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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.
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.
Earlier quoted context omitted.
https://de.wikipedia.org/wiki/Bordnetz#48-Volt-Bordnetz_im_A... explains (a bit) why German car makers are using 48V since ~2016 (in addition to the still existing 12V system, which seems to be the difference with Tesla, which went 48V-only). DeepL translation: The 12 V electrical system can barely cover the power consumption that modern vehicles need for their comfort systems. The "static" consumers completely overl…
A split 48/12 system makes a lot more sense. Run the heater/heat pump, power steering, coolant pump, etc on 48V and keep entertainment and controls on 12V.
Doesn't that raise collusion/anti competitive concerns? Or is Elon relying on the fact no prosecutor will take a case about disadvantaging china?
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?
If you look at current cars there are sometimes huge cable bundles, lots of individual cables for everything. Its a nightmare to build up and very hard to install.
I think in their next generation assembly they will have these connection points be fixed and then just plug different sub assembly together at predetermined points. No more huge cable harness installed on completed bodies.
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?
Most countries have safety rules that apply at 50V, so staying below that reduces regulatory costs significantly.
Why would a car need a 48V system for accessories? In general the things a car's 12V system powers have gotten less power hungry over time (LED's, heat pump) and in particular, an EV loses the highest power electrical device on the 12V bus, the starter. The typical equipment used for the entertainment and control systems are going to be much more available with 12V supplies, just because that's the industry standard.…
Not that anyone is going to stick a plow on a Cybertruck, but holy shit is the hydraulic pump on one of those a huge current draw. It's 4AWG wire on mine. The battery is kind of marginal[0] and when I raise the plow, the volt meter goes down to 7-8 volts if the engine's at idle and the alternator can't supply the needed current. Gunning the engine improves the situation somewhat, but wow, was that an eye opener. [0]…
- moving the voltage up means you can drop current
- increase the data rate by using ethernet and PoE
- using ethernet and PoE means you don’t have to run one off wires to each device, they can share a bus which results in half the copper being used in a lower voltage car
- moving the voltage up also means reduced heat produced
Earlier quoted context omitted.
Agreed. 48V (actually -48V) has been used across telco central offices for decades.
How exactly do you define a negative voltage unless you are using some other voltage as a reference?
Voltages are all relative. It's like saying 'How do you get a height difference of 10 feet by digging?'
Well, you dig and then label the initial level as +10 feet, and redefine the bottom of your hole to be ground.