441–450 of 504 posts
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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.
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.
> Or can and power over twisted pair. I was reading an anti-Musk subreddit over on Reddit and I think the cybertruck is doing this? They were mad that the cybertruck uses 48V and Ethernet cables, but to me, that seems perfect for CAN and power. We already use 48V (or similar) for PoE, and CAN needs a twisted pair... so why not buy that off the shelf instead of using a custom wiring harness? I don't think the cybertru…
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>potentially improves overall electrical efficiency Looks like he understood it the entire time :)
I wasn't sure, so I asked: > Higher voltage systems experience lower power losses over the same distance compared to lower voltage systems. This is due to the fact that power loss in a conductor is proportional to the square of the current. By using higher voltage, you can transmit the same amount of power with less current, reducing resistive losses in the wires.
(V^2)/R
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Remember a fully charged lithium battery with nominal 48v can be close to 60v just like 12v in your car is actually closer to 14v.
Sure but they can feed the system through a regulator if they'd like. Do we have any reason to believe they are tapping directly on to a pack for this part of the system?
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And a TD5 is already modern-ish enough, but very nice regardless! Personally, I would be at a loss working in anything built after the early 80s, so for a Defender that would be the dual-carb V8s, and 200/300 TDis. My 1982 Range Rover has all of three fuses, so electrically I'm fine! Except the mess previous owners did to the original wiring... No idea why it is so difficult to just make your own wiring for after mar…
Yeah I don't touch anything in the box beneath the passenger front seat ;) The previous owner thankfully already fixed the "oil creeps up the wires" issue, so I can leave it. Nothing I'm too keen on, but simple enough I figure. > I have no idea why it works so... I know that feeling haha. Adding wiring is so much easier than ripping up existing stuff ...
Many comments here seem to be confusing the accessories circuit voltage with the electrical vehicle motor and drive system. The vehicle motors have a combined power output of 450KW which requires a high voltage 800V system or the wiring would be so heavy it would not be feasible. This spec appears to be the accessories circuit with Tesla pushing for a new 48V standard. That’s super smart because it immediately means…
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…
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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.
That's a complete misunderstanding of what Tesla did. Having a component in the car that is 48V and having the whole car being on a 48V PoE architecture are totally different things. The sad part is that these company actually have the beginning of a 48V system but never actually pushed threw and did it all. This is like when SpaceX landed a first stage and everybody was like 'DC-X did it SpaceX did nothing new'. The…
Previous 48V systems were only partial for good reason as well - traditional manufacturers have been using "mild hybrid" 48V systems since ~2001. Many of the electrical components on ICE vehicles are parasitic engine loads since they need power than can be provided with 12V, so e.g. the water pump and AC compressor have separate belts that always are 'robbing' the engine power regardless if they're needed or not. Adding that 48V system allows for the engine to be freed from the draw that those components require and adding some light regenerative braking is sufficient to keep the batteries supplying that system charged.
That these 48v systems aren't universal should provide some color on how successful / important the manufacturers had found them to be.
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He's an engineeer that worked through this with other engineers from first principles. You're spreading bullshit with 2 seconds of effort.
Who? Because you can't mean Elon, not if your objection is to people spreading bullshit...
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Its the same with aluminum casting. The car makers used the technology once in a while in some specific parts, Tesla was like 'why not make half the car out of one casting'. Tesla worked closely with a supplier, did lots of its own research and development and continue to work with a supplier to make the technology better over time. This was considered stupid at first. This is now very widely copied. First automakers…
A quick search turned up this: >> S&P Global Mobility forecasts 15% to 20% of traditional body-in-white (BIW) stampings in 2030 may be at risk from these gigacastings. Underbody components typically comprise about 50% of a vehicle's BIW shell, and this soft underbelly is the target of gigacasting's focus. Source: https://www.spglobal.com/mobility/en/research-analysis/gigac... Obviously not a technical journal, nor di…
The majority of cars sold then will be existing models with minor updates.
And car companies only upgrade their major platforms every 5-7 years. Many companies are currently planning their second (or first real) EV platform.
But by 2030 even the waste number of EV will be on first generation EV platforms still.
Companies have 100s of million invested in their current body lines. So unless you build a totally new factory you are not gone adopt this technology.
When Toyota came out with their production system it took decades for all the practices to become established.