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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    2 months 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.

  • forrgott@lemm.ee
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    2 months 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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      2 months 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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      2 months 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.

  • Treczoks@lemmy.world
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    2 months 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.

    • azertyfun@sh.itjust.works
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      2 months 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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        2 months 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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    2 months 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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        2 months 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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          2 months 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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            2 months 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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              2 months 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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                2 months 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.

    • tiramichu@lemm.ee
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      2 months ago

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

  • needanke@feddit.org
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    2 months 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.

  • Blackout@fedia.io
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    2 months 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.

    • Valmond@lemmy.world
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      2 months 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.