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The Next Notebook Battery? Lithium Polymer 124

Posted by Zonk
from the better-than-a-burning-notebook-in-your-lap dept.
Lewis Clarke writes "Sony is changing its course to use an old technology for its new battery manufacturing. ZDNet is reporting on comments from Sony Electronics President Stan Glasgow, where he said that Notebook makers will 'likely' soon choose to incorporate lithium polymer batteries (a battery technology that emerged nine years ago) over the current commonly used type, lithium ion batteries." From the article: "Lithium polymer batteries use lithium as an active ingredient. Lithium is a volatile material, but the lithium in these batteries isn't packed into cells as it is in lithium ion batteries. Instead, it is contained in a polymer gel. These gel batteries can't provide the same sort of energy density as lithium ion batteries, but that's now a plus."
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The Next Notebook Battery? Lithium Polymer

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  • I must be getting confused - I thought Lithium Polymer was better than Lithium Ion?

    Or, giving them their full name, are they not referring to Lithium Ion Polymer batteries?
    • Re:Eh? (Score:5, Informative)

      by arth1 (260657) on Friday December 08, 2006 @12:49PM (#17163514) Homepage Journal
      I must be getting confused - I thought Lithium Polymer was better than Lithium Ion?

      In some ways. It's the same thing, really, but packaged two different ways. Both are often called Li-Ion batteries, cause they are. The main two advantages of Lithium Polymer are:
      (A) They can be shaped in all kinds of odd shapes, which is a benefit when you also pack some circuitry inside the battery package, or have to use space as best you can.
      (B) They are less likely to explode, as there's resistance in the gel medium itself that hinders (if not completely prevents) a chain reaction.

      The main downside to Li-Polymer is that it is less efficient by volume and weight.

      Regards,
      --
      *Art
      • NOT TRUE (Score:5, Interesting)

        by IflyRC (956454) on Friday December 08, 2006 @01:03PM (#17163702)
        Actually Lipo are more likely to explode. Most Lipo battery cells contain plastic whereas lithium ion cells are metal.

        Lipo battery warning for R/C aviation [wattflyer.com]

        I use both battery types in various aircraft. The lithium polymer is much less stable. I've seen a pack swell and be ready to vent just by knocking one off of a table onto the ground. Lithium ion will not do this. Also, keep in mind that any battery will explode if you overcharge it.
        • Re: (Score:2, Insightful)

          by Anonymous Coward
          Actually Lipo are more likely to explode.

          No, not explode. They just pop and burn. There isn't a metal can holding them together than can explode. That's the difference people are talking about.
          • Re:NOT TRUE (Score:5, Informative)

            by IflyRC (956454) on Friday December 08, 2006 @02:03PM (#17164520)
            True, its not a forceful explosion but the flames are so intense it wouldn't really matter (without the danger of shrapnel). NiMH and Nicad can explode as well but it takes a lot to get them to that point - usually overcharging. Lipos can go just from being dropped.

            How many laptops do you see being dropped? Apparently there is enough lap top dropping that IBM was advertising how sturdy their laptops were a few years back.
            • by treeves (963993)
              Never seen one dropped, but I've seen one closed with a pen lying on top of the keyboard. Cracked the display diagonally on an almost brand new ThinkPad. Ugh.
              • by laffer1 (701823)
                I've seen a laptop get thrown across the room out of anger in my old job. (tech support at a university) That woman had a PHD, but she couldn't figure out that laptops break when they hit the ground. Dell didn't cover that. This was a new laptop as her last one had a large cup of coffee dropped on it. Dell did replace the keyboard and motherboard and we cleaned it up. She refused to use it though. I guess she didn't like the smell of starbucks after all. Don't worry, she was fired eventually.

                More re
        • Re: (Score:3, Funny)

          by knipknap (769880)
          Actually Lipo are more likely to explode.

          If the laptop owner has a chance of survival Sony might have to replace the device. With LiPo batteries, the number of reclaims could be greatly reduced.
        • by shlashdot (689477)
          Seems to me that if you are searching for energy density, the only way to safety is intelligent partitioning. I forsee what I call a "quantum battery" with logic being an integral part of the battery, allowing management of discreet, small packets.
      • The main downside to Li-Polymer is that it is less efficient by volume and weight.

        This, I think, is not true. LiIons may be more efficient by volume, but LiPos are almost certainly more efficient per weight, because they don't have the cells, or many of the protection mechanisms that LiIon batteries have to have.

        The power/weight advantage is why they're used in applications where weight is more important than volume -- R/C aircraft, for instance. When LiPo batteries came out, they basically replaced NiCads and LiIon batteries overnight in most ultralight aircraft and helis, because they're just so much lighter (meaning that if you had an aircraft designed for NiCads, which wasn't atypical, you could get ridiculous flight time by upgrading to LiPoly cells).

        But being more efficient per volume, that I could definitely believe.

        The other big advantage I have heard is that with LiPo, you don't have to encase the batteries as heavily, so more of the weight and volume can actually be taken up with electricity-storing components, instead of as an 'exoskeleton' providing protection for the cells.
        • The other big advantage I have heard is that with LiPo, you don't have to encase the batteries as heavily, so more of the weight and volume can actually be taken up with electricity-storing components, instead of as an 'exoskeleton' providing protection for the cells.

          I'd imagine this has a lot to do with how the manufacturer decides to package the cells.

          My room mate has a few electric RC helicopters and he swapped out the NiMH cells that came with them for bare cell LiPos. They were large flat cells reminis

          • by araemo (603185) on Friday December 08, 2006 @03:18PM (#17165590)
            The advantage to custom designed LiPoly batteries is that you can pack them into tons of nooks and crannies. The thing that still amazes me about your average laptop is that inside that fancy plastic battery pack is a row of cylindrical batteries with air around them. Lipoly fills in all that air with one solid mass of battery, so while the literal energy storing material may be less volume efficient, you can make more efficient use of volume in your designs as opposed to standard LiIon.
        • Re: (Score:3, Informative)

          by sporkme (983186) *
          Most laptop battery packs are comprised of lithium ion cell #18650. They are 3.6 volts (some denote them as 3.7 volts) each cell and are typically around 2200 mAH (2.2 Ampre-Hours). They are arranged in series-parallel to achieve the desired voltage (~14.4 volts) and capacity (~4400mAH).

          Lithium polymer offers a lighter package at a higher volume to achieve the same capacity and discharge current. Because of the high resistance characteristics of the polymer-only substrate, some liquid electrolyte (the
          • by dougmc (70836)
            At least we aren't hauling around giant sealed lead acid batteries (like in a UPS or alarm system) everywhere.
            You know, I *do* have a laptop with a gel cell battery in it. It's a Tandy 8086 I think. :)

            (It's currently sitting as a dumb terminal on a headless SGI. MSDOS boots up to ckermit ...)

    • So now we're going to have to expect an hour and a half of battery life instead of the now standard three and a half hour. . .

      I don't know about anyone else, but I think i'd risk MORE explosive batteries if I could get like 9 hours of juice on my notebook.
      • by zogger (617870)
        ...if you as a consumer would indicate to the vendors that long range battery life is more important than over-all laptop or cellphone lightness. Are you willing to carry an extra pound or two in weight with your laptop? You can have (potentially) a bigger battery, that might be made better-more rugged-so that it is safer plus has good range. Consumers demand the lightest though (I call it the wimpification of society factor), so the vendors are stuck trying to accomodate that. Let the vendors know, startin
        • Cell phones seem to go through phases. Remember when everyone was amazed at how small Japan's cell phones were, and so the US/European companies tried to catch up with that? Right now in Japan I can't find a cell phone smaller than the Razr. They've got ridiculous amounts of features and the things are huge by comparison to US cell phones.

          So it'll probably bounce back.
    • All of Apples MacBooks and MacBook Pros have used LiPo since their debut in January. That's why battery life was uncertain, because LiPo had not been used in notebooks before. I hear they are supposed to be better than LiIon.
  • by value_added (719364) on Friday December 08, 2006 @12:40PM (#17163352)
    Why not use dilithium [wikipedia.org], instead?
    • Re: (Score:3, Funny)

      by Anonymous Coward

      Why not use dilithium [wikipedia.org], instead?
      because it's fictional, you trektard
    • by JabberWokky (19442) <slashdot.com@timewarp.org> on Friday December 08, 2006 @12:46PM (#17163466) Homepage Journal
      Hell, skip that and go straight to trilithium [memory-alpha.org]. If it's good enough for Romulan weaponry, it's good enough to power my laptop... which is placed on my lap... right over my genitals...

      Okay, maybe we should rethink this whole battery thing and go back to luggables.

      --
      Evan

    • by tehwebguy (860335)
      dilithium? might as well be NiMH

      now if you want some REAL power you need Energon [wikipedia.org]
      • by bigred85 (1030936)
        Man, screw Energon.
        I think we ought to skip that stage and go right to having Leadership Matrices installed.
        Imagine, one minute you're working with an old Dell notebook (provided it hasn't exploded in the first place), and after installation
        you see it transformed into Inspiroptimus Prime! Crap, now watch this get modded "Flamebait" for the Dell example.
    • Didn't you hear that everyone has switched over to gel packs?
    • Re: (Score:3, Funny)

      "Why not use dilithium, instead?"

      Because Klingons flooded the market with substandard crystals. Damn near caused humpbacks to go extinct.
    • Dilithium is just a catalyst for the matter/antimatter reaction. You would still need a supply of matter, and antimatter, and containment, which would add way too much to the weight for your puny earth laptop.

      In TNG, all their hand-held and portable devices use Sarium-Krellide power cells.
      • by jandrese (485)
        I thought the Dilithium was not so much a catalyst as a moderator. Generally you don't need to do much to cause matter/antimatter combinations to react once they touch, the trick was not having the energy release blow the matter (and more importantly antimatter) streams against the walls of the engine.
        • by nuzak (959558)
          > I thought the Dilithium was not so much a catalyst as a moderator.

          It's gas. The ship was constantly running out of gas, and they had to find some way to get it running again. They just needed a fancy sci-name for it.
      • by snarkth (1002832)
        Yeah, but imagine a laptop which is obsolete before it's power source fails.

          Now that'd be innovation...*g*

        snarkth
  • by zappepcs (820751) on Friday December 08, 2006 @12:40PM (#17163368) Journal
    Li-Poly batteries have been around awhile. Hobbyists were the first I know to use them. I don't know that they have improved in safety issues over the last few years, but perhaps you should see the following
    example of a li-poly flame out before buying li-poly batteries?

    http://www.rcgroups.com/forums/showthread.php?t=15 1687 [rcgroups.com]
    • So they don't explode, but they do catch on fire. I suppose you could put it out but that kind of choice is like the dentist asking you if you want a root cananl or a tooth extraction. Neither is very pleasant. Or so I'm told. :)
      • Re: (Score:1, Offtopic)

        by Control Group (105494) *
        An extraction isn't even in the same ballpark as a root canal in terms of discomfort at the time.

        Of course, there's a perceived benefit in keeping the tooth.
    • you do know that form does catch fire really easy right? The melted foam in the last pic is totally not a surprise. One can burn foam with a match. Maybe if the example used something that doesn't melt as fast, like an old laptop case? Don't movie people use burning foam cups in sound effects?

    • Deliberately overcharging a li-poly cell for almost an hour makes it BURST INTO FLAMES! OH NOES! And that is rated INSIGHTFUL? Jeez.

      Seriously. Charging batteries has *ALWAYS* been "dangerous". If anything, Li-Pol batteries are *safer* than other batteries, since they won't burst into fire from a short-circuit.
  • I thought lithium polymer was actually newer than lithium ion? Yeah, it's less energy dense, but it's a lot safer, as it is much less likely to burst into flames (though it can still happen from over charging or too-fast charging if I remember correctly).
    • I think the implication of the title is that they're turning to pre-existing technology, rather than starting from scratch (creating a new technology). I don't believe it's meant to imply that LiPoly is older than LiIon.
  • Kaboom? (Score:4, Funny)

    by sam_paris (919837) on Friday December 08, 2006 @12:41PM (#17163372)
    Is it just me or do others start to feel nervous when Sony start trying to push new battery technology..?
    • The article is slashdotted so don't bash me for NOT RTFA, please.

      That said, is it just me or does anyone else think the best way to push a new technology is to make an old tried and true one seem dangerous and unreliable.

      Kind of like making freon out to be the environmental bad guy just as the patent runs out and something new comes online to replace it.

      O.K. I'm paranoid but someone must have done this to make me this way.
  • by creimer (824291) on Friday December 08, 2006 @12:41PM (#17163386) Homepage
    Less power and less bang for the buck? Can't wait for the marketing people to spin that one.
  • Why? (Score:2, Interesting)

    by TheUnknownOne (810624)
    Why is less energy density a plus? I would like a laptop with a long battery life, and improvements in processor technology should be used to increase battery life, not reduce the capacity of batteries.
    • I'm guessing by lowering the density the chance of explosions (or general volatility) would decrease. But I don't know anything about it.
    • by SSCGWLB (956147)
      Could it be because they weigh significantly less per volume? So, if you need 20% more by volume but the battery weighs 50% less (I just made up these numbers), your battery might be bit larger but it weighs a LOT less. I could see how this might be a acceptable tradeoff for certain applications.

      Or, Sony is tired of replacing exploding batteries and is looking for a new type that fails in a less spectacular fashion :)
  • "These gel batteries can't provide the same sort of energy density as lithium ion batteries, but that's now a plus."
    Why is that a plus? Seems to me having more energy stored in my battery is a good thing. Shoddy manufacturing, exploding batteries and class action lawsuits notwithstanding.
    • by danpsmith (922127)
      Why is that a plus? Seems to me having more energy stored in my battery is a good thing. Shoddy manufacturing, exploding batteries and class action lawsuits notwithstanding.

      It's a plus because they hold less and they are more expensive, so Sony can sell you more expensive backup batteries which run out more frequently! Remember, someone has to pay for the price of exploding laptops...

  • These gel batteries can't provide the same sort of energy density as lithium ion batteries, but that's now a plus.

    Um, no it's not a plus. Well, maybe for Sony since they can't seem to manufacture LiIon batteries reliably. But for the rest of the industry, I'm pretty sure lower engergy density (and hence shorter runtimes and/or larger batteries) is a minus. Otherwise we would all be running our laptops on alkalines.
  • lifetime? (Score:4, Interesting)

    by compro01 (777531) on Friday December 08, 2006 @12:46PM (#17163470)
    unless things have changed, i remember that the original iPod used a Lithium-polymer battery and i've heard that the useful lifetime of the battery wasn't that great (less than 50% usable capasity after 1 year), which prompted Apple to switch to a regular lithium-ion for the 2nd and later generations.

    has anything changed with this or is what i've heard BS?
    • Re:lifetime? (Score:5, Informative)

      by Rob the Bold (788862) on Friday December 08, 2006 @01:17PM (#17163908)
      has anything changed with this or is what i've heard BS?

      You can design in a larger and more costly charger manager in a notebook battery than you can in a digital audio player. More sophisticated charge management ICs have dead battery precharging cycles, thermimstor inputs to watch cell temp, and smarter logic for charging battery depending on state of charge when you plug it in to the charger. The smaller, low cost chargers you use for small electronics aren't nearly so smart, most just stop charging at a given voltage (or at the end of the safety timeout).

      Anyway, you can get better battery lifetime if you can afford the cost and size of a fancier charger. Doesn't mean the guys designing small devices are doing a bad job, they just have a different tradeoff to make when doing the design.

      • I have an original 5GB iPod, and until early this year when I bought a new one, I still got over 11 hours of battery life.
    • I was in charge of fixing about a dozen compaq iPaq 3650's from quite a few years ago- and I'm fairly certain they had a lithium polymer battery (it was a little squishy, flexible pack (don't bend it intentionally though)- all 10 of these units wouldn't hold a charge and wouldn't charge up. They were used heavily, but recharged a little too often some of the time and not often enough the rest of the time. Some of them started to have the charge problems then, so they were taken out of service and after abou
    • i remember that the original iPod used a Lithium-polymer battery and i've heard that the useful lifetime of the battery wasn't that great (less than 50% usable capasity after 1 year),

      I don't know if I'm lucky or what, but my 1st gen iPod still holds a 9+ hour charge - I know because of the class action lawsuit that included a method for battery testing, and which did not include my iPod as a result of the test.
    • Apple recently filed a patent for a device that uses LiPo.

      If Apples using em, they'll be be trendy enough that everyone will want em ;o)
  • by syncrotic (828809) on Friday December 08, 2006 @12:46PM (#17163474)
    High end notebooks from Dell, IBM, and possibly others all use lithium polymer batteries for their drivebay batteries, where space is extremely tight and the geometry is suboptimal for cylindrical cells. Li-polymer batteries can be made into very thin shapes and don't need a metal case to contain individual cells. Because of this, the energy density is actually higher. I think the reason they're not in widespread use is simply that they cost more.
    • by edmudama (155475) on Friday December 08, 2006 @01:48PM (#17164310)
      exactly.

      Energy density of the raw charge storing material is lower with LiPo, but it doesn't require the same packaging/metal casing, so net energy density is higher.

      Something like 2.5 times as much power per weight as Li-Ion battery packs. It's revolutionized RC electrics.

      Models that were designed for NiMH cells and were getting 4-5 minutes of flight time, can now get 15 or more minutes of flight.
    • by volsung (378)
      Apple also uses lithium polymer batteries in the MacBook, MacBook Pro, and iPod Shuffle.
  • Bollocks. (Score:5, Insightful)

    by Control Group (105494) * on Friday December 08, 2006 @12:47PM (#17163494) Homepage
    No, that's not "a plus." That's a cost-benefit tradeoff on the manufacturing side, and a risk-reward proposal on the end-user side. Lower energy density means either shorter battery life or heavier laptops. I don't think anyone would call either of those results a "plus." They're tradeoffs.

    Moreover, there are plenty of Li-ion batteries out there that haven't overheated, burned, detonated, or imploded into naked singularities causing the annihilation of life as we know it. Which means, for those batteries, you get to have longer battery life or lighter laptops sans the death and destruction result, so the move from that state to the proposed solution isn't even a tradeoff, it's a pure loss.

    Covering for the inadequacy of your manufacturing/QC processes by making a worse product that's easier to make doesn't translate into a "plus." It sounds to me that the real plus would be if they moved to a power source they've obviously got in plenty - though I think the name "spintronics" has already been taken.
    • Lower energy density means either shorter battery life or heavier laptops.

      I wouldn't be too sure about that. The article doesn't really make it clear how well the density compares.

      Energy density isn't mass density. It might mean larger notebooks or lower battery life, but it doesn't inherently mean heavier batteries.

      The article says that Lithium polimer is more flexible in form factor allowing more choices at design time, so it's not a total negative trade-off
    • by Mr. Hankey (95668)
      I guess whether or not it's a plus depends on how much you value your life. I've used Li-Po batteries in other devices, and they're not that much worse than Li-Ion for most uses with reasonable draw. The lithium inside these batteries is dangerous, put in too much energy (typicaly more than 4.6v per cell for Li-Po) and it'll blow up regardless of whether it's a Li-Po, Li-Ion or Li-Mn. Have a look at this video clip, from a company that makes a Li-Po charging safety device, to see the effect:

      http://www.lipos [liposack.com]
      • So if you dead short a Li-po battery, you get some spectacular fireworks. If you dead short a Li-ion battery, you get somewhat more spectacular fireworks. By your rationale -

        Whether or not it happens to you is irrelevant. It only needs to happen once to do damage, and in the case of a plane it needn't be your laptop.

        - I fail to see how Li-po is better. For that matter, I don't know how you can justify using house current - if you dead short across your circuit breaker, you'll get some spectacular fireworks.
        • by Mr. Hankey (95668)
          In your rush to dish out your sarcasm, you appear to have missed the point. Li-Ion batteries have caused surprise fires and explosions in many devices by the customer - without being shorted or used outside of their specifications. We had a VAIO with a Li-Ion battery catch fire sitting on a table close to here a few years ago, never mind the Nokia phones exploding and the Dell/Apple laptops catching fire. Li-Po batteries are less likely to have these sort of problems since it's a more stable chemistry. Unle
      • Li-Poly batteries are extremely light. A big part of that is they don't need the "compressive" shell normal batteries have to hold everything together. So no metal casing in addition to the lighter material.

        You may think the lower eneregy density leads to more volume taken up by the laptop, but that doesn't turn out to be the case. The thing about Li-Ion (and most battery types), is that they need to be created in the form of cylinders, which do not pack very well. This menas when packing them into a rectan
    • by VWJedi (972839)
      Moreover, there are plenty of Li-ion batteries out there that haven't ... imploded into naked singularities causing the annihilation of life as we know it.

      So far, all of them fall into that category. And I, for one, really hope it stays that way!

    • Li-ion cells blow up if you short them, and aren't considered safe to distribute to consumers. What you get are Li-ion battery packs with bunch of protection circuitry and an armored case that keeps the protection circuitry from being bypassed if you drop your laptop. This armor takes up a non-trivial amount of the weight and volume of a battery pack.

      A Li-poly battery pack is going to be about the same in terms of weight and volume for a given capacity. It's be somewhat easier to break (no armor), but it wo
  • by bill_mcgonigle (4333) * on Friday December 08, 2006 @12:48PM (#17163500) Homepage Journal
    You mean "current notebook battery"?

    I'm typing this on a c2d MacBook Pro [apple.com] which lists a lithium polymer battery as its spec. Third bullet line down on that page. I also have a 5GB iPod that uses a lithium polymer battery [apple.com]. Apple went Li-Ion for later iPods, probably for higher capactiy, but I'm on my second battery in 5 years and it gives me more than 8 hours of playtime (haven't tested it beyond that).

    I guess that means Apple isn't using Sony for its current batteries?
    • by VEGETA_GT (255721)
      Actually Apple was using Sony for its batteries and they did a battery recall a day after Dell did. Was fun as I was working at apple at the time. In the end Lithium ion batteries are every ware, form AAA to the laptops, cell phones, ..... In the end if sony changed to a older tech, dose not mean they well force the rest to follow. I believe this well hurt sony more then anything as I am betting there are many other company's willing to make lithium ion. and the risk of one exploding is rather small really
      • I believe this well hurt sony more then anything as I am betting there are many other company's willing to make lithium ion. and the risk of one exploding is rather small really compared to how much they are used.

        Reading between the lines, I'm guessing Sony figures it cost most to handle the recalls, direct and indirect costs, than they were making as profit in the Li-Ion business. If Li-Polymer batteries are less likely to be recalled, they should profit more even if their volumes drop.
        • by VEGETA_GT (255721)
          you may be right, but again the size comes into play here. People have say 4 hr's battery life on a 6 lb laptop. they are not going to want to lose the battery life or have the laptop heaver. Remember people grow accustom to things, and if you can't provide they go else ware. Also note besides Sony, have you seen any other mass lithium ion battery recalls. also people besides Sony are still making Lithium Ion, meaning those companies well most likely see a increase in there profects with some competition go
    • From what I understand, LiPol batteries were designed specifically for a bunch of brief charge cycles, like you'd get in a portable electronic device. Since few of us let our laptops run down entirely, this mean that you won't have to recondition them.

      That said, their capacity does drop over time, and judging from the cell in my MP3 player, they last about 2 years before it becomes noticeable. It's just that you can't fix it yourself.
  • In the RC aircraft world, Lithium Polymer batteries are king, due to their fairly high capacity and incredibly high current draw (some packs up to 40 amps). Several folks have tried making packs out of laptop LiIon cells, but they just can't deliver the amps. Is this true that LiIon packs hold more energy but have a lower maximum amp draw? Most laptops draw about 1-3 amps I believe, so this isn't really an issue, but I am curious.
    • by Calinous (985536)
      Laptop batteries are at some 18 Volts (or so I've seen on one). If you take into account a laptop with P4 Mobile processor, it can't take (the processor itself) less than 50W. Add to this other electricity uses (hard drive, display), and you end up with a need for up to 10 amps at a time.
  • by Zondar (32904) on Friday December 08, 2006 @12:54PM (#17163598)
    I know the model RC community does. Higher end planes and helicopters, especially the all electric ones, tend to use LiPo batteries.

    What scares me though... many many reports of fires due to overcharging (shoddy chargers). It is suggested to always charge the LiPos in a 'battery bunker', a clay pot filled with sand, with a lid.

    Isn't that what they were trying to prevent with the new laptops?
    • What scares me though... many many reports of fires due to overcharging (shoddy chargers). It is suggested to always charge the LiPos in a 'battery bunker', a clay pot filled with sand, with a lid.

      If one is really concerned about explosion/fire, I'd leave the lid off -- at least don't fasten it down. Then the setup would resemble a munitions loading bunker.

      • by Zondar (32904)
        From one battery-bunker manufacturer's website:

        "The loose fitting lid locks on to contain the fire and allows the smoke and flame to vent around the lid and wire slot. The lid is designed to take the initial jolt that occurs."
  • Be VERY careful (Score:5, Informative)

    by IflyRC (956454) on Friday December 08, 2006 @12:59PM (#17163672)
    As my name implies I fly R/C aircraft as a hobby. Within the last few years electric powered models have really taken off. Most of this is due to the Li-Po battery. Lithium Polymer batteries are a subset of Lithium Ion batteries but the design of the cells are different.

    Li-Po batteries are small and light and can produce a higher continue current than lithium ion. They are very powerful batteries.

    One of the problems though...and why I generally stay away from them is that they explode. They can easily become unstable if dropped (or crashed). I don't claim to be an expert but the cells in a lithium ion battery are metal - they can sustain an impact and vibration where as the cells in a lithium polymer are mostly plastic which can cause a mix of the chemicals inside and cause the battery to heat up until it vents and then explodes.

    Fire caused by overcharging [rcgroups.com]

    Video of a lipo battery going bad. [helihobby.com]
    • by lp60068 (727840)
      Wow - that video of a battery blowing up is good.
      I don't see this as safer...
    • by NMerriam (15122)
      As my name implies I fly R/C aircraft as a hobby. Within the last few years electric powered models have really taken off.


      Thanks folks, I'll be here all week! Try the fish. :P
    • Re:Be VERY careful (Score:5, Informative)

      by bughunter (10093) <bughunter@noSPaM.earthlink.net> on Friday December 08, 2006 @07:29PM (#17168790) Journal
      My job is building hi-rel batteries for launch vehicles and spacecraft, so let me share some facts that seem to be in confusion in this forum.

      First, The distinction of Li-Poly from the general chemistry of Li-Ion is in the electrolyte. Instead of a liquid or gel electrolyte, the Li-Poly cell uses a thin sheet of conductive polymer doped with ionic compounds. Now while this polymer electrolyte has less mobility than a liquid, resulting in a lower energy density (J/cm^3) and power density (W/cm^3), in practice the manufactured shapes can be more complex than the coin or cylindrical shapes imposed by liquid electrolytes. Therefore more "battery cell" can be stuffed into otherwise unused volumes, and in many applications this maximizes the effective energy density beyond what can be achieved using cylindrical cells.

      Second, any Lithium chemistry cell using a Cobalt-alloy cathode (virtually all of them on the market today) is subject to a thermal runaway condition if the internal cell temperature exceeds 130C. This includes Li-Poly cells.

      Valence corp has patented a Lithium-Iron-Phosphate cathode chemistry that has less energy density, similar to NiCd, however the change to a Iron cathode eliminates the thermal runaway possiblity, making the cells much safer. These will soon be available commercially from DeWalt as battery packs for their cordless power tools. Here [dewalt.com] is a press release... note that Valence later bought the company referenced therein, A123 Systems. (I wonder if there's been a delay somewhere - DeWalt was marketing this much more heavily just a few months ago, now you have to do a search on their site to find any reference of it.)

      Another company, Altair Nanotechnologies, has patented a Litium Titanate Spinel anode technology that also claims to eliminate the risk of fire and improve on both the Energy Density and Power Density of vanilla Li-Ion. However they have yet to actually deliver cells (to me anyway, despite many requests). And this chemistry is not exclusive to the Iron Phosphate cathode, meaning someone with all of the proper patent licenses could combine the two and make a high energy-density, non-exploding laptop battery that does even better than the Li-Poly battery I'm using in my MacBook Pro right now.

      Finally, here's a link [batteryuniversity.com] to the "Safety Concerns" page of the "Battery University" site which is an excellent user's reference for Li-Ion secondary batteries, among others. And here is a link [valence.com] to a Valence Corp white paper that describes their LIP cells. Lastly, here is a PDF [altairnano.com] of Altair Nano's marketing material describing their claims of safety advantages their Titanium spinel material offers to commercial batteries.

  • The Lithium Polymer gets hoy only when it is charging, as oppose to the common Litium ion battery today gets hot when it is used.

    So, when it blows up, there is a smaller likelihood people will be around it!
  • by sith (15384)
    The 17" powerbook G4 and all the macbooks and macbook pros use LiPoly batteries. So does the iPod. (Notice that the Sony recall was only for 15" and 12" powerbook g4s)
  • Heavy, Man. (Score:2, Informative)

    by tryptych (1023927)
    I use Lithium Polymer batteries in my SLR camera. It's a whacking great lump that bolts on the bottom, and although it's way better than conventional AA's (even NiMH), they are hellishy expensive ($300-£400), and they are bloody heavy! One further factor is it's a typical Sony ploy. Invent a totally unique accessory that only Sony make, and charge three times the price for it. (ie, $10 power supplies with an oddball connector they sell for £150) That's why I wont buy anything from those people.
  • Do these new batteries come ready to explode like the lithium ion batteries or do we have to pay extra for that feature?
  • Lithium (Score:3, Funny)

    by mqduck (232646) <mqduckNO@SPAMmqduck.net> on Friday December 08, 2006 @01:55PM (#17164398)
    Never trust lithium. I took it for years and my brain NEVER worked. I wish I was joking.
    • by brain1 (699194)
      No you're not doing it right. UNWRAP the battery first - then chew on it. Sheesh.
  • > Instead, it is contained in a polymer gel. These gel batteries can't provide
    > the same sort of energy density as lithium ion batteries, but that's now a
    > plus."

    Better yet, go back to carbon-zinc dry cells.
  • by c0d3r (156687)
    Reminds me of that old Nirvana song: "I'm not gonna crack"..Wonder if Sony is going to make laptop batteries with a Lithium Polymer.
  • http://en.wikipedia.org/wiki/Lithium_ion [wikipedia.org] -- Appearing in 1991...

    http://en.wikipedia.org/wiki/Lithium_polymer [wikipedia.org] -- appearing in 1996...
  • by MoronBob (574671)
    Isn't that the same kind of battery that Uncle Rico is selling?
  • by jpetts (208163) on Friday December 08, 2006 @04:19PM (#17166308)
    Lithium is a metal with a melting point of 453.69 F and a boiling point of 1615F. It is a REACTIVE metal (being one of the alkali metals), but it is definitely not volatile.
  • Who cares...as long as it's WildCharger compatible!

    http://www.wildcharger.com/ [wildcharger.com]
  • There have been reports of lithium polymer batteries spontaneously igniting after being damaged, while being charged incorrectly, after being shorted, and for a variety of unexplained reasons.

    See this thread entitled "Data - Complete Guide to Lithium Polymer Batteries and LiPo Failure Reports": http://www.rcgroups.com/forums/showthread.php?t=20 9187 [rcgroups.com]

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