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Hacker mods an M1 Mac mini to receive power over Ethernet instead of AC

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Re: Hacker mods an M1 Mac mini to receive power over Ethernet instead of AC

#151

Post by dreamcompiler »

WWLink wrote: post #76
r00fus wrote: post #19

Earlier quoted context omitted.

What's the goal of having a MacMini running off an external battery? I mean, it seems less cost effective than just getting a MB Air and not using the screen...

Headless servers where you want a modular or easily removable battery backup. I really wish desktop PC power supplies would support such a thing. It seems stupid that we need to use a UPS with an inverter when the power supply should be rigged to accept DC input straight from a battery.

That's where USB-C PD is nice. It's all DC at several different voltages the recipient can request. The only downside is it's not quite powerful enough for many desktop PCs, but it's getting better.

Re: Hacker mods an M1 Mac mini to receive power over Ethernet instead of AC

#152

Post by bravetraveler »

shagie wrote: post #90
bravetraveler wrote: post #79

Earlier quoted context omitted.

Thank you for taking the time to follow up! Definitely a bit paranoid - even if I'd prefer to call it robust :) I've had very bad luck in this regard... but haven't honestly used a laptop in probably a decade. I was pleasantly surprised to see my latest (dust-collecting) Lenovo will stop somewhere around 80%! Point being, sure - there are safety things... but batteries are consumables. I like these things to be easy-…

> ... but batteries are consumables. I like these things to be easy-to-replace! Replaceable, consumable batteries often get thrown out in the trash. ... and can set garbage trucks and recycling centers on fire. https://www.waste360.com/safety/lithium-ion-batteries-are-ca... https://www.dispatch.com/story/news/local/2023/02/09/garbage... https://arstechnica.com/gadgets/2022/12/recycling-firm-fined... https://gothamist…

I wish I knew a good answer - this is an excellent concern. I'm skeptical of recyclers/waste centers, but that's what I've got.

Re: Hacker mods an M1 Mac mini to receive power over Ethernet instead of AC

#153

Post by appletrotter »

cesarb wrote: post #114
abakker wrote: post #94

Earlier quoted context omitted.

Transmission losses in DC are higher, so you need a lot more wire. You actually can get off the shelf low voltage lighting, though, but it tends to be high end designer stuff.

> Transmission losses in DC are higher For the same voltage and wire size, transmission losses in DC are the same or lower (due to skin effect and capacitive/inductive losses). They are only higher when comparing low-voltage DC with higher-voltage AC, but the key difference is the voltage, not DC versus AC. (As a bonus, DC has lower peak voltage for the same RMS voltage, so the wires need less insulation.)

Sure, but GP and OP are talking about supplying power at the voltages devices (such as LEDs) currently consume.

AC is associated with higher voltage in this context even if that isn’t intrinsic.

Re: Hacker mods an M1 Mac mini to receive power over Ethernet instead of AC

#154

Post by twoodfin »

dreamcompiler wrote: post #151
WWLink wrote: post #76

Earlier quoted context omitted.

Headless servers where you want a modular or easily removable battery backup. I really wish desktop PC power supplies would support such a thing. It seems stupid that we need to use a UPS with an inverter when the power supply should be rigged to accept DC input straight from a battery.

That's where USB-C PD is nice. It's all DC at several different voltages the recipient can request. The only downside is it's not quite powerful enough for many desktop PCs, but it's getting better.

Pretty much expect the Mini to end up this way within a few generations. Somebody in the Mac team really hates wall warts, but given all their other hardware is going USB-C one would think they’d want to standardize & eliminate the space/heat of the internal power supply.

Re: Hacker mods an M1 Mac mini to receive power over Ethernet instead of AC

#155

Post by Someone »

bravetraveler wrote: post #27
r00fus wrote: post #19

Earlier quoted context omitted.

What's the goal of having a MacMini running off an external battery? I mean, it seems less cost effective than just getting a MB Air and not using the screen...

Avoiding the inevitable spicy pillow seems like a good reason An external/easily replaceable battery would be excellent come time to deal with cell age

The article is about a Mac Mini. Those machines are mains powered, not battery powered.

Re: Hacker mods an M1 Mac mini to receive power over Ethernet instead of AC

#156

Post by ravetcofx »

throwaway894345 wrote: post #148
ravetcofx wrote: post #6

" the M1 Mac mini was the perfect hardware to test out PoE, as on idle, the device only consumes 6W. When some load is applied to the internals, that power draw can go up to 40W. After some thorough research, we found out that the maximum throughput of Power over Ethernet was 15.4W " They'll have to bump it up to 802.3bt (Poe ++) which can support 60W. Cool Project though, I've been wanting to mod my Mac Mini m1 to r…

I’d be very curious to understand (even very crudely) the breakdown of those 40W. Roughly how much does each internal component consume at its peak load? Or at least for the top offenders.

80%+ will be the M1/M2 SOC with it's on package Ram, ~5% will be SSD, 5%-10% Fan, remaining will be supporting circuitry (buck converters, regulators etc)

Re: Hacker mods an M1 Mac mini to receive power over Ethernet instead of AC

#157

Post by bravetraveler »

Someone wrote: post #155
bravetraveler wrote: post #27

Earlier quoted context omitted.

Avoiding the inevitable spicy pillow seems like a good reason An external/easily replaceable battery would be excellent come time to deal with cell age

The article is about a Mac Mini. Those machines are mains powered, not battery powered.

I was replying to a question on why one wouldn't "just get a MB Air/not use the screen"... not the article.

How is this relevant? I don't say this to be rude, but this internet phenomenon of relentless pedantry is annoying.

Things tend to make [some degree of] sense when your first reaction isn't to shoot from the hip.

Mains batteries exist - most people should save the effort, get a UPS. Hackers on the other hand... it's kind of silly to ask why. The answer is 'because'.

Re: Hacker mods an M1 Mac mini to receive power over Ethernet instead of AC

#158

Post by NavinF »

dheera wrote: post #107
wolrah wrote: post #67

Earlier quoted context omitted.

> Sure it could be the RPi hat, but it just means the standard is so complicated that people don't implement it correctly. Or there are ways to cheap out on a PoE device that may work in some cases but don't fully and properly implement the standard. The standard is widely used in VoIP phones, wireless access points, security cameras, and all sorts of other networked devices that get installed in places that may not…

I mean, one of my hats that fried one of my Pis was a Waveshare hat. This one actually https://www.amazon.com/gp/product/B0974TK3KD/ PoE operates at a pretty high voltage (almost half of line voltage!) and Waveshare products aren't UL listed.

>PoE operates at a pretty high voltage

No, it operates at ELV (extra-low voltage): https://en.wikipedia.org/wiki/Extra-low_voltage

The whole point of PoE, 48V PD USB-C, and similar tech is that they don't need to be UL listed. PoE is also electronically current limited unlike mains power so you can't pull 200A to start a motor nor can you start fires without a lot of effort. That's assuming you use a real PoE switch that negotiates power levels, not cheap passive injectors.

Anyway that hat has some bad reviews claiming DoA, missing components, and dead Pis. Why not get the official hat? https://www.raspberrypi.com/products/poe-hat/

Re: Hacker mods an M1 Mac mini to receive power over Ethernet instead of AC

#159

Post by smileybarry »

sbierwagen wrote: post #96
skinkestek wrote: post #93

I've been wondering more than once if we couldn't improve (larger) offices a lot by distributing power pre-transformed so every computer and every screen wouldn't have to include a transformer. I also sometimes wonder why these days, when every new lamp is led, why we don't replace most of the dangerous 230V outlets in new houses with 12V and use 230V only for dishwashers, laundry machines, dryers and that kind of st…

Many IP phones are PoE. Ubiquiti used to sell PoE office lighting, oddly enough. Now discontinued https://www.bhphotovideo.com/c/product/1431160-REG/ubiquiti_...

It's kind of cool that you'd control lighting over IP supplied via the same PoE port, but a missed opportunity to not offer a unit with an AP inside.

Re: Hacker mods an M1 Mac mini to receive power over Ethernet instead of AC

#160

Post by smileybarry »

t3rabytes wrote: post #146
awiesenhofer wrote: post #143

Earlier quoted context omitted.

I have this vision of a future where everything just runs off of usb-c and usb-pd. Even today, expect in the kitchen and the bathroom (refrigerator, washing machine,...) you could totally run most things off of the 240w max. Much more so in an office. It would be so much more efficient than what we have now, and safer. No idea how realistic it is though...

I pulled the specs for a dual-compressor fridge this morning for an unrelated reason and it only draws 180w... maybe the fridge can run on usb-c too! https://www.bosch-home.com/us/productslist/refrigerators/fri...

Something about a giant fridge being powered by some small Apple brick gives me shivers. I guess it's doable but it feels wrong.
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