Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
Compare cell phone plans using Wirefly's innovative plan comparison tool ×
Power Build

At Oxford, a Battery That's Lasted 175 Years -- So Far 211

sarahnaomi writes There sits, in the Clarendon Laboratory at Oxford University, a bell that has been ringing, nonstop, for at least 175 years. It's powered by a single battery that was installed in 1840. Researchers would love to know what the battery is made of, but they are afraid that opening the bell would ruin an experiment to see how long it will last. The bell's clapper oscillates back and forth constantly and quickly, meaning the Oxford Electric Bell, as it's called, has rung roughly 10 billion times, according to the university. It's made of what's called a "dry pile," which is one of the first electric batteries. Dry piles were invented by a guy named Giuseppe Zamboni (no relation to the ice resurfacing company) in the early 1800s. They use alternating discs of silver, zinc, sulfur, and other materials to generate low currents of electricity.
This discussion has been archived. No new comments can be posted.

At Oxford, a Battery That's Lasted 175 Years -- So Far

Comments Filter:
  • Bullshit (Score:5, Informative)

    by Anonymous Coward on Friday January 23, 2015 @10:59PM (#48890613)

    From The Fucking Article

    "You'd think it'd be annoying as hell for a bell to be going off, constantly, for 175 years—but the voltage left in the battery is so low that the human ear can't actually hear the ringing. Instead, the clapper oscillates back and forth between the bell constantly, which you can see happening in this video. At this point, the experiment is more of a curiosity than anything—Croft says that the battery pulls 1 nanoAmp each time it oscillates between the bell’s sides, which is an exceedingly low amount of energy."

    • Re: (Score:3, Funny)

      by Anonymous Coward

      I wonder how long it hasn't been ringing for.

    • Re:Bullshit (Score:5, Interesting)

      by dj245 ( 732906 ) on Saturday January 24, 2015 @12:17AM (#48890897) Homepage

      From The Fucking Article

      "You'd think it'd be annoying as hell for a bell to be going off, constantly, for 175 years—but the voltage left in the battery is so low that the human ear can't actually hear the ringing. Instead, the clapper oscillates back and forth between the bell constantly, which you can see happening in this video. At this point, the experiment is more of a curiosity than anything—Croft says that the battery pulls 1 nanoAmp each time it oscillates between the bell’s sides, which is an exceedingly low amount of energy."

      1 nanoamp is so tiny that it may be being recharged from the environment somehow.

      • Re:Bullshit (Score:4, Interesting)

        by jimmydevice ( 699057 ) on Saturday January 24, 2015 @01:16AM (#48891067)

        I expect you are correct. Put the bell in a Faraday cage and see if it stops twitching. The question is, is the signal being switched, electrostatic, magnetic?

        • How the hell do you generate 2KV?

          • It's an electrostatic bell, so around 1KV should be enough to run such a small one. I imagine the battery has, say, 500 discs at 2V each, all in series.

        • Yes, it's being switched. The clapper itself is the switch. Find a picture on the Internet of the whole device, and you'll see that the clapper switches the current between the two batteries. TFA only shows the lower portion. You can't even see the "piles".
      • Re:Bullshit (Score:5, Insightful)

        by Anonymous Coward on Saturday January 24, 2015 @01:20AM (#48891077)

        > 1 nanoamp is so tiny that it may be being recharged from the environment somehow.

        At that rate it doesn't need any recharging. A continuous 1 nanoamp draw (it doesn't make sense to say it draws 1 nanoamp per oscillation because amperage is a rate not a quantity) would discharge a small 1 Amp-Hour battery over one billon hours, or 114,000 years. The fact that it hasn't discharged through interal leakage is pretty impressive though.

    • Re:Bullshit (Score:5, Informative)

      by Solandri ( 704621 ) on Saturday January 24, 2015 @12:22AM (#48890917)
      From a little googling, the voltage between the terminals is 2 kV. The clapper draws about 1 nA.

      (175 years) * (2 kV) * (1 nA) = 11045 Joules ]

      Which in terms most people can relate to is about 3 Watt-hours, or about the same as a singe AA battery. Not very impressive.
      • Re:Bullshit (Score:5, Insightful)

        by Anonymous Coward on Saturday January 24, 2015 @12:44AM (#48890993)

        Well, put a AA in a box and come back in 175 years, and try it out. Then we'll see how impressive that is.

        • Re:Bullshit (Score:5, Funny)

          by fustakrakich ( 1673220 ) on Saturday January 24, 2015 @03:14AM (#48891423) Journal

          Then we'll see how impressive that is.

          Not nearly as much as his coming back...

        • by itzly ( 3699663 )

          A regular AA can't do this. But it wouldn't be particularly hard to design a battery that could provide such a tiny current for a long time. It's just that there's very little practical applications for such very low currents.

        • by lgw ( 121541 )

          Well, put a AA in a box and come back in 175 years, and try it out. Then we'll see how impressive that is.

          Oh-ho, smart guy, see how may of those you'd sell!

          It is impressive though. Torpedoes need a high-power battery that can be stored for many years and still be at 100% when needed. They used to cheat, though, and use a wet cell with the chemicals stored separately - mix everything together when it's time to load, and you're ready to go. No leakage unless there's actual leakage. I wonder what they do today - a dry cell with no leakage would be safer and easier.

          • by itzly ( 3699663 )

            Dry cells wouldn't be able to provide much instantaneous current.

            • Why would they need that much instant current? The battery doesn't power the torpedo through the water, it just runs the guidance system.

              Population is provided by "Otto fuel II" which is a hot expanding gas that provides an average of 7 minutes of run time, but at 55+ kts it is enough.

              • Population is provided by "Otto fuel II" which is a hot expanding gas

                It's caused by something expanding, but it's not a gas. At least mine isn't.

              • by itzly ( 3699663 )

                I'm not an expert on torpedoes, but parent claimed that Torpedoes need a high-power battery. Given that torpedoes only operate for a short time, I drew the conclusion that they must provide a high current.

                • The Mk-48 ADCAP torpedo does require prep time, they aren't generally kept in a "ready to fire" situation all the time.

                  I would imagine one simple solution would be a capacitor, since the battery has to be good in storage for long periods of time, but when actually needed, only has to work for between 10 minutes an hour. So the torpedo has some spin up time while the battery charges the capacitor, however it is also possible to get its initial charge from the launching vessel (while in the tube), they are w

                  • by itzly ( 3699663 )

                    It is possible that if they drain the tubes and pull them out, the batteries have to be replaced.

                    If that's true, then we are talking about big currents (multiple Amps). A capacitor would not have enough capacity for a reasonable size. Batteries are much better.

      • Re:Bullshit (Score:5, Insightful)

        by bondsbw ( 888959 ) on Saturday January 24, 2015 @01:10AM (#48891049)

        That assumes the bell had been drawing the same current that entire time. The bell used to ring, meaning it was drawing much more current then.

        • Re: (Score:3, Insightful)

          by itzly ( 3699663 )

          Probably not a whole lot more. Batteries have a reasonably constant voltage during most of their discharge cycle.

          • Batteries have a reasonably constant voltage during most of their discharge cycle.

            Different types differ, and you don't know what type of battery this one is.

    • From the other FA - they've muffled the sound: "It is seen but not heard as the ringing is muffled, in the ground floor display cabinet near the main entrance of the Clarendon Laboratory." So, not BS.
    • It's part of a bunch of long-running experiments like the Queensland pitch drop experiment (running since 1930) and the Beverley Clock (running since 1864, although it was stopped briefly to move it and for cleaning). I particularly like the Beverley Clock (the Pitch Drop is pretty boring), a clock that's been running for over 150 years without being wound. You can buy your own (modern) equivalents of this clock [jaeger-lecoultre.com] if you have plenty of money (note that they don't list a price, you're requested to contact th
    • >Croft says that the battery pulls 1 nanoAmp each time it oscillates between the bell’s sides, which is an exceedingly low amount of energy

      That isn't a unit of energy. It tells you nothing about the energy consumed.

  • Oops (Score:5, Funny)

    by Anonymous Coward on Friday January 23, 2015 @11:03PM (#48890637)

    Actually the janitor changes it once a week when he cleans the room.

    • Re:Oops (Score:5, Interesting)

      by theVarangian ( 1948970 ) on Saturday January 24, 2015 @12:01AM (#48890847)

      Actually the janitor changes it once a week when he cleans the room.

      Hehe.. maybe he is. The municipal power company in Reykjavik, Iceland built a Focault pendulum [raunvis.hi.is] in their HQ as a showpiece. Local urban legend has it that after it was first installed the thing would stop swinging at seemingly random intervals which caused the artist and the physicist who designed it a lot of head scratching. No amount of calculations, physics theory and modelling could explain these mysterious disruptions in the predicted workings of the pendulum so finally they set up a camera to observe the thing. The footage showed the pendulum swinging away for hours and hours until suddenly a member of the cleaning staff walked into the frame, stopped, looked at the pendulum, reached out, stopped it with his hand and then walked out of the frame. Mystery solved... dunno if the story is true but it made me laugh.

      • There are similar stories in IT about a mysterious inexplicable server outage occuring at the same time each day, after office hours, that continued even after reformatting it to eliminate any software issue. When an administrator tried staying after closing time to watch it, he found a cleaner unplugging the mysterious humming box to plug the floor buffer in.

        • by Xolotl ( 675282 )
          I suppose you've only got the word of a Slashdot contributor, but I personally experienced one like this twice (at two locations), the only difference being the server wasn't being unplugged, but a high-current device was being mistakenly plugged into the same circuit and tripping a surge protector. In was case it was indeed after hours and it was indeed a floor buffer (the server was SUN Sparc). (The other case was much earlier and involved a kettle in the room next door and incorrect wiring.)
          • And _this_ is why I use things like these, wehre possible, in machine rooms and office spaces.

            http://www.homedepot.com/b/Ele... [homedepot.com]

            It protects the power plugs from being jarred and dislodged by someone poking around the back of an ill-managed server cabinet, and it can be labeled to indicate which machines or rack it currently powers. It can even be marked with the relevant fuse from the wiring closet.

        • Re:Oops (Score:5, Interesting)

          by msobkow ( 48369 ) on Saturday January 24, 2015 @08:14AM (#48892069) Homepage Journal

          I hate to tell you this, but most people who've worked support in manufacturing and office environments have similar stories. I spent close to two months getting paged by Northern Telecom in Bramalea, ON for a manufacturing system failure on the shop floor at 2-3 AM most days per week. It was only by deciding to hang out for an entire night watching the area that I found out it was being caused by a cleaning lady unplugging the network bridge to plug in her radio while cleaning the area.

          So seeing as I have one of those stories myself, I find them a lot easier to believe than most of you kids do.

  • Not a lot of power. (Score:3, Interesting)

    by Anonymous Coward on Friday January 23, 2015 @11:03PM (#48890639)

    At the current estimated power draw, thats only (1 nanoampere) * 175 years = 0.00153401723 ampere hours. It's a long time: impressive durability, but not really amazing capacity. Laptop batteries are often ~1000 times that. I don't know the voltage here, so I can't do energy comparisons, just total amp hours.

    • At the current estimated power draw, thats only (1 nanoampere) * 175 years = 0.00153401723 ampere hours. It's a long time: impressive durability, but not really amazing capacity. Laptop batteries are often ~1000 times that. I don't know the voltage here, so I can't do energy comparisons, just total amp hours.

      Deep space exploration could benefit from that kind of durability. It's lasted longer than most governments...

    • The durability is impressive. It's not like cleanroom fabrication and high-purity metallurgy were exactly top of the line in 1840, so I would have naively guessed that some mixture of corrosion and non-current-generating side reactions among impurities or airborne contaminants would have trashed it in less than a century, possibly a lot less, depending on the exact arrangement of the battery, even if the energy density is totally plausible in physics-experiment-land.
      • Maybe the summary should have mentioned the electrochemical series or something.
        • >Researchers would love to know what the battery is made of, but they are afraid that opening the bell would ruin an experiment to see how long it will last.

          Sort of suggests that nobody knows the chemistry involved, does it not?

          • by itzly ( 3699663 )

            Nobody knows the details for sure, but similar dry piles have been examined, so we have a good idea of the sort of stuff to expect.

    • by sjames ( 1099 )

      I don't know the actual voltage but dry piles of that type generally generate thousands of volts. It's probably a good thing the current is so weak! Effectively, it's a source of static electricity.

    • by AmiMoJo ( 196126 ) *

      0.0015 ampere hours = 1.5mAh. A smallish phone battery such as the one found in an iPhone 6 is 1800mAh, with previous generations being about 1500mAh, so it's about 1000x less than that. A high end phone is typically around 3000mAh.

      Laptops tend to be in the 5,000mAh range and upwards.

  • The Karpen Pile (Score:5, Informative)

    by psergiu ( 67614 ) on Friday January 23, 2015 @11:10PM (#48890673)

    http://en.wikipedia.org/wiki/N... [wikipedia.org]

    The Karpen Pile, currently on display at the Dimitrie Leonida National Technical Museum in Bucharest, Romania, still gives out 1V after 60 years.

    This one has a glass enclosure so it can be studied.

  • Hold your horses (Score:2, Informative)

    by Dan East ( 318230 )

    Let's put this in perspective. The only "amazing" thing here is simply that the chemicals used in the battery are very stable. The amount of energy we're talking about is very, very low.

    FTA, it takes around 1 nanoampere to ring the bell once. It rings around around 2 Hz. Thus it takes 2 nanoampere a second, which works out to 7200 nanoampere-hours.

    So let's see how long a AA battery could run that bell. The better AAs produce 3 amp-hour of power. That is 3000000000 nanoamperes. 3000000000 / 7200 gives

    • by lannocc ( 568669 ) <shawn@lannocc.com> on Friday January 23, 2015 @11:36PM (#48890759) Homepage
      I assume the bell used to actually ring, and therefore pulled more than 2 nanoampere for a good while.
    • Re:Hold your horses (Score:5, Interesting)

      by Dan East ( 318230 ) on Friday January 23, 2015 @11:48PM (#48890799) Homepage Journal

      Actually I have to correct myself. I assumed it was low voltage, like a single cell battery, and thus around 1-2 volts. That's not the case - the voltage is around 2,000 volts:
      http://www.sharingtechnology.n... [sharingtechnology.net]

      That means my calculations were off by a factor of 1333. So if you divide the times I stated for AA and D batteries by 1,333 and you'll get a more accurate figure. So even a deep cell 12 V battery, which is around 120 watt-hours, could only run the bell for 9.5 years. Guess that makes it more impressive than I thought.

      Or my calculations are still way off.

      • by sjames ( 1099 )

        Your figures look about right. It is a good bit of capacity but with really poor discharge characteristics. But it's no mystery. Being a dry pile, practically the whole thing is reactants.

      • by itzly ( 3699663 )

        You can't have "nanoamperes per second". Every time the bell swings back and forth you have a small charge that's transferred. Together, the small charges add up to a current, which is estimated at about 1 nA. Using the 2000 Volt estimate, the total energy after 175 years (1534017 hours) is 1534017 hr * 2000 V * 1 nA = 3 Watt hour, which is about equal to a single AA battery.

        • That's still not correct. It consumes 1 nA per ring, and it rings at 2 Hz. Thus it comes 2 nA per second, or 7200 nA per hour. According to your math you're assuming it only consumes 1 nA per hour, so that's off by a factor of 7,200.

      • by Rashdot ( 845549 )

        Or my calculations are still way off.

        Or the battery in your calculator is failing.

    • Correct me if I'm wrong but without knowing the voltage isn't comparing amperage hours to one another useless?

      5v * 1Ah = 5watt hours
      12v * 1Ah = 12watt hours

      Amp-hour isn't actually a unit of energy potential.

      One AA battery has about 2.6ah * 1.5v = 3.9 watt/hr
      One D Battery has about 18ah * 1.5v = 27 watt/hr

      175 years = 1533000 hours * 7200 nanoampere seconds per hour = 11.06 ah. Which if it's .1 volt would be 1 watt/hr of capacity. Or if it was 10v it would be 100 watt hour. Makes a pretty big difference.

    • by fnj ( 64210 )

      Thus it takes 2 nanoampere a second...

      "nanoamperes a second" is a completely nonsense measure. An ampere is already a time rate of transfer of charge. One ampere equals one coulomb per second.

    • Re:Hold your horses (Score:5, Informative)

      by quenda ( 644621 ) on Saturday January 24, 2015 @02:26AM (#48891283)

      FTA, it takes around 1 nanoampere to ring the bell once. It rings around around 2 Hz. Thus it takes 2 nanoampere a second, which works out to 7200 nanoampere-hours.

      Ouch! Your bad maths is making my head hurt. Amp is a measure of current, not energy or charge.
        A nA is one nano-couloumb per second. WTF does "nanoampere a second" even mean? Current acceleration?
        One nano-Amp for an hour is precisely one nano-Amp hour, duh!
      Better known as 3.6 microcoulombs. At 2kV, it is 7.2 milli-joules of energy.
      For that idiocy you get a +5? Mods need to stay in school.

      The better AAs produce 3 amp-hour of power. That is 3000000000 nanoamperes.

      FFS! First you equate amp-hours with power, and then you equate it with amps. Where did the time unit go?
      Your 3AHr battery at one nano-Amp will last 3 x 10 to the 9 hours, or 342,000 years. (neglecting internal leakage :-)
      Of course you will need a few of them in series to equal the 2kV of the Oxford Bell.
      What has happened to /.?

      (disclaimer: After that rant, I'm almost certain to have made an error myself.)

    • Dan East wrote :-

      FTA, it takes around 1 nanoampere to ring the bell once. It rings around around 2 Hz. Thus it takes 2 nanoampere a second, which works out to 7200 nanoampere-hours.

      What idiots modded this as "Informative"?

      He seems to think that a nanoampere is a unit of energy. Then suddenly he converts " 2 nanoampere a second" to "nanoampere-hours" which in terms of dimensional analysis [wikipedia.org] means he has somehow acquired a T (ie time) squared component from somewhere !

Success is something I will dress for when I get there, and not until.

Working...