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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

#71

Post by bokohut »

rnk wrote: post #13
intrepidhero wrote: post #5

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.…

Just to add the basic idea, the amount of power is amps * volts. So to carry the same amount of energy with a higher voltage, you can you use less amps. The amount of amps impacts how big the wires are, lower amps need smaller wires and that means less space for wires but more importantly less weight of the wires. There is a lot of wiring in a car. Tesla claims this could be 1/4 the amount of copper wiring in an arti…

It may help some also to know what an amp actually is: 6.241x10^18 protons or electrons per 1 second of time passing a certain point. A single Amp is equal to 1 Coulomb and 1 Coulomb has 1 Joule of energy. I share this from my personal documentation in comprehension of understanding the unseen resulting from a device I am building to solve a personal energy storage problem. All open knowledge certainly but graphing these relationships into a visual depiction of the correlation has greatly assisted when talking to others that have ZERO knowledge about energy and power. Humans are nearly all 100% visual so explaining it with pictures presents A LOT of AHA moments for those without such comprehension.

The inverse relationship between amps and volts can also help: 50 volts * 24 Amps = 1200 Watts 100 Volts * 12 Amps = 1200 Watts 120 Volts * 10 Amps = 1200 Watts 150 Volts * 8 Amps = 1200 Watts 200 Volts * 6 Amps = 1200 Watts 240 Volts * 5 Amps = 1200 Watts 360 Volts * 3.333 Amps = 1200 Watts 480 Volts * 2.5 Amps = 1200 Watts 600 Volts * 2 Amps = 1200 Watts

Stay Healthy!

Re: Tesla shares 48V architecture with other automakers

#72

Post by panick21_ »

bryanlarsen wrote: post #67
pgeorgi wrote: post #66

Earlier quoted context omitted.

I'd fully expect other car makers to move to an exclusive 48V setup at some point. They just do it gradually: For the new model a part is replaced by its next-gen successor that is incompatible anyway? Put it on the 48V bus. Repeat until the 12V system is done away with - or force the issue when there are only a few components left, or downstep the 48V to 12V right in front of them, once that's cheaper than keeping t…

It'd be cheaper to delete the 12V bus entirely and add 48V -> 12V converters in front of legacy components, even if they needed several dozen of those converters.

I expect Tesla to still have a few components like that in the car.

Re: Tesla shares 48V architecture with other automakers

#73

Post by panick21_ »

myself248 wrote: post #60
intrepidhero wrote: post #5

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.…

Hi, automotive electrical is my job. There's quite a bit of very thick wiring in a car, not just the starter wire, but boring stuff like audio amplifiers, rear window defrosters, power seat motors. Those things don't draw a ton of power, like maybe just a few hundred watts, but at 12 volts even modest powers require extraordinarily thick wires, especially when you account for bundle derating. This requires large term…

Awesome to hear from an expert. Im looking forward to some teardowns to see how the set this all up.

Re: Tesla shares 48V architecture with other automakers

#74

Post by panick21_ »

PinguTS wrote: post #43
intrepidhero wrote: post #5

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.…

What many people underestimate is all the comfort stuff we have and use in modern vehicles. Most of the utilizes some sort of electric drive. Any electric drive requires power: * Power sliding windows * Power seats * Electric trunk * Power sliding roof * Electric mirrors Also other stuff: * heated back window * heated front window * heated seats * heated steering wheel Also the lights, even when they are LED they sti…

There is a lot more. There is a huge amount of safty equipment and sensors in modern car. That stuff that is not seen but its there as well.

Re: Tesla shares 48V architecture with other automakers

#75

Post by [deleted] »

intrepidhero wrote: post #25
pgeorgi wrote: post #9

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.

[deleted]

Re: Tesla shares 48V architecture with other automakers

#76

Post by panick21_ »

7e wrote: post #36

Mild hybrids have been using 48V for a long time. There isn't much new here except that Tesla decided to do every component. That's going to cause quality problems with parts if they remain a tech. island in the industry, so trying to get everyone else on board makes sense.

Doing it for everything is the whole point, it changes the architecture of the car. Yes individual components but those cars had like 1% if connected devices at that voltage and were otherwise exactly the same.

For Tesla ist a replacment of something else, for previous vehicle was it was something additional for a specialized use case.

Re: Tesla shares 48V architecture with other automakers

#77

Post by atoav »

jabl wrote: post #69
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.

> I've seen estimates of $1000 in reduced cost due to reduced copper wiring What about aluminum wiring? Lighter, cheaper, though bulkier than equivalent copper. Aluminum wiring got a bad rep back in the day, but it seems with current electrical aluminum standards it supposedly works pretty well.

In sotuations where it is about space you wouldn't choose aluminum. Also afaik most automotive wiring that is certified is copper. Going from copper to aluminum means you will have to put bigger crossections in. This is more weight and more space.

Re: Tesla shares 48V architecture with other automakers

#79

Post by amluto »

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 find 48V a lot less scary when cars are involved than 12V. Neither is particularly likely to electrocute me, but 48V comes with fuses that will trip at 1/4 the current, giving 1/16 the resistive heating if something shorts, which is a lot less likely to melt or ignite things. Also, the wires are much smaller :)

Re: Tesla shares 48V architecture with other automakers

#80

Post by vlovich123 »

bokohut wrote: post #70
candiddevmike wrote: post #45

Earlier quoted context omitted.

Replace all power outlets with Ethernet and have everything run over 48V PoE and get network connectivity too

While this sounds great in practice the reality will be far from ideal for the singular reason of security. The cyber issues are compounding at exponential rates as more and more devices that make things "easy" lack even the most basic security protocols and the production targets to generate revenue asap have zero to nil concern around protecting said devices from nefarious actors while in use. When the electrical a…

More like basically every electronics product uses AC. It’s a two sided market problem - there’s no demand because there’s no supply and no supply because there’s no demand.

The security aspects are solvable through various standards (eg we have LAN over power lines and coax already and they layer encryption on top to build the mesh while balancing UX). The security concerns may be the #1 concern for you but has nothing to do with market adoption.

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