Picture of a disassembled Duracell 9v battery. Below the terminal assembly is a clear plastic case where you can see six sets of stacked rectangular terminals and fillings.

  • @radix@lemmy.world
    link
    fedilink
    English
    597 months ago

    I had an old 12v power tool battery die, so I took it apart to find 8 generic AA rechargeables wired together. I suspect lots of batteries are multiples of 1.5v (9/12/18) because they’re just stacked smaller cells that are already mass produced.

    • Dave.
      link
      fedilink
      747 months ago

      Battery chemistry produces fixed voltages depending on what you use. It depends on where the active components sit on the electronegativity table.

      The typical ones are:

      Zinc-carbon and alkaline - 1.5 volts per cell.

      Lead acid - 2 volts

      Nickel Cadmium - 1.2 volts

      Nickel Metal Hydride - 1.4 ish.

      All the Lithium ion combos - 3.4 to 3.7 volts.

        • Dave.
          link
          fedilink
          107 months ago

          The voltage range depends a lot on cell construction, temperature, load or charge rate, and chemical mix.

          For example “lead acid” batteries with lead and sulphuric acid have a cell chemistry voltage of 2.05 volts but their nominal range is 1.8 to 2.4 volts per cell. Translating that to a 6 cell “12 volt” car battery gives you a range of 10.8 to 14.8 volts.

    • Altima NEO
      link
      fedilink
      English
      137 months ago

      Yeah they had nicad or nimh batteries donated together to create the battery pack. I had an old shaver that was the same way. Laptops with replaceable batteries do the same things

      Current power tools still do this, but with 18650 lithium cells, or some larger variant. But now the trendy thing in power tool batteries are the pouch cells, like the kind found in cell phones and slim laptops. I gotta they’re more energy dense, since there’s less of an air gap between cells.

      • @Aceticon@lemmy.world
        link
        fedilink
        2
        edit-2
        7 months ago

        There didn’t used to be efficient ways to convert DC/DC voltages up in electronics (you could drop it, though also not very efficiently), but nowadays there are technologies to do that and hundreds of choices of integrated chips that do most of the work along with a inductor and a diode (these being the very minimal set of parts) with about 90% efficiency, so stuff that needed higher voltages and had to use multi-cell batteries for it in the past, now can be done with batteries that output much lower voltages along with one of these voltage converters (called “boost converters”).

        (For those in the know, yeah there was already something before for lower currents called voltage pumps, using only capacitors, but those thongs couldn’t handle higher currents).

        Anyways, all this to say that manufacturers can now choose to use smaller and simpler batteries for the equipment they make and convert voltage up in circuitr cheaply and with minimal losses, hence you’re much more likelly to see that when it makes economical sense for them (for example, by being able to use the more common battery types rather that having to have unique custom batteries, as the latter are more expensive since they do not get the same savings from the economies of scale of mass production).

      • @Aceticon@lemmy.world
        link
        fedilink
        57 months ago

        Different materials used as basis for different battery techs will produce different voltages when the ions go to the anode (something to do with the energy that can gained when the ions combine with the material of the anode being only one of a fixed set of possibilities due to the available free bands in the atomic structure - please check Wikipedia for a proper and correct explanation rather than my vaguelly remembered one) which is why Lithium batteries are always around 4V without extra electronics to drop the voltage (which make them less efficient) and voltages above that require putting multiple cells in series to add their voltages.

        As it so happens, the techs for the Carbon-based, Alkaline and Cadmium all have this voltage be around 1.5V (though you might have noticed that the Cadmium ones are a little lower than 1.5V and Alkaline a little higher) so you need 6x cells in series of batteries of that tech to get 9V.

        That I know of, there is no consumer battery tech which has a single cell voltage of 9V and I don’t even know if there is any substance or combinations of substances that makes that possible at all.

    • @HakFooOP
      link
      307 months ago

      I actually took it apart hoping to find the AAAAs.

      • @lemmefixdat4u@lemmy.world
        link
        fedilink
        57 months ago

        Cheap low-capacity 9V batteries are still 6 AAAA cells. The flat cells allow higher capacity in the same space, so you find them in the batteries that advertise themselves as long-lasting.

    • ares35
      link
      fedilink
      127 months ago

      the little round ones are what i remember when i took a 9v apart when i was a kid.

  • @HakFooOP
    link
    187 months ago

    Disapointingly, it came wrapped in a branded metal case that you have to pry apart to see the cool layers.

    • FQQD
      link
      fedilink
      English
      187 months ago

      They need to make transparent ones as a special edition xd

      • Flying Squid
        link
        fedilink
        497 months ago

        They used to think that sort of thing was cool in the 90s.

        They were right. I stand by this claim.

        • ares35
          link
          fedilink
          97 months ago

          we must be due for that to be ‘retro’ trendy again.

          • Flying Squid
            link
            fedilink
            117 months ago

            I hope so. I don’t know if it would work to make a smartphone in a clear plastic case like that phone, but if someone did it, people would probably just complain because it was plastic and not metal or something.

            • @ThatFembyWho@lemmy.blahaj.zone
              link
              fedilink
              English
              57 months ago

              IIRC there’s a transparent version of the Fairphone 5. Not that it’s as aesthetically interesting inside as older tech, more of a statement about the device’s modular design.

              • Flying Squid
                link
                fedilink
                17 months ago

                I just looked it up. It’s a little too opaque for my tastes based on what I’m talking about but you’re right, it’s not as interesting inside. Maybe that’s why other companies stopped doing it. It still makes sense if you want to show off the design of the device in a specific way like you said.

            • Dharma Curious
              link
              fedilink
              57 months ago

              I can’t remember who did it, but there’s a YouTuber who always clearifies his phones when he gets a new one by removing the back and putting a gorilla glass back on it. Haven’t seen his videos in a while, I don’t think, but he has several iirc.

              • FQQD
                link
                fedilink
                English
                37 months ago

                I think “Phone Repair Guru” (or something like that) does it similarly.

        • Thorned_Rose
          link
          fedilink
          87 months ago

          About a decade ago I told my spouse I wanted to customise my PC with a perspex case and some lighting inside. He was all bleurgh, why would you want to do that?! His current PC has a glass side and rainbow lights inside.

          I also stand by this claim and have since the 90s. Thank you and good day, sir.

        • Zerlyna
          link
          fedilink
          English
          57 months ago

          I had one of those in my bedroom growing up!

          • Flying Squid
            link
            fedilink
            37 months ago

            A friend of mine had one as a teenager and then brought it with him to his dorm room after high school. We called it Pavlov because it had to be answered when it rang.

        • Dion Starfire
          link
          fedilink
          47 months ago

          I saw one of these at Target the other day in the $5-and-below section. Except it wasn’t a full phone, it was a nostalgia grab designed to be a wired “headset” for a cell phone with a headphone jack.

        • BolexForSoup
          link
          fedilink
          17 months ago

          I would seriously consider paying for a landline just to have one of those

        • FQQD
          link
          fedilink
          English
          97 months ago

          Who needs protection when you have cool lookin batteries?

          Jokes aside, maybe a print of how the insides look would be cool, too. Like the phone cases from that recent JerryRigs drama.

  • @perviouslyiner@lemm.ee
    link
    fedilink
    English
    177 months ago

    Better use of space - they used to be just six coin cells with a load of empty space for a wire to connect the top connector to bottom of the stack

  • @Boozilla@lemmy.world
    link
    fedilink
    English
    16
    edit-2
    7 months ago

    Those super expensive rechargeable batteries they sell for cordless power tools have smaller cylindrical batteries inside, wired together.

    The Torque Test Channel on YouTube took some apart for their insane Dewalt backpack battery modification video. It’s a fun watch.

    • IWantToFuckSpez
      link
      fedilink
      17
      edit-2
      7 months ago

      Open any lithium battery pack and you’d find those cylindrical lithium cells. Even a Tesla battery has those. Only things that need to be flat like a laptop or a phone use a pouch battery.

      • FQQD
        link
        fedilink
        English
        77 months ago

        On older laptops they used cylindrical cells too. On mine, you can clearly nake out the shape of the housing on the removable battery.

  • @MonkderZweite@feddit.ch
    link
    fedilink
    4
    edit-2
    7 months ago

    Btw, why do the flat ones (4.5V i think?? use 3 round batteries instead of rectangulars? They could have more capacity due to less space wasted.