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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

#411

Post by LilBytes »

sejl wrote: post #400
lmpdev wrote: post #369

Earlier quoted context omitted.

I get this a lot I work at an electronics store in Australia This week I had a customer dumbfounded why his 3,500W inverter almost caught fire He was using 8-gauge wire (~56A max) He needed 00-gauge (almost 300A max) If he’d have run the system at 48V instead of 12V he’d have saved $200+ per metre on cabling his inverter My advice on voltage selection for a vehicle is once you’re needing more than a few metres of 0-g…

I guess you work at Jaycar too? Always a fun conversation trying to explain voltage drop to someone who wants to cheap out on cable with our inverters and DC/DC chargers. I'm sure a 48V bus would solve all those F1 errors too.

That's funny, I assumed the same.

Not an employee, but a very happy reoccurring customer.

Re: Tesla shares 48V architecture with other automakers

#412

Post by jakewins »

hef19898 wrote: post #377
lmpdev wrote: post #369

Earlier quoted context omitted.

I get this a lot I work at an electronics store in Australia This week I had a customer dumbfounded why his 3,500W inverter almost caught fire He was using 8-gauge wire (~56A max) He needed 00-gauge (almost 300A max) If he’d have run the system at 48V instead of 12V he’d have saved $200+ per metre on cabling his inverter My advice on voltage selection for a vehicle is once you’re needing more than a few metres of 0-g…

Good look doing DIY work on the 48V network of a modern car, ICE or EV or 12, 24 or 48 V doesn't matter. And the past 12 V systems are dead easy to work on. On older cars that is, as soon as you have electronics and bus systems DIY basically requires deep car electronics knowledge and skills.

Do you have examples of what kind of DIY work is hard?

I haven’t done a ton of work on newer cars, but at least adding wiring for a hitch on my Kona EV was just as easy as any wiring I’ve done on my old truck.

Is a job like adding amps and better speakers trickier?

Re: Tesla shares 48V architecture with other automakers

#413

Post by carstenhag »

sokoloff wrote: post #382
jeffrallen wrote: post #356

Earlier quoted context omitted.

> requires extreme caution and safety procedures As long as the battery pack is still sealed and the interlock systems are undamaged and working correctly, it's no big deal. You follow the manufacturer's instructions to make it safe, then work on it like there's no voltage present. If the battery pack is broken or a prototype or whatever, yeah, then you need to think things through carefully before doing them. And ha…

GP was talking about the low voltage system (the 12-volt system in most cars) and choosing a voltage for it, not anything about the traction battery.

No, they were comparing the difference in precautions between 12/48v accessory battery and the 400/800V traction battery.

Re: Tesla shares 48V architecture with other automakers

#414

Post by dezgeg »

contingencies wrote: post #84
jnsaff2 wrote: post #83

The "expert" in the article got it wrong. The relationship between the voltage and the losses in the wires is not proportional. They are squared. Going from 12V to 48V is not a saving of 4x rather 16x. For some applications you could also consider Power over Ethernet in the car, get both shielded comms and power. Or can and power over twisted pair.

The great thing about PoE standards is there's so many to choose from. https://en.wikipedia.org/wiki/Power_over_Ethernet#Standards_... Honestly, ethernet introduces a degree of non-determinism with respect to time in the link layer, plus increased bringup times, a potentially more costly core switching fabric, and the need for critical revision of latency assumptions on any potentially safety-related control concerns…

Ethernet is already used to transmit radio signal over fiber which requires extremely tight variation in latency (probably more strict than automotive).

Re: Tesla shares 48V architecture with other automakers

#416

Post by t0mas88 »

avalys wrote: post #397
DannyBee wrote: post #272

Earlier quoted context omitted.

48V has been considered for automotive for decades. The problem was not know how. It simply has never been worth it before to retool things in practice. It's also electrically a lot more noisy. The limit of what is considered low volt is like 60v or something.

Mercedes-Benz has been using 48V systems since 2016. https://paultan.org/2016/10/31/mercedes-benz-reveals-first-d... This dynamic, where Tesla "announces" something that the rest of the industry has been doing for a while anyway, and a bunch of star-struck enthusiasts and stock manipulators tout it as an example of Tesla' "super smart innovation", is getting tiresome.

Jup happens all the time. Tesla also made the CyberTruck a drive by wire system, now fans are claiming it has the unique ability to have variable steering angles based on speed which is "far ahead of any other manufacturer"

Except that BMW 5-series and 7-series from 2010 onward have had this option... They've done it in a smarter way using a plantery gear system to keep a physical steering wheel connection as a backup instead of going the cheap and less safe drive by wire way that Tesla put on the CyberTruck.

Re: Tesla shares 48V architecture with other automakers

#417

Post by RamblingCTO »

jakewins wrote: post #412
hef19898 wrote: post #377

Earlier quoted context omitted.

Good look doing DIY work on the 48V network of a modern car, ICE or EV or 12, 24 or 48 V doesn't matter. And the past 12 V systems are dead easy to work on. On older cars that is, as soon as you have electronics and bus systems DIY basically requires deep car electronics knowledge and skills.

Do you have examples of what kind of DIY work is hard? I haven’t done a ton of work on newer cars, but at least adding wiring for a hitch on my Kona EV was just as easy as any wiring I’ve done on my old truck. Is a job like adding amps and better speakers trickier?

I have a defender and added a bunch of stuff to it: cruise control, motor pre-heater, rear camera, working lights in the rear. I'll also add a diesel heater and more electrics at some point. On 12V it's easy, can't imagine doing work like that with 48V. Not sure how this works, and if you maybe just can use 12V anyway. But wanted to make the point of camper vans and overlanders and offroaders.

Re: Tesla shares 48V architecture with other automakers

#418

Post by bluGill »

dreamcompiler wrote: post #257
bluGill wrote: post #64

Earlier quoted context omitted.

You would need larger wires to account for the losses at a house scale. Since nothing runs are 48 volts you still have the bad power supply in every LED bulb.

12 gauge wire would work fine for 48v lighting loads; probably 14 gauge too for many of them. Small DC constant-current sources are commodity items now and they're very efficient.

12 gauge is more expensive, and harder to work with.

Re: Tesla shares 48V architecture with other automakers

#419

Post by hef19898 »

grecy wrote: post #394
hef19898 wrote: post #378

Earlier quoted context omitted.

In automotive, it is usually the other way round. Regardless, what exactly was wrong with the existing 12 and 24 V systems for auxiliaries that absolutely needed to be changed?

The move to 48V means much less power is lost (power loss = (IxI)xR ), cables can be much smaller, cables and terminals can be much lighter and much less copper can be used used. Basically it's just a more efficient way of doing things. Elon has said it's not a revolution, or ground breaking in any way, it is simply a step improvement. Anyone could have done it. Tesla did it.

As others pointed out lready, others did it, too.

Re: Tesla shares 48V architecture with other automakers

#420

Post by hef19898 »

jakewins wrote: post #412
hef19898 wrote: post #377

Earlier quoted context omitted.

Good look doing DIY work on the 48V network of a modern car, ICE or EV or 12, 24 or 48 V doesn't matter. And the past 12 V systems are dead easy to work on. On older cars that is, as soon as you have electronics and bus systems DIY basically requires deep car electronics knowledge and skills.

Do you have examples of what kind of DIY work is hard? I haven’t done a ton of work on newer cars, but at least adding wiring for a hitch on my Kona EV was just as easy as any wiring I’ve done on my old truck. Is a job like adding amps and better speakers trickier?

Depends on where you connect stuff. Directly to some wiring loom that is already there? Bad idea, not all connected equipment will take the aditional loads well. Going directly to the car battery with dedicated wiring? Doable, but since start-stop is a thing, battery management and other stuff migjt not like that very well neither. Second batery? A bitch since start-stopp.

Hence, one needs some good knowledge around that, what to connect where.

In the old days, well, just go directly to the main battery with your aftermarket wiring and Bob's your uncle.

And none of that, battery management, which equipment can be connected where, has anything to do with the voltage but rather with all the other stuff modern cars have (bus management, battery management, ECus,...) all of which might or might not accept voltage and amp fluctuations very well.

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