likely to catch on fire compared to ICE vehicles. https://gmauthority.com/blog/2023/11/ev-fires-less-likely-than-ice-vehicle-fires-research-finds/ https://gmauthority.com/blog/2023/11/ev-fires-less-likely-th...

by gleenn 3y ago

deleted 3y ago

[deleted]

Turskarama 3y ago

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.

Kirby64 3y ago
Not true in most EVs regarding 'only the motors'. The AC/heat pump compressor is run off the HVDC, typically. Since it runs for long periods of time and consumes kilowatts, you want to run it straight off the main HV battery. Also, any vehicle that still uses resistive heating (older EVs tended to do this, Tesla included) use the HVDC for that.
Moto7451 3y ago
I’m speaking about the power planes. What they drive is irrelevant from the standpoint that higher voltage systems create safety issues that lower voltage systems do not have. No one is going to be ok with “occasionally being shocked by 48v” or “occasionally seeing arcing in their car from a high voltage system.” Running 48v to a radio is not an engineering marvel. Running it safely and reliably in an automotive environment full of vibration and weather is. If you can do that with 400v, I argue you can do it with 48v, so the secret sauce they’re sharing is less relevant than if they did this ten years ago.
- Turskarama 3y ago
  I feel like you're mixing up points now, running 48V is fine _because_ the voltage is low enough that it's unlikely to kill anyone if you mess it up. The 400V system in the meantime has a lot more care taken and limiting the systems it works on to ONLY high power systems lessens the number of things that can go wrong.

nine_k 3y ago

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.

dreamcompiler 3y ago

Tesla uses 800v only to run the Cybertruck's drive motors. Every other electric load in the truck uses 48v. Both of these are much higher in the Cybertruck than all other Tesla models. All other Tesla models use 400v [IIRC] for the drive motors and 12v for everything else.

1970-01-01 3y ago
Newer builds are using 16v lithium batteries for low voltage.
Kirby64 3y ago
Pretty sure the AC/heat pump on the Cybertruck runs off the 800V pack. Since it consumes so much power for long periods of time, it makes little sense to run it off the 48V. Existing other Tesla's use the main pack voltage for AC/heat pump.
- dreamcompiler 3y ago
  Good point and makes sense.

inferiorhuman 3y ago

Mercedes introduced their 48V hybrid in 2016. Kia in 2018. Peugeot just introduced theirs this year. Jalopnik was talking about the "48V revolution" in 2017: https://jalopnik.com/everything-you-need-to-know-about-the-upcoming-48-volt-1790364465 https://jalopnik.com/everything-you-need-to-know-about-the-u...

hef19898 3y ago
At least once delivered early then? Sharing tech 6 years before their annoncement of sharing it! Alternative take: Everybody else was aware 48 V networks work as well for decades, there was just no real benefot in switching yet. And Tesla has nothing to do with it. What's next, Tesla annoncing they will share the revolutionary tech of windscreens and doors?

SV_BubbleTime 3y ago

>Who is using 400-800V systems? That sounds extremely dangerous. Every electric vehicle. And yes, it is dangerous to work on the HV circuit.

Moto7451 3y ago
Not all of them. The Kia Niro I’m driving as a rental this week has a 240v battery. Level 3 charging it feels wildly slow compared to my car. But yes, you’re right the increased voltages add a lot of risk that has to be managed.
- crishoj 3y ago
  And, thankfully, high-voltage systems are extremely well-managed in EVs. Evidence in support of this claim is that EVs are statistically 4-5 times less likely to catch on fire compared to ICE vehicles. https://gmauthority.com/blog/2023/11/ev-fires-less-likely-than-ice-vehicle-fires-research-finds/ https://gmauthority.com/blog/2023/11/ev-fires-less-likely-th...