cross-posted from: https://slrpnk.net/post/21299422
My kitchen scale is powered by a cr2032 lithium button battery. Yes, it was sloppy of me to buy the scale without seeing how it was powered. I only use the scale once or twice per month, yet these shitty button batteries only last a few months. It seems like I only get about ~6—12 measurements before the battery is dead.
WTF? This seems to defy physics. The scale automatically powers off. Of course it must always have some power because there is no ON switch. The scale detects capacitive touch taps or weight before turning on the display.
Digital calipers use a button battery which also only gives a dozen or so measurements before the battery is dead. It seems the calipers power on when the case is snapped shut. Maybe the rattling causes it to power on since it’s very touchy. Turns on with the slightest movement.
My bicycle helmet takes a cr2032, which only lasts a few months. Perhaps because it’s hard to remember to turn off the light. But still, it’s a shitty design because it has no timer or motion sensor. Or would a motion sensor itself use more power than the LEDs?
Questions:
- are button batteries a significant e-waste burden?
- are the batteries themselves really short lived, or are the appliances that use them all just poorly designed?
If there’s no on/off switch, it means it just goes to sleep and never truly turns off. Low power mode is nice for people who forget to turn things off, but it’s still draining the battery to monitor the sensors, so it doesn’t make a lot of sense for something that’s not used frequently.
The calipers remind me of my earbuds, which are always jostling in the case and disconnecting from the charging pins. I can be in the car and my music will suddenly stop playing on the radio because my earbuds came loose, connected, and took bluetooth priority. It’s irritating, and if anybody has a fix, let me know.
You could possibly mitigate the problem by keeping the battery out of the scale except for the few times you use it. Or add a snippet of tape you peel off and replace. Will the battery for the calipers fit in the case separately? It would be a PITA but so is constantly replacing them.
i might try this for the calipers. But the battery cover for the scale uses a screw… so i might opt to hack that to use external power of some kind.
We had a kitchen scale with a damaged control panel - the on/off button stopped working. I opened it up, cut one of the battery wires, and soldered in a switch. Cut a hole in the case with an xacto knife, glued the switch through it and put it all back together. Now it has a hardware power switch. If you’re comfortable with basic soldering, maybe that would work for you?
Button batteries suck and are absolutely e-waste, I have a small recycled sealable container just to collect dead CR2032’s. Every time I go through another one, I add another mental tally to eventually just mod any device I have that takes CR2032’s to instead take rechargeable AA’s. I’ve always suspected that the batteries are just too small to store enough energy to make the size worth it, and that devices that take them drain them on idle when the batteries are left in. I’ve had many CR2032 powered devices where they worked fine, I put them in a drawer, pull them out some weeks or months later, and it’s already dead. Battery drains without using whatever it’s in. Bad design from all directions
If you’re not worried about size or aesthetics, you should be able to wire up a replacement with a couple of rechargeable AA batteries or an external power supply.
Edit: there are “CR2032 batter eliminators” on the market, and here’s a diy version: https://hackaday.com/2020/04/24/a-cr2032-battery-eliminator/
i had the same issue with a cr2032 powered kitchen scale. my take is that the scale draws way too much power for the battery, and i guess its the display who draws most. (had the same issue with a kitchen thermometer). so it’s bad design i guess
Yes, they need to be recycled in a special way. And yes, most shitty “appliances” are shitty.
Use devices that work from the power net or at least those that can use standard and widespread accumulator batteries.
My kitchen scale that runs off of one of those batteries lasts for years, and I use it every day (coffee). Yours must have some kind of parasitic draw.
