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Hardware Hacking Debian Desktops (Apple) Power Hardware

Mac mini Sans Wires - Batteries Inside the Case 317

Posted by timothy
from the why-do-you-ask-why dept.
An anonymous reader writes "Running Debian (or Linux generally) on a Mac mini is old news. Silas installed rechargable batteries inside the case, delivering a couple of hours of runtime while retaining the small form factor. Although it runs fine without wires, he had to plug in the monitor to be able to show that it was really up."
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Mac mini Sans Wires - Batteries Inside the Case

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  • iMac (Score:2, Interesting)

    by Mensa Babe (675349)
    Using an iMac would be a better idea, for it has a monitor already included.
    • Yes, but (Score:5, Insightful)

      by killa62 (828317) on Wednesday May 18, 2005 @10:00AM (#12566051)
      the monitor would drain the batteries like hell
      • Re:Yes, but (Score:4, Insightful)

        by mbbac (568880) on Wednesday May 18, 2005 @11:11AM (#12566798)
        What is the point in a headless computer that runs from batteries?
        • Re:Yes, but (Score:5, Interesting)

          by WD_40 (156877) on Wednesday May 18, 2005 @11:26AM (#12566927) Homepage
          A small-footprint webserver with a built-in UPS.
          • You mean an iBook?
            • The iBook is not headless, and therefore does not fit the requirement of a headless computer with a battery.
          • Except it's (currently) not, since according to the article he can't run it while both the power & batteries are plugged in, otherwise it would overcharge the batteries.
        • Well, if these LiPos last long enough, I get a music player supporting all sorts of audio CDs and a 80 gig hard-disk: Mini-Shuffle!
        • Re:Yes, but (Score:5, Interesting)

          by danigiri (310827) on Wednesday May 18, 2005 @12:13PM (#12567468)
          A lot.

          I am working on a research project that deals with Augmented Reality (basically VR goggles that are see through).

          AR deals with guys that hang around somewhere and use the following simultaneously to do some shit:

          - GPS receiver: to know where one is going and have data referenced following position

          - See-thru goggles that display geographical information (coming from an VGA port)

          - PDA or some sort of input/otput device

          - Wireless: for network stuff and group behaviour

          - Database: some sort of sane data repository that can be updated

          - Bluetooth: problably to connect all these devices together and not strangle the users with cabling

          Yeah, an small/light non-custom-built machine that can deal with all this easily would be great indeed. Oh, and sane developer tools as well.

          Once proof of concept and prototyping is done, someone else will find the funding for embedded custom development.
    • Yes, terrific idea. If only Apple made something like the iMac with a battery already installed. In fact, if they made a portable version of the battery-powered iMac, I'd buy one and finally ditch my Powerbook.
  • Quiet Macs (Score:2, Insightful)

    "Although it runs fine without wires, he had to plug in the monitor to be able to show that it was really up."

    Helps that Macs generally (yes, there are exceptions) run whisper quiet. Is the computer on? With a PC, just listen for the fan noise. With a Mac, hmm..can't tell, better look at the screen.

    • Re:Quiet Macs (Score:2, Interesting)

      by freeplatypus (846535)
      Wake up Neo. This is a dream. This is a big lie!

      If You think that 20dB from the PC case is a lot then maybe You should think it over.
    • Re:Quiet Macs (Score:3, Interesting)

      by clontzman (325677)
      Er... yeah, tell that to the wind tunnels I've had under my desk for the past couple years -- first an MDD, now a G5. Nice, yes, but quiet they ain't.

      PC's engineered to be quiet are quiet. My Dell is nearly silent. Macs engineered to be quiet are also quiet. It has nothing to do with the platform.
      • Re:Quiet Macs (Score:3, Interesting)

        by jrockway (229604)
        We have "silent" MPC computers in one of our computer labs. The silence is a copmromise between noise and melting the processor. Once in a while, we install a gaming image onto these machines... but it's pretty much useless because every single machine crashes solid after about ten minutes of gaming.

        Silent != good.
      • *sigh*

        I specifically wrote " generally (yes, there are exceptions)" to avoid this sort of response, by pre-acknowledging what you later wrote. I'm well aware of the wind tunnel Macs, but they are the exceptions. The iMac -- very quiet. Powerbooks -- silent. iBooks -- silent. Mac mini? I've heard silent too, and in fact that was the whole point of this thread. I was responding to an aspect of the mini in question from the article.

        • My Powerbook sounds like a jet engine is starting up on my lap when it gets too warm. Granted it's an older titanium model and I haven't used any of the new ones, but it's definitely not silent.
          • Well, I'm going off my experience with my Powerbook, and it's silent. I agree that if it gets too warm the fan goes on and the fan is far from silent. But the fan on my Powerbook goes on about once every couple of months, if that.
          • Re:Quiet Macs (Score:2, Informative)

            by admactanium (670209)

            My Powerbook sounds like a jet engine is starting up on my lap when it gets too warm. Granted it's an older titanium model and I haven't used any of the new ones, but it's definitely not silent.

            the older titaniums are definitely louder than the new aluminums. i had a 667 titanium and that thing's fan was on all the time. my 1 Ghz titanium's fan was still pretty active. i have a new 1.67 Al and it's pretty quiet. i have to be doing quite a bit to get the fan running and i've never heard it as loud as my

        • I know what you said, but you can't say that "PCs are loud and Macs are quiet (with some exceptions)" and not expect someone to call your bluff when the "exceptions" are at least half of the product line. My point is that it isn't a platform thing -- there are quiet PCs and there are quiet Macs and loud PCs and loud Macs. All friends here.
          • Fair enough, but it's news to me that half the product line is noisy. Desktop G5s? Fine. But I know of nothing else, although people keep pointing me to research noisy laptops. I acknowledge they exist, but I've never experienced it with three different Apple laptops.

            I never claimed my post was scientific evidence, just my personal experience and what I extrapolated from that personal experience. I certainly understand how someone who had a completely different experience would object, but it just is

      • My Dell is nearly silent.

        I had to use a dell for a while, and it was unnerving. The lack of fan noise I mean.

        I felt a lot better once I got back to a computer I could hear.
    • Re:Quiet Macs (Score:2, Interesting)

      by adam1101 (805240)
      > With a PC, just listen for the fan noise.

      One of the biggest reasons that Mac-PC hardware comparisons are doomed to fail is that there is no such thing as "a PC". Most PCs are loud. But there are many PCs that are quieter than desktop Macs. Many PC laptops are heavy, loud, hot and have short battery lives. But there are PC laptops that are lighter, cooler, quieter (fanless 1.1ghz Pentium-M) and have longer battery lives than any Mac 'Book. Mac fans invariably pick the worst PCs to compare with while PC
    • I can hear my PC only at night, in an entirely silent room, with no traffic noise and no aircon. Then it's a just-noticable whisper from sitting right next to it. With any other sound in the room it's inaudible.

      This is an Athlon XP 3200+ with 3x 200GB Seagate drives and an Nvidia 6600GT. It plays all the games I throw at it just fine, core temp never gets above 50 degrees C. All you need to do is be careful with your cooling solutions (I use a Panaflo case fan, SilenX PSU and Zalman CPU and GPU coolers all
    • My PC is whisper quiet right now

      When I go play games and the fans start to turn on, it sounds like a jet engine.

      Power-up is even better, because *everything* kicks in at once along with the hard disks so it's just plain loud.
    • by mathmatt (851301) on Wednesday May 18, 2005 @11:19AM (#12566853) Homepage
      "Although it runs fine without wires, he had to plug in the monitor to be able to show that it was really up."

      Actually, the mac is both dead and alive until the monitor is plugged in - at which time the mac's probablility wave instantaneously settles in at its definite and final value...that is until the batteries run out, then it's a $500 doorstop.
    • I don't know much about hardware, but I have an HP Vectra VL (according to the label here on the case) that I picked up from the MIT Flea Market. It's a Pentium 1 with all sorts of built-in ports, and I use it as a miscellaneous linux machine.

      It is absolutely silent. I had it running, sitting a shelf right between my desk and my bed, happily waiting for someone to connect, for over fifty days. I lived, ate, and slept with the computer a foot from me. And I never realized it was turned on.

      The blinky l
  • by JawzX (3756) on Wednesday May 18, 2005 @10:01AM (#12566062) Homepage Journal
    VNC is the obvious way to talk to the machine without a monitor connected...

    If an external battery could be housed in a mac mini form factor external case (stacked under/ontop of the mini) I bet battery life could be equivelent or longer than a power-book (no LCD to run). Could provide some interesting low-cost remote monitoring solutions...
    • I can confirm that this will work. I recently set up my Mac Mini so that I can take it with me without having to bring along a keyboard, mouse, or monitor. I just plug in the ethernet cable and power cord and I can control it from my Windows laptop via VNC. The only problem is you are limited to two display resolutions. You might be able to force it into recognizing different resolutions using SwitchResX or having some kind of VGA adapter connected.
  • by Timesprout (579035) on Wednesday May 18, 2005 @10:07AM (#12566134)
    wait till you see my gerbil powered mini. I'm having a small problem with it though, it runs just fine in my test harness but the power seems to tail off and then die shortly after I hermetically seal the case.
  • by Anonymous Coward on Wednesday May 18, 2005 @10:07AM (#12566140)
    The author says he measured 14-20W for the mac mini under load, but his 80W-Hr battery only lasted 1H:50M, implying a 40W+ power draw.

    Am I missing something?
    • Macs do draw that low of power. My powerbook g4 draws at most 28 watts when charging the battery and playing UT 2004 at the same time. (graphics and CPU maxed out) It draws 18 watts under normal use, and 2 watts asleep OR off when not charging batteries.

      Not sure why his unit only lasted 2 hrs though. The author mentioned the computer will run off from 12-20v, and it seems like he had enough cells to keep the voltage up until they wound down all the way. G4 processors are good at conserving energy, and
    • by enosys (705759) on Wednesday May 18, 2005 @11:31AM (#12567006) Homepage
      The author says he measured 14-20W for the mac mini under load, but his 80W-Hr battery only lasted 1H:50M, implying a 40W+ power draw.

      It's not that simple. It's not like the batteries supply 80W-Hr of power at their rated voltage and then shut down. With most types of batteries the voltage drops slowly as they discharge. Batteries also aren't perfect voltage sources. They have internal resistance, which means that if you draw more current the voltage will drop. I suspect the voltage got too low because of these two factors and the Mac Mini crashed or shut down. The batteries might still be able to power a flashlight.

    • Several things:

      The author likely measured average consumption sans peaks. In other words, the multimeter he used does not respond to short huge current demands. Depending on the meter, in fact, and the switching regulator inside the mini he may have a very bad reading. This kind of measurement is difficult to take accurately without equipment meant to measure this - one which integrates the current consumption over time, including peaks, for instance.

      The cells are rated for 4AH, but there's no guar
  • by dave_mcmillen (250780) * on Wednesday May 18, 2005 @10:08AM (#12566152)
    Hey, this could be the start of something big! What if he were to also install a portable screen? Maybe it could, I dunno, fold down into the top of the machine, or something. Then you could carry the computer around and do stuff with it, wherever you went, while resting it on your knee. A sort of "knee-top" compiter, though maybe there's a better name someone can think of . . .
    • by nine-times (778537) <nine.times@gmail.com> on Wednesday May 18, 2005 @10:31AM (#12566402) Homepage
      Bah... and what are you going to do for input? You can install a screen, but then you'd still have to carry around a keyboard and mouse. What, you're going to attach a keyboard and mouse to this whole setup? It's patently absurd.
    • ..Or maybe someone could make the Mac Mini even smaller, something that could sit on the "top" of your "palm". What kind of computer would they call that?

      Here's the basic idea. You have several product lines: desktops, laptops, palm tops. Each line has a top of the market, and a bottom that provide the most and least features within that line, respectively. I think what we're seeing here is an instance of a phenomenon where the bottom of one product line can come into the neighborhood of the top of ano
  • Darwin award soon (Score:5, Informative)

    by ballpoint (192660) on Wednesday May 18, 2005 @10:08AM (#12566162)
    Exactly how is the LiPo battery charged ?

    Without a proper charger, combining the energy density of a 80Wh battery with highly reactive Lithium is a recipe for disaster.

    http://www.rcgroups.com/forums/showthread.php?t=20 9187 [rcgroups.com]
    • From TFA:

      The second thing I wanted to mention, and this is IMPORTANT, these cells don't have a current regulator on them. So when you recharge them, do not use the Mac's power cord. Instead use a power supply which has a current limiting knob on it so that you can keep the current low whilst charging the batteries. Don't blame me if you plug in your Mac's power cable and it fries your power supply.

      and:

      TODO:
      Include a current regulator so that the battery can be charged from the power cable.

      • Re:Darwin award soon (Score:4, Informative)

        by ballpoint (192660) on Wednesday May 18, 2005 @10:49AM (#12566591)
        A simple power supply with a current limiting knob isn't safe. Overcharge a LiPo and you'll set it on fire in a rather spectacular and difficult to extinguish way.

        A charger that is specifically designed for LiPo charging is a MUST.
        • I admit not knowing much about Lithium-Ion Polymer batteries. If this is the case, you might want to bring it to the attention of the author. The story was submited as an AC, but there's an email address on the website, spamproofed:
          silasb_at_earthlink.net

          Unless you enjoy knowing that people have caught on fire from their own ignorance, it would be a good idea to write an email explaining the problem and why.

  • 12W (Score:5, Informative)

    by IceFox (18179) on Wednesday May 18, 2005 @10:09AM (#12566168) Homepage
    Wow, at only 12W for the entire system? It is pretty hard to get a x86 box that low for that
    cheap.

    -Benjamin Meyer
  • Article Text (Score:5, Informative)

    by riffzifnab (449869) on Wednesday May 18, 2005 @10:15AM (#12566236) Journal
    Mac Mini Surgery

    I had an itch to scratch so here it is...

    Earlier this week I read an article on the Debian Weekly News, about a Debian box running on 3 Watts, and it reminded me of a project that I was asked to put on the shelf some time ago. The gist of the article linked to by the DWN was that Alex Perry got to wondering how much power his Linksys switch was sucking down whilst running 24/7, and found that his Manga, an ARM based router box, not only consumed less power but was able to run full blown Debian to boot. His point was "If I am going to pay to have a switch run 24/7, I might as well have the switch be a useful server as well." Following his article the PepLink community promptly got X11 working on the Manga and Alex's website was updated with the screen shots, which I might add are quite amusing.

    While I do sympathize with the original thrust of the article, I must say that the Manga's ARM is a rather diminutive processor for a desktop machine these days. So my question is why would you run a Manga as a desktop to get down to the 3 Watt mark when for just a few more Watts you can run a box with a G4 processor? Yes, I am talking about that little machine that all of my geek friends (me included) seem to be drooling over as of late. The Mac Mini!

    Several months ago I was in need of finding a small but powerful computer that could be run for a long period of time on batteries and not be a burden to carry. I was looking at several embedded options from places like kontron and mini-box, when I saw an article on the Mac Mini. Looking at the limited specs for the Mac Mini on Apple's website I began to suspect that if I removed the cdrom drive I would be able to fit a "lithium-ion polymer" battery pack inside the vacated space. I say that I suspected this because Apple is lousy about posting specs about internals and stuff that your Grandparents wouldn't normally ask about. So I ran down to the local Apple store with my trusty calipers and had one of their technicians go into the back and measure the dimensions of the cdrom drive for me. The numbers that he gave me made my day, the batteries would fit! Now about power specs. Apple of course did not have the DC power specs online, and nobody I talked to at the Apple store or on the support line could get them for me. In an act of desperation I resorted to sending email to combinations of addresses like steve_at_apple.com sjobs_at_apple.com, steve.jobs_at_apple.com, etc asking for the specs. Funny enough I got a reply (No, not from Steve Jobs) from an Engineer who was quite helpful. It looked like the Mac could do it, so I decided to get one and hack on it. The Mac was dirt cheap compared to the embedded systems so it was a very limited risk approach to proceeding on the project.

    I ordered the Mac, a 4GB Hitachi Microdrive, and a laptop-IDE to CF adapter. I also talked to Mike (Dr. Zhang) at SKC PowerTech, Inc, and he was kind enough to send me some batteries for evaluation. The batteries were a new design and were not yet in production, so there was a bit of a lead time on those, but at the end of two days I had the rest of the necessities at hand. First things first, I measured the out of the box power draw of the Mac Mini, which turned out to be only 12 Watts! This was better than the specs I was given. I then proceeded to remove the hard disk and replace it with the Microdrive-CF adapter setup. Then I got me a Debian (Sarge) disk *GRIN*. This was the first time I had touched a Mac, and I was pleased to find that the Debian install on the Mac was smooth and painless. After getting the system up and running, I did some stress testing on it. The testing involved running simultaneous FFT routines (like 30 of them) on 80MB data files. The system was so heavily loaded that it took about 15 minutes to log into the machine from another terminal, and another 15 minutes to get to the bash prompt. During this utter thrashing of the system the highest the power usage spiked to was 20 Watts, but it stayed around 14
  • So, could they not just connect to the thing over a WLAN? I suppose, they couldn't verify that it was that specific mini...
  • He says that he used two wires for each power connection to ensure that it could carry enough current. Does this actually work? Doesn't electricity take the shortest path thus overloading the wire with the least resistance?
  • It looks like a nice hack... But what would be really cool, was if you somehow could get the power from the monitor.
  • buy a laptop....iBook....

    ???????
  • by WormholeFiend (674934) on Wednesday May 18, 2005 @10:25AM (#12566332)
    for an Apple computer that runs on human blood [slashdot.org]!

    Oh wait...
  • It's also (Score:2, Insightful)

    by chadseld (761331)
    sans optical drive.
  • by gadgetbox (872707) on Wednesday May 18, 2005 @10:39AM (#12566490)
    Seriously, give the guy a break. This mod probably wasn't as easy as it looks. Yes, it does have a very limited practical application due to the fact that you need a powered monitor (network access aside), but....in the long run, things like this can serve up some very innovative creations. Perhaps someone else will see this, and take it a step further, and eventually some ingenious application for a battery powered Mac Mini will appear. I say bravo, good job, and keep on tinkering.
  • I'm curious, does the linux kernel have processor cycling for PPC (Mac) computers? The reason I ask is that the computer may run longer with OS X if the linux kernel keeps the processor consuming power at a standard rate. The OS X kernel cycles the processor during idle periods to consume less power.

    Perhaps I'm off base and this is handled on the motherboard?
  • with a screen, on the LAN.

    You could always VPN into it, like my friend who leaves stuff running on his box when he comes over from his place in the Bronx to my place in Jersey City.

    That's how he checks the status of his box.

  • Server batteries (Score:3, Interesting)

    by scrotch (605605) on Wednesday May 18, 2005 @11:08AM (#12566762)

    I've often wondered why there aren't servers with batteries built in for a few minutes of power after the UPS goes down.

    Apple could get especially good results from doing this because of their hardware-software integration. Imagine an xserve with ten minutes of battery power built in. Can't you see the interface where you have the computer run a script that emails you after it's been on battery power for two minutes? Imagine hooks for when battery power starts to be used, and when a clean, painless shutdown begins, or when power is restored before the battery runs out.

    This would be of great value to me anyway. I know some UPS software offers this (though I'm not sure what the state of Mac-compatibility is), but Apple could surely do a better, more thorough job.
    • by drinkypoo (153816) <martin.espinoza@gmail.com> on Wednesday May 18, 2005 @11:55AM (#12567271) Homepage Journal

      I've often wondered why there aren't servers with batteries built in for a few minutes of power after the UPS goes down.

      spend less time wondering and more time doing research. Some of IBM's AS/400 systems (whatever-series, now) have a built-in UPS; they are sold as a complete computing solution for businesses. Just plug it in, and compute.

      Or, you know, you could try a google search [fuckinggoogleit.com], if that's not too much trouble.

    • have the computer run a script that emails you after it's been on battery power for two minutes?

      You'll get you're email about a minute after the power (and therefore the network) comes back on! Although this has been done with systems that have modems attached for dial out notification.

  • OK, it's cute to fit it inside the case, but if you could get a UPS that'd stack under the Mini with a compatible power connector you could get almost all the convenience (and, let's face it, "mini chic") with a lot less complexity.

    They'd probably need to coordinate with Apple on the power, but it'd make the standby a lot more efficient than if they did the usual DC->AC->DC thing, and they already do DC UPSes for racks.
  • Does the Mac mini have an inertial sensor like the PowerBooks?

    If so, is it accurate enough that I use one of these modded Mac minis as a guidance system for an intercontinental ballistic missile?
  • ...iPod for n3rds.

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