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Handhelds Hardware

Perpetual PDA Power? Possibly. 59

Posted by michael from the poetry-potpourri dept.
robb_c sent us this story about new high-efficiency power systems for portable devices - high-efficiency solar cells plus some sort of fuel cell system to store energy. Very nice, if it works, doesn't cost some ludicrous amount to manufacture, and doesn't explode when you drop it.
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Perpetual PDA Power? Possibly. More

Perpetual PDA Power? Possibly.

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  • I've taken my Palm V on vacation or a week and never had the battery go dead on me. When I got back to the office I just stuck it in the cradle to hotsync, picked it up a bit later to take to a meeting and it was all charged up. The only place this would be useful is in power hungry PDAs that suck (energy) more than the Palm stuff like WinCE machines.

  • This is a wind-up (Score:4)

    by PhilHibbs ( 4537 ) <snarks@gmail.com> on Thursday April 19, 2001 @01:02AM (#280797) Journal
    I want a clockwork PDA! You can already get clockwork radios and flashlights, why not a computer?
  • There's already a solar mod [fureai.or.jp] for the Palms on the Japanese site "Palm de Cool [fureai.or.jp]". The electrical connection between the lid and the Palm is particularly cool.

    --

  • Come on now, live a little!!! It'll make those Friday afternoon team meetings go by quicker; if all the techs are carrying one... (Would that make a Beowulf cluster?)

    make that Beowulf cluster bombs
    thank you, and goodnight...
    ---
  • > Nice idea but once your holding your PAD and you have the screen on the front where do you put
    > the cells?

    Ah, but you forgot about the OTHER gadgets they presented at the same show. There's the solar cell sunshades with the directional antenna that constantly gets pointed at your PDA/cell phone and transmits the electricity as a focused microwave beam. Or, for the less fashion conscious and more power hungry, there's the solar cell helmet. It doubles as a motorcycle helmet and is completely coated with solar cells. It also features the same directional antenna as the shades.
  • One example is the Seiko kinetic series of watches.

    These have a tiny rotational generator inside which charge up a capacitor which is then used to power the watch during periods of no movement.

    The generator can actually be heard if you move the watch near to your ear. I believe that the counterweight's movement is geared up by a very high ratio before the generator mechanism (in fact in the manual it quotes some statistic or other about the generator's rotational speed versus rpm of an F1 engine or similar...)

    It only takes a short time of normal wearing before the capacitor is fully charged.
    --

  • I keep on reading about them, but don't people
    selling devices based on them.
  • The risks of explosion from fuel cell batteries is probably smaller than the risk that your Lithium-ion battery explodes.

    I think there must be some sort of deep correlative link between being a Slashdotter and either (a) thinking that fuel cells are likely to explode and/or (b) exaggerating the explosive risk for "humor" value.

    On the other hand, this may point out a potential PR issue for fuel cell makers. If even (supposedly) intelligent people like geeks make this kind of mistake, what will be the reaction of the general public?

  • Very nice, if it works, doesn't cost some ludicrous amount to manufacture, and doesn't explode when you drop it

    Yeah...that federal building in Oklahoma City wasn't an ANFOS...it was a guy who dropped an early fuel cell PDA! :)

    Actually, the other limitation would be SIZE...nobody wants a PDA that weighs 300 pounds, etiher. :) (Shut up all you body builders! :)
  • Okay, it'll never happen, but here's a thought.

    They've got fuel cells that will generate electricity from most types of natural gases.

    What would happen if you hooked one of those into your pda, and your PDA via a long tube to the methane generating portions of your body?

    Okay, it's stupid but what about as a source of energy for wearable computers? Your wearable PC could be powered by your underwear energy harness!
  • ...Kinetic power? like the watches that derive power from the movement when you're walking along and whatnot?

    I know it wouldn't be feasible for something like an ipaq, but surely it could extend the life of the battery on low-power devices like the palms?


    --Gfunk
  • I'm wondering the same thing. The fuel cell runs on fuel. I believe 2H+O -> H20 is the goal. I didn't see any explanation of how to feed more hydrogen to the fuel cell by using solar cells.

    I suppose you could use the solar cell electricity to electrolyze water into Hydrogen and Oxygen, but why didn't someone say that?

  • The risks of explosion from fuel cell batteries is probably smaller than the risk that your Lithium-ion battery explodes.

    Most fuel cell technology uses substances like methanol as a fuel, and this is pretty harmless stuff.

    Lithium-ion batteries can potentially create metallic Lithium, and that would be a bad thing to have sprayed all over your lap. Try looking up 'lithium ion explosion' on google [google.com]
  • what the photon density of sunlight is in my pocket?

    They've had solar powered calculators for year, but a PDA would seem to use quite a bit more power. I would assume that the PDA would charge a battery that would work for peak usage. Unfortunately, how do I get a charge with the thing in my pocket?

  • Hmmmm (Score:1)

    by Cyn ( 50070 )
    and doesn't explode when you drop it

    That'd be pretty cool. I've had my palm for like 6 months now, and have yet to drop it - so for all I know, it could explode when I drop it... in which case it wouldn't matter too much if the fuel cells did too.

    Come to think, if they're not too expensive - it'd probably be a Bad Thing (tm) if they do explode when dropped - kids buying them by the dozen and having a go on the night before halloween.

    Seriously though, I don't know - my palm works great off rechargable alkalines, don't really have many problems - batteries last easily 2 weeks (heavy use) but I change them out after 1 1/2 since alkalines last longer if not fully drained before recharged.
  • How about methane gas powered PDA's. This would work really well in areas where there are lots of cows.

    Think about how agricultural this idea is, and I'm sure you won't disagree
  • Sounds great. I'll just try to remember not to put my PDA in my front pocket, near my testicles.

    ... sorry, I have no idea what a thin-layer isotopic whatchawhosis even is, and I'm sure it's nontoxic, non-lethally radioactive, water-soluble, lowfat, organic, and comes with a touch of motherly love in every drop. And I'll buy anything that could power my Mindstorms for 30 years at a time no matter how much cancer it gives me, so hey, I'm not saying I'm against it. So what is this thing you speak of?
  • Huh. Sounds pretty cool, actually. Thanks!
  • This is an excellent idea. Any PDA that's actually being used is pretty much always on the "move." Kinetic power would be a great way to charge the batteries while you're off the cradle/power supply.
  • doesn't explode when you drop it.

    Come on now, live a little!!! It'll make those Friday afternoon team meetings go by quicker; if all the techs are carrying one... (Would that make a Beowulf cluster?)

    Strong data typing is for those with weak minds.

  • Solar works fine in England, even when travelling by boat [futureenergies.com] or car [futureenergies.com]. Cloud cover cuts off far less solar power than you might imagine.

    Phillip.
  • A clockwork PDA was already done.

    Newton E-mates had such added. Given they draw 57mA at 7 volts when active (no ethernet or backlighting), you can power them with the windup section from a freeplay radio. link [yahoo.com]

  • How Stuff Works has a some information [howstuffworks.com] on how self-winding watches work. From the article, the amount of energy generated would seem to be enough to keep the watch running plus a little more-- "enough energy to keep the watch going for about a day and a half if you leave it on your dresser".

    I wonder how this sort of level of power is comparable to the triple-As in my Palm...

  • Well, if you don't have sunlight available, I think you can probably use batteries... Just a thought. It would be useful for 90% of the PDA using world, no doubt.
  • On the other hand, the general public knows very little about fuel cells and do not automatically associate it with hydrogen, methanol and other flamable substances. :-)

  • Will my laptop come with a free radiation suit? =-)

  • Using petrol at first is a good thing because it allows for a gradual switchover. That this switchover will come is inevitable, and sooner than people would like to believe (the petrol reserves may last for over 100 years, but they will become difficult and expensive to exploit long before that). That the petrol companies are taking over that business is a smart move for both them and the consumer because it means continuity.

  • Well, exploding when dropped would be a security feature for those really paranoid clients. "Don't make me drop this thing!" :-)


    --
    News for geeks in Austin: www.geekaustin.org [geekaustin.org]
  • Silly slashdot story simply stated: storing some sort of small cell system sucks. Damn...It's too early in the morning for this.
  • Explode when dropped is nothing -- I keep my PDA in my pants pocket. I don't want any weird radiation... well, you know.

    A colleague of mine was talking about his cell phone. We asked him if he was concerned about eye cancer. He informed us that he keeps his cell phone clipped to his belt and uses a handset, so he didn't have to worry about cancer. We smiled and nodded.

  • Actually someone tried this with an apple laptop once. The powerbook 1400 had a little removable hinged compartment on the back of the screen. One company made a small solar cell that could be attached in place of the plastic door. IIRC, it worked pretty well at extending battery life, but was bulky, heavy, and expensive. As for getting energy back from the screen, using a mirror and a smaller backlight would be more efficient, lighter, and cheaper.
  • Read the article, it says that office lighting is 3x brighter than is needed by it.... Of course they could be making it up as they go along....
  • Hydrolysis is an expensive way to generate hydrogen.

    If you remember your chemistry, you'll recall a term called "activation energy." Activation Energy refers to the excess power needed for a reaction to take place and for hydrolysis, it's pretty high.

  • More Bong hits, no doubt. (Score:3)

    by Glowing Fish ( 155236 ) on Thursday April 19, 2001 @01:23AM (#280829) Homepage
    (Gurgling)

    Dude, have you ever thought about how wasteful batteries are? Like, why don't we like, build a PDA that runs on Solar Power? Because, like, its natural dude!

    (Gurgling)

    You know what would be even cooler? If you could, like, have a button on the PDA that would order a pizza to your door any time, day or night!

    (Gurgling)

    Dude, munchies over FTP would be 31337!!! If only I could remember my password...

    Dude, you know what would be the coolest thing ever! If you could make a PDA into a BONG!!!

    Yeah, and we could run the whole thing off a nine volt battery!!!

  • LIke I mentioned, this was 13/14 yr old stuff.

    But there are other ways of making a sustainable system... that have been discussed here on /. and elsewhere.

    You can build a 2-step fuel cell (terminology?)/

    • Input methanol
    • step 1: Methanol --catalysis--> H2 + O2
    • step 2: 2H2 + O2 --catalysis--> 2H2O + electricity

      • But there are so many ways of storing energy when it's plentiful, so you can liberate it later as electricity...

        For example (a bit off topic, this is region-scale, not laptop-scale) use wind or tidal power to move water up behind a dam. Then later, when you need more electricity, release the water through turbines.

  • As I understand it, the fuel-cell does this:

    • 2H2 + O2 --catalysis--> 2H2O while generating electricity

    Now, if you want to use a solar cell to generate some electricity, you can run the reaction backwards, electrolysing the water thus:

    • 2H20 --electrolysis--> 2H2 + 02 while consuming electricity

    The point being, that you need to store the O2 and H2 given off by electrolysis, so you can use it later for the catalytic reaction.

    This stuff was taught in chemistry and physics when I was 13 - 14 yrs old.

  • I can't speak for anyone else, but any power source dependent on me going outside and getting some sun isn't going to be much help.

  • So that thing Dilbert and Wally gave the PHB (long gone from the archives by now, anyone saved it?) was ACTUALLY a notebook?
  • Actually, if you are projecting light in both directions, I would think it would be more efficient to simply reflect that light back out to the user with a high quality mirror, and cut down on the power used in the first place to illuminate the screen.

  • Wrist Watches? (Score:3)

    by SlashGeek ( 192010 ) <petebibbyjr@@@gmail...com> on Thursday April 19, 2001 @01:10AM (#280835)
    I believe some wristwatch have something possibly useful for PDA's. It didn't occur to me until just now, but there are wrist watches that charge as you walk. As far as I know they contain a pendulim attached to a small generator. As you walk and swing your arms, the watch charges a batter, or winds a spring, or charges a capacitor, or something. Now few of us wear PDA's on a location like a wrist, with high movement during normal walking. Movement in a shirt or jacket pocket would be limited. But how about a small wrist mounted deivce? Or ankle mounted? Ok, so mabey having wires running all over your body isn't the most practical idea, but it still could save some normally wasted energy.

  • What about throwing these in laptops? If you could throw one of these into the shell right behind the screen, you could possibly get the added benefit of getting a little extra energy off the screen (kinda like a hybrid car generating a little energy off the rotational energy it already has put into its wheels). Also, would it be possible to use these reversible fuel cells as a replacement for current Li-Ion batteries?
  • I keep my palm in my pocket...does this mean I'd have to wear it, or a solar cell, somewhere on my clothes, or around my neck as a necklace? Seems to me that AAA batteries are easier/more convenient.

    . . .

  • Issue ? (Score:3)

    by mirko ( 198274 ) on Thursday April 19, 2001 @03:14AM (#280838) Journal
    This comment [slashdot.org] is insightful though it deals with kinda extreme situations...
    Anyway, I'd like ot know how long the PDA accumulator could last as, for example, if I backlight my Palm III, this means:
    • I can't actually get the photons I'd need to powerup my device
    • It really becomes power-hungry
    So, are these perpetually loaded PDA only for normal guys working in temperate zone during the day or using a lamp ?
    Hmmm...
    --
  • ...and doesn't explode when you drop it.

    Or when a sniper shoots it with a bullet, killing all soldiers within a square kilometer of you!

    Aw shit, we already discussed this [slashdot.org]!
    Still could be a factor, because those cell phone batteries are so big, and you'd (gasp) have to spend sometime letting it absorb light - I don't think your monitor quite has the luminence for the job. What I really want is a cell phone powered like one of those watches: by the motion of my body.

    Kurdt
  • Skip solar, it has too many constraints about how much light and when, not to mention that making the cell might produce more pollution than it saves during its lifetime.

    Fuel cells are nice, but they have to have air, you can't use them in a rated space, and the fuel runs out. True, you can get more, but then you just have a longer running version of the AAA cell.

    I want PDAs to come with a thin-layer isotopic battery built in, that never needs to be changed during the lifetime (oh, say thirty years) of the computer. Save wear, tear, grief all the way around, no more annoying battery doors to pop off at unsuspecting moments, decent reliability, and it gives us a reason to dig out some of the nuke waste that we've been hording and get it usefully distributed around the world.

  • There are two types that I have found:

    The first uses a radioactive isotope spread on one side of a set of Peltier juntctions. The other side is left at ambient. Radioactivity is absorbed by the junction mass, turns into heat, which in turn creates voltage across device. Descendants of the SNAP generators. This might not be so practical for a PDA, but might fit in a laptop.

    Second, silicon-based photoelectric cells react to particle radiation in much the same way as light. Small printed patterns of ink containing radioactive material are laid down on silicon cells, which are then stacked to give needed voltage and power. There was also some talk of using amorphous solar cell material, which is flexible, putting the radioactives on a strip near one end, and then rolling the thing up in order to get it into a smaller box with less labor. I believe E.F. Johnson holds patent on some of this.

    It has been years since I looked into this, I don't know if anybody is mass-producing these critters or not. Round up the usual mil-spec hardware vendors.

  • I bought the original Palm Pilot when they first came out. It ran on a couple of bateries and that was it...
    You had to keep an eye on the battery power and then quickly change them. I believe you had a whole minute to change the batteries or else all data would be lost.
    Talk about being a slave to your PDA
    The new ones now recharge when they're in the cradle but sometimes I like to be on the go and don't need to sync up for a while. It would be nice to know that I wouldn't have to worry about my PDA's power supply!

    If solar can work, it will be a cheap and easy way to replenish the batteries.. heck even those of you in the cubical farms will have enough light to recharge them!

    Linuxrunner
  • ... how many geeks do ever see sunlight?

  • I am sure most Palms see the sun even less than their owners...

    Now if they can come up with something that generates power from body heats and salt water, the by-products of sweaty palms, it will be a nice environmentally sounds renewable source of energy for all your geek toys.

    Patent pending...

    ====

  • Ministry of Health [moh.govt.nz] warning: usage could blow you apart if you drop it more than 15cm. But seeing you'll want to use it in a PDA, go right ahead... ;)

    Oops, bad humour sorry. :(

  • A cool super-power,
    "STAND BACK", "Or i Will drop my PDA!"
  • I thought it was generally a BAD idea to drop small electronic devices with fragile screens. Then again if it did explode when hit against something hard...Hand Grenades.whoa.

    Arathres


    I love my iBook. I use it to run Linux!
  • a small, thin wedge that I can put in my shoes to generate power with every step! As much as I weigh, I could supply power for most of California!
  • Next thing you know they'll have LCD clocks powered by potatos.

    I'm wondering if it would be possible to make a supplimentary power source that would use a peltier cooler to create power from the body heat generated by your hand holding the device. How much current can be created by one of those gizmos?

  • That is exacly what I thought. And when i'm not using it, it is tuffed away in its nice leather cover: no light.

    Then for my mobile phone: I usually attach it on my belt. There it hangs _under_ the pull-over I wear: no light.
    When i'm using it, one half is covered bu my hand, and the other half is against my cheek: no light.

    A recent law obliges me to use a hands free system if i want to make calls while driving a car: light, but the car kit also charges my battery, so I don't need light...

    Whats wrong with plugging your PDA or phone in at night?

    Conclusion: nice work guys but rather useless for some (most?) of us.

    I also doubt that the >20% efficiency remains once the cells get covered in fingerprints and dust.

    That gas cell on the other hand seem more interesting, but is it really safe? Can I bring it on board a plane?

  • How heavy are these systems? I know a regular laptop battery is heavy but it can't be nearly as heavy as these things! A really big pus in laptops is for the lighter/smaller laptops. If this ads a extra 3-4lb or higher of weight will people still want to buy it?
  • I didn't see any explanation of how to feed more hydrogen to the fuel cell by using solar cells.
    Chalk up another win for the "science is irrelevant" school of journalism...

    If you use a proton-exchange membrane fuel cell, the water will pile up at the oxygen electrode. Using a membrane like silicone you can hold the water but let oxygen diffuse in and out. Running the fuel cell backwards, at the oxygen electrode you have the reaction:

    2 H2O -> 4H+ + O2 + 4e-

    The hydrogen electrode has the reaction:

    4H+ + 4e- -> 2H2

    You can stuff the H2 right back into your storage, which could be a metal-hydride unit right out of a NiMH battery. Voila, you've gotten rid of the nickel electrode and all its weight, substituting air (and the bit of water you keep to regenerate the H2).
    --
    spam spam spam spam spam spam
    No one expects the Spammish Repetition!

  • I'm moving back to England. No solar power for me :-(
    --
  • The battery on my Nokia 8290 is the only thing keeping it from becoming a choking hazard to small children. =)

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