I hate this scale, it says low battery and shuts off after just 3 months of sitting in the drawer. It infuriates me that there’s still a lot of energy in the battery, I can use that in remote controls with no issues

If there’s enough battery to say “low battery”, then there’s enough battery to show the measurements!

  • Thorry84@feddit.nl
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    1 month ago

    That’s because of the way these scales work. They use a material that deforms under stress and when it deforms the resistance changes. By putting current through this material and measuring the voltage drop, it can be mapped to how much stress the material is under and thus how much weight is on the scale.

    This is a pretty roundabout way and has a lot of caveats, but it is very cheap. So cheap scales always work this way. That’s why they aren’t super accurate and have deviations depending on things like temperature. Another big downside is any permanent deformation ruins the calibration, giving incorrect results. That’s why you never put more weight on kitchen scales than it says, it will break them.

    The issue you are running into is the way it measures. It applies a very specific voltage and current in order to get the result. The lookup table it uses is only valid within a narrow range. When the battery voltage goes outside that range, it can no longer perform the measurement. Even though there’s plenty of juice for things like the little processing chip and the LCD display. They don’t need a lot of power and can do with low voltages. But it can no longer weigh anything so it just errors out with a low battery warning.

          • B0rax@feddit.org
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            1 month ago

            Doesn’t help when you need 3.3V and the batteries are now down to 2.5V they are not putting a boost converter in there.

            • chonglibloodsport@lemmy.world
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              1 month ago

              Right. If your design requires 3.3V minimum then putting in a 3.3V battery and no boost converter is just dumb (or extremely user-hostile).

          • itsmect@monero.town
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            1 month ago

            Batteries have one advantage over over supplies: extremely low noise. Even an good LDO will bump up the noise floor, and a cheap lcsc part will do so too. Plus you’s want a reasonably low dropout and quiescent current, which also increases price. Maybe 10ct in volume is reasonable for such a part - and yes, that will absolutely eat the margin

            • chonglibloodsport@lemmy.world
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              1 month ago

              That’s definitely true. But I would definitely pay more for a scale with ultra long battery life.

              I made the mistake of buying an off brand digital calliper and now like an idiot I find myself removing the battery when it’s not in use just to avoid damn thing running flat in one month thanks to its atrocious standby current which enables the display to turn on instantly when I move the slide (rendering the on/off entirely moot).

              Next time I’ll just bite the bullet and buy a Mitutoyo.

              • itsmect@monero.town
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                1 month ago

                I find spending a bit more on batteries goes along way. Although the nominal voltage and size may be the same, better batteries have lower internal resistance, ie provide the same current with less voltage sag. This prevent the low bat detection from tripping prematurely.

              • Juvyn00b@lemmy.world
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                1 month ago

                Lol I must have one similar. Burned through a battery in storage and when I replaced it, I noticed that the display is still active even when off - such a weird design. I pop the battery half out for storage every time now.

                • chonglibloodsport@lemmy.world
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                  1 month ago

                  It’s a terrible design. If they removed that dumb always on feature and used a proper physical power button the battery would last basically forever.

              • tibi@lemmy.world
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                1 month ago

                The problem would be solved if these scales would take a AAA battery which has a lot more capacity than a tiny cell.

      • XeroxCool@lemmy.world
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        1 month ago

        Eventually, the battery drops lower than the device needs. So no, none of which is fixed by a voltage regulator.

  • forrgott@lemm.ee
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    1 month ago

    This is probably not what you wanna hear, but when the battery gets low, the current gets weaker. If the current gets too weak, the scale becomes more and more inaccurate. Like, wildly so. In other words, the alternative is to lie to you. Badly.

    • jdnewmil@lemmy.ca
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      1 month ago

      Agree. For clarity, the circuits that show the low-voltage status are much less hungry for current than the circuits that measure weight. So no, having enough battery to report low voltage does not imply that there is enough to make an accurate weight measurement.

    • XeroxCool@lemmy.world
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      1 month ago

      I’m bummed that when I had a Thinner bathroom scale, I could weigh myself before and after using the bathroom to see how much I expelled. It was consistent and really useful knowing its precision during keto months (lost up to 3lbs a week). Now I have a Taylor scale that will report the same weight over and over if it’s relatively awake and you change less than 5lbs. So, no thanks to scales that lie.

  • irotsoma@lemmy.world
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    1 month ago

    That’s not really how it works. The components of the scale require a certain amount of current especially if it’s digital in nature. As a battery approaches being drained, it produces less current. Less current can often power an analog device to a lesser degree, like lighting up an indicator light or LCD or even the IR LED light on a remote, just very dimly. But the tolerance of the weighing components is probably much less than the tolerance of the LCD panel or LED bulb. So many devices use an LCD or indicator LED bulb to show that the device isn’t necessarily broken, it just needs new batteries.

    If it’s sitting in a drawer and getting drained, then it’s probably not turned off properly or it may be the type that turns on automatically when it gets pressed down and inside the drawer it’s getting activated. Instead try taking the batteries out of any device that sits around for a long time without use. It will prevent accidental draining and also reduction the likelihood that the batteries will leak after a time. I usually pop the batteries part way out or put them in a small bag that I attach to the device with tape or a twist tie. Just make sure they aren’t touching anything metal and that the poles aren’t touching each other. Batteries will lose charge over time, but with alkaline batteries, that’s usually years, not months. Rechargeables generally take much less time, though.

  • needanke@feddit.org
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    1 month ago

    I have the same scale and bought a few rechargable ithium-Ion AAAs and they work line a charm having a constant voltage until empty.

    Only downside is that you don’t get any warning when they are about to run.

    (Something like that: https://www.mediamarkt.de/de/product/_verico-verico-li-ion-akku-loop-energy-aaa-mit-usb-c-buchse-2er-pack-lithium-ionen-akku-109861637.html )

    Edit: nvm, just saw your comment about yours usung a coin cell it seems like there are some deviations between different models of the scale.

  • Treczoks@lemmy.world
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    1 month ago

    Normal AA or AAA battery, or a CR<something> button? If it is a button cell, try wiping it with alcohol before you insert it. Many modern button cells have a coating that tastes horrible to prevent people (children) from taking them into the mouth. I’ve noticed that on some brands, this coating measurably increases the resistance of the cell, not only reducing the the power it can deliver, but als making it appear “emptier” than they are ofor the measuring circuits. Wiping off the coating with alcohol (90% isopropanol) expanded the cells’ life (in a kitchen scale to boot!) significantly.

    • Moonrise2473OP
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      1 month ago

      It’s a cr2032 from Duracell with that coating, later I’m going to try that

    • azertyfun@sh.itjust.works
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      1 month ago

      My cheap scale will not work with my freshly recharged amazon basics AAAs. Apparently those do not hold up well enough under load. And of course any set of batteries that does work, discharges over a few months.

      So I just bought a cheap mechanical scale (not from Amazon) and I eyeball it for weights under 50g. Good enough and dead reliable.

      • TheOakTree@lemm.ee
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        1 month ago

        This may or may not help, but a nickel is very close to 5 grams. You may be able to slap something silly together with a bunch of nickels taped together :P

  • bstix@feddit.dk
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    1 month ago

    CR2032 batteries are hit and miss in my experience. Sometimes my car FOB burns through one a month2 and other times they’ll last years.

      • vxx@lemmy.world
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        1 month ago

        In my experience you can feel how good they are by how heavy they weight in your hand.

        • setVeryLoud(true);@lemmy.ca
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          1 month ago

          I actually just bought some Panasonic CR2032 and opened the packaging yesterday and I did notice they were heavier 😁

          • vxx@lemmy.world
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            1 month ago

            Funny that you mention Panasonic, because that’s the brand I noticed it first with.

            The Panasonic cells that come with a device are usually garbage, also the stuff you get on flee markets and cheap packages on the Internet.

            They apparently have cells that hold up and weight noticeably more.

            For the standard sizes like AAA, AA and D cells there’s only Duracell for me. They’re still miles ahead of their competitors imo.

            • setVeryLoud(true);@lemmy.ca
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              1 month ago

              It’s my first time getting name brand in a while, but it’s possible it’s like OEM tires, where the tires that come with your car don’t have as much tread as a new tire you bought yourself, even of the same model.

              • vxx@lemmy.world
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                1 month ago

                Exactly. They don’t want to provide them at all, but customers would get furious, so they cheap out as much as they can.

  • woelkchen@lemmy.world
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    1 month ago

    For decades scales worked just fine without any electricity. Maybe get one of those.

    • tiramichu@lemm.ee
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      1 month ago

      There’s also the option of electronic scales which are rechargeable via USB

  • Blackout@fedia.io
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    1 month ago

    My scale looks similar to this. If I leave it on it goes into sleep mode which still drains power slowly but turn on instantly as soon as there is weight on it. If I hold the power button when I’m done it turns off and makes a beep and then I have no issues turning it back on months later. Still on original batteries after 2 years.

    • dufkm@lemmy.world
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      1 month ago

      Nice, which brand/model? I have a scale for making pour-over coffee that has 0.1g precision, but I seriously doubt my scale is actually accurate to 0.1g.

      • crusty@lemmy.dbzer0.com
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        1 month ago

        Chef Matteo Preciso, though you can only get one if you live in Scandinavia or Finland as it’s a store brand.

    • Valmond@lemmy.world
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      1 month ago

      I have a 0.1 accuracy scale from aliexpress and it works everyday with its soon to be 10 year old coin battery.

      I’ll buy a rechargeable one if ever it goes to scale heaven.

  • IsThisAnAI@lemmy.world
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    1 month ago

    Didn’t think you were going to get a bunch of nerds telling you exactly why it works this way 🙄

    • Moonrise2473OP
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      1 month ago

      LOL genuinely thought it was a case of “engineer hates the user”, instead it was a case “management said we need to save 5 cents for the voltage regulator”

    • CmdrShepard42@lemm.ee
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      1 month ago

      “Bruh just use the finger scale to weigh out your weed. 1 finger = 1.7g and 2 fingers = 3.5g”

  • GreyJolly@lemmy.world
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    1 month ago

    I believe I have this exact same scale, and I also hate it. My main problem is that those capacitative buttons sometimes refuse to work, and it’s real nice when I’m trying to measure something in grams and it randomly gets stuck in pounds.