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Examples lying around in my house: Bathroom scale: lovely it powers up when you tap it, but eats up 2 button cells a year for a few dozen uses a year Kitchen
by Nanite 4y ago
Examples lying around in my house:
Bathroom scale: lovely it powers up when you tap it, but eats up 2 button cells a year for a few dozen uses a year
Kitchen scales, bit more use, at least once a day but again 2 button cells a year
electronic caliper: Same, eats up 1 button cell a year, just sitting in my toolbox
Strangely enough none of our kids toys with batteries seem to suffer from this problem
How much extra cost does a hard on/off switch add to the bill of materials?
- Accacin 4y agoI had some digital bathroom scales, and I weigh myself pretty much every morning. The battery lasted a month, and those button cells are pretty expensive. I decided to take it to be recycled and just bought a mechanical one. It was a little annoying at first as it's not as precise, but for my purposes that works fine.
- criddell 4y agoThings that sit for much of the year I tend to remove the batteries when possible because I assume the batteries will leak. It might not be true, but it feels like battery quality has gone downhill recently (especially AA and AAA). I had very few leaks from the late 90's to about 2015. Since then, a lot more.
- spoonjim 4y agoThe kids toys are probably all manufactured by VTech which has solved this problem once across all of their products
- citizenpaul 4y agoYou are thinking too big. The "power supply" is probably produced by some china factory they order it from Factory A: Charges 7c per unit with a power switch. Factory B: Charges 3c per unit with no power switch. Wanna play the which choice did the C-Suite make game?
- theshrike79 4y agoButton cells are annoying, as you can't get those as rechargeable. I highly prefer AAA cells for those cases, you can get high-quality rechargeable cells from Ikea for a few coins.
- deleted 4y ago[deleted]
- nickff 4y ago>” How much extra cost does a hard on/off switch add to the bill of materials?” BoM cost is not the whole story; a physical switch can greatly complicate an assembly, and may require hand-soldered wires. In addition to those cost-related factors, external switches are usually quite ugly, and getting them right can be very challenging, so it’s much easier to just omit them.
- maxerickson 4y agoThe caliper and kitchen scale already have buttons. (they would both be shitty without a zero/tare button)
- bombcar 4y agoMany of these “auto zero” which is why you have to do the scale dance - tap it with your foot to turn it on, wait for it to say zero, then step on.
- maxerickson 4y agoYeah, my explicit mention of kitchen scales and calipers was intentional, they both become much more useful if the user can choose to zero the readout at any time. This is less true for a bathroom scale.
- thfuran 4y agoWent not just stand on it while it tares and ignore the negative when you step off?
- Tade0 4y agoCould you check the voltage on those cells next time you swap? I've found that seemingly similar devices have very different notions of what constitutes a discharged battery. I have a remote controlled humidifier and RGB LED - controllers for which use one and two infrared LEDs respectively. Both are powered by CR2025 button cells, which when new have an open circuit voltage of 3.3V and 2.7V once depleted. The two-LED device considers a 3V cell "dead", while the one-LED will happily work at this voltage.
- LorenPechtel 4y agoNo-load voltage is not the same as the voltage under load. The two-LED device drew more current and thus the voltage dropped more.
- nickff 4y agoVoltage doesn’t tell you much about the state of charge of a battery (especially with no load being applied), and there may not be much energy left at a battery ‘floating’ at 3V. The cutoff may have more to do with saving money on the power circuitry than what the designer thought was a ‘dead battery’.
- Aardwolf 4y agoBathroom scales, kitchen scales and calipers all have versions that work without electricity and aren't much less convenient (if not more convenient since no waiting for electronics to boot up slower than they should or clunky menus)
- galangalalgol 4y agoI try to never buy something that uses batteries and has a version that doesn't. My bathroom scale is a spring one. I do notice it isn't as accurate. The ones with weights are best, but those are quite expensive and take up a lot of room. For the kitchen I use electric for the extra precision while saving space.
- Loughla 4y agoI disagree. Measurements are funny things depending on the level of detail you need; analog versions of measurements are very clunky when you need precision. (now this is a bit much for bathroom scales and kitchen scales, but it was the calipers that interested me). When I need under .01 precision, my analog calipers just do not do the job as well as my electronic calipers. I can read them, but the last couple of thousandths are always sort of a guess. If I'm working on a project with tolerances of .01 or less, that's just not an option. I guess a fun middle ground - I have a set of mechanical calipers with a readout in actual numbers on the side like electronics would, but all mechanical, like clockwork or whatever it is in there, going to .001. They're infuriating to use, because the numbers are so small on the side, and at that level of detail, stupidly sensitive. edited the decimals because it's early and my brain shut off.
- bombcar 4y agoThe nice thing about analog is they don’t confuse you about precision - a digital caliper could be only precise down to .01 and yet show .0001 increments. For many things like a bathroom scale precision isn’t really needed anyway.
- rypskar 4y agoIs your caliper really that accurate and calibrated? In my experience you need a calibrated micrometer for that level of accuracy, especially to get a consistent measurements between several persons
- radu_floricica 4y agoBetween clicking on/off at least once a day, and changing batteries once a year, I'm picking changing the batteries. I'd also guess most people would just leave it on. They may have already tried that.
- Symbiote 4y agoI wish the Dymo label printer (for those labels printed on tape) had an off switch. Every time I want to use it, the 6 batteries are flat.
- AshamedCaptain 4y agoJust remove one battery and it's off? To be honest, I also have a Dymo label printer (very old model), and it does have a physical on/off switch, but even with the switch off it still consumes batteries like in 6 months.
- tristor 4y agoI gave up, bought the optional power adapter and just plug it in when I need to use it.
- mod 4y agoI have one and didn't even know it could run on batteries. I've always used a power cord.
- Buttons840 4y agoBoth bathroom and kitchens scales are large enough they can run on AA / AAA batteries and casually go a decade (or more) without replacement. Tangentially: I used to have a 3 button timer, it was a little LCD countdown display and 3 buttons. One button set hours, one minutes, and one starts / stops the countdown timer. I found this timer when I was a kid, used, and the 1 AAA battery it had lasted into adulthood, literally decades. I have since bought almost the exact same device - 3 buttons, one display - a few different times and the newer ones only last a year on the same battery. What's going on here? Presumably someone designed a new 3 button timer, since they can't just steal an existing schematic, and I guess just nobody cares to make it good? Why don't all 3 button timers last multiple decades on a AAA battery? I've seen the same thing with other small electronics, like the dozen or so stopwatches I've owned in my life. A few of them go strong for decades, others have their LCD display start fading in a year.
- LorenPechtel 4y agoThat's asking for corrosion damage from the battery. I've got a bathroom scale that goes several years on it's pair of coins even though it turns on only when stepped on. I suspect there's a physical switch involved, though.
- d0mine 4y agowhy don't they use gravity as the power source? I've seen scales that require pushing a button several times to power it. Getting rid of the button and using the full scales' surface seems like the next step.
- forgotmypw17 4y agoi have read that the build quality of batteries has dropped.
- narag 4y agoI have this ultracheap made-in-China big kitchen clock, with a single AA that I've replaced twice in eight years. I don't buy expensive batteries, more like in line with the clock. It has second hand (the kind that doesn't tick but appears to move uniformly) so there is some extra mechanical work.
- SiempreViernes 4y agoI have a oven thermometer that has two active parts which are linked via some sort of wireless system. One part is the one you plug the actual thermal probes into, and that then transmits data to a separate display. You can turn that one off. Then there is the separate display that lights up and beeps and what have you: this one doesn't turn off, presumably so you can admire it say "--" whenever you're not actively measuring the temperature of something...
- CogitoCogito 4y ago> Kitchen scales, bit more use, at least once a day but again 2 button cells a year I had a kitchen scale that would eat through its battery pretty quickly (within a month) even when not being used. I figured it could be an interesting project to open it up and try to figure out where the stray power draw was happening, but the obviously correct solution was just to leave the battery cover off and pop it in and out for regular use. Anyway my current kitchen scale was given to me as a present and has a mini-usb input to charge an internal battery. I personally found it to be a bit overkill, but at least I wouldn't need to get a new battery all the time. Then I realized that it can't be used when plugged in and charging. As in even if it is fully charged, it will not work when plugged in a charging. I can't believe that design idiocy. The engineers/managers/everyone involved in the production of this product should be ashamed.
- chippiewill 4y agoThey should have taken the apple approach and put the charging port on the bottom so you couldn't even lay it flat on its bottom with the charger plugged in.
- rebuilder 4y agoI dropped my kitchen scale and it broke, so I had to go shopping for a new one. Which was kind of fine since that scale wasn’t great. But finding a good scale turns out to be pretty hard! In the end I found some review that compares different scales and as a reference they used an entry-level lab scale. So I figured, hey, why don’t I just buy the benchmark scale? It costs about the same anyway. So now I have an ugly German lab scale that actually has an off button and runs on a 9v battery. Here’s hoping I never have to buy another.
- bombcar 4y agoThis is the secret for lots of these things; if you step slightly above “home use” you can often find industrial/commercial products that will work just fine - though do be aware of the limitations in some. Or you could go with fully mechanical balance scales.
- bryanrasmussen 4y ago>Strangely enough none of our kids toys with batteries seem to suffer from this problem we have some toys around where the way to turn it off would be to unscrew the battery compartment and take out the battery. The toy cuckoo clock that the kid broke that now goes cuckoo at odd times was fun, but hmm, nobody can seem to find it in the house anymore, wonder what happened to it.
- Cthulhu_ 4y ago> electronic caliper: Same, eats up 1 button cell a year, just sitting in my toolbox ooo a chance to plug one of my favorite youtubers; I believe it's this video [0] that compares cheap with expensive / brand digital calipers; the TL;DR is that the expensive ones use much less when off, or, the cheap ones use 4x as much. They both keep using power when off though, so that when you move the calipers while off it will still measure the distance. [0] https://www.youtube.com/watch?v=KnDype-j3hk https://www.youtube.com/watch?v=KnDype-j3hk
- nrp 4y agoThis seems to be common in battery powered test equipment. I have a decade old Fluke multimeter and five year old Mitutoyo calipers that both seem to be powered by magic. Neither has needed battery replacement despite regular use.
- reticulated 4y agoOur kitchen scales have a single on button and auto power-off after a minute or so. I discovered completely by accident that holding the power button down for 3-4 seconds powers it off. Nowhere in any of the manuals was this mentioned (I went back and checked)
- LorenPechtel 4y agoMany devices will turn off when you hold the power button long enough.
- rightbyte 4y agoMaybe a rouge engineer added it for the benefit of mankind?
- lultimouomo 4y ago> electronic caliper: Same, eats up 1 button cell a year, just sitting in my toolbox Had the same problem; got a good Vernier caliper, never looked back. Some things just don't need batteries!
- mod 4y agoI did the same! And now every time I go to use the thing I have to look up how to read it again. I don't do highly accurate work very often, obviously. I don't like buying non-rechargeable batteries, though, so cell batteries are out.
- IshKebab 4y agoI agree. They're not difficult to read but they're definitely more of a pain than replacing a battery once a year. A dial caliper is better than a vernier caliper anyway. Still more of a pain to read than a digital one.
- pards 4y agoI bought an RF pet tracker last year that comes with rechargeable CR 2032 batteries and a charger [0]. The rechargeable batteries factored highly in my decision-making process. [0]: https://www.girafus.com/en/products/charger-batteries/ https://www.girafus.com/en/products/charger-batteries/
- ClumsyPilot 4y agoAlso one sold by the Pi-hut: https://thepihut.com/products/lithium-ion-coin-cell-charger https://thepihut.com/products/lithium-ion-coin-cell-charger After someone nicked my electronic calipers, I also got mechanical ones - they are perfectly adequate for all home use so far. I used to use electric ones for 3D prints and designs, and haven't tries that since - might not be able to get the same perfect results with mechanical ones.
- lobochrome 4y agoRegarding Kitchen Scale: I recently bought this [1]. It works with friction - you turn the nob once or twice and you're good to go for a couple weigh ins. It feels rather cheap - so let's see if it really lasts. I love the idea though. I wish we had more energy harvesting gadgets like this. [1]; https://caso-design.de/en/p/caso-kitchen-energy-design-kitchen-scale-batteryless/ https://caso-design.de/en/p/caso-kitchen-energy-design-kitch...
- stinos 4y agoHave had a similar model for like 5 years now. No regrets yet. The small effort it takes to power it up by far outweighs all of the disadvantages of a battery. Before that I installed a switch in the scale we had to erradicate battery drain.
- bombcar 4y agoSince scales inherently involve putting weight on them it should be possible to use that weight to push down a plunger generating enough electricity to run for the weigh-in. A spring would then reset it for the next time.
- BenjiWiebe 4y agoIf there's a plunger resisting the scale going down to harvest energy, that would prevent all the force from being on the load cell, giving you incorrect readings.
- hundchenkatze 4y agoCouldn't you subtract the resistance of the plunger and display the adjusted value?
- shkkmo 4y agoNot if the plunger rests on the load cell. Then plunger just captures the work done as it is compressed, it doesn't reduce the force that passes through it (once at equilibrium.)
- 4y ago
- birdman3131 4y agoAll of those are ones I would argue the best design is to eat a few batteries a year. Calipers need to hold memory specifically. But more generally most of those are using alkaleak batteries and you really wanna be changing those out on at least a yearly basis. So it actually makes since to let them have a small always on drain. (Some might be using a 2032 lithium but I can almost guarantee at least the calipers are a 357/lr44 alkaline battery.)
- Retr0id 4y agoMemory of what?
- mod 4y agoProbably which position the zero is at, and maybe which measurement system you're using.
- regularfry 4y agoThe zero set-point, usually.
- jsjohnst 4y ago> Calipers need to hold memory specifically. You don’t need power to retain a tiny bit of settings data. I believe the real reason is because most of them have the “helpful feature” of turning on when you move it. Without something monitoring the sensor, no way to know to turn on automatically.
- NavinF 4y agoNo, most calipers can only do relative measurements. It’s constantly counting how many 0.01mm the head has moved so it doesn’t lose track of where 0mm is located. Turning on the LCD when the volatile counter changes value is a free feature since the mcu is always on. Of course better calipers do absolute measurements, but they’re too expensive to scribe lines with and therefore useless for hobbyists.
- _trampeltier 4y agoWhen started to live in my own appartemen and was the first time sick, I bought a thermometer to measure fever. The second time when I was sick a couple of years later the battery was flat. So I bought an oldschool thermometer without battery to measure fever. I use still the same 20 years later. Of course it does take a bit longer to know your body temperature, but when you are sick, you are not in a hurry anyway.
- parenthesis 4y agoWhat's wrong with mechanical bathroom and kitchen scales?
- dividedbyzero 4y agoI tried to get such a kitchen scale and couldn't find one that wasn't either highly imprecise or ridiculously expensive (like three digit euros) If you have a vintage one that is reasonably exact, they're great.
- ilammy 4y agoYou cooking meth there or something? It's a kitchen scale, I doubt you'd need that much of precision from it.
- zimpenfish 4y agoI use the kitchen scales (and a smaller set of digital scales) for measuring out things like resin where you do need a reasonable degree of precision, especially when you're measuring out small amounts e.g. 5g of A and 6g of B.
- ClumsyPilot 4y agoyep, also been doing that, mixing epoxy requires good accuracy. that being said, UK police considers kitchen scales as evidence that you were dealing drugs
- dividedbyzero 4y agoEver tried baking with some of your ingredients 20-30% off? Doesn't work well for lots of recipes. What's even worse is when the error isn't a linear x%, but changes with increasing weight.
- GekkePrutser 4y agoMy caliper eats at least 1 battery per month and it's those awful R44 alkaline ones that start leaking when they're empty :(
- lapsis_beeftech 4y agoGet Vernier calipers! The scale is easy to learn and use and measurements will be at least as precise as electronic calipers. With no batteries required the tool has much less of an environmental impact and you never need to worry about whether the calipers will work or not.
- jrockway 4y agoIt's just the cheap no-name calipers that eat batteries. Genuine Mitutoyo (and probably similar brands) treat their batteries very kindly. I have used vernier calipers but the time savings of not having to scrutinize the vernier scale every time you take a measurement is quite worthwhile. Just buy a good set.
- benhurmarcel 4y agoThere are also calipers with a dial. https://www.otelo.fr/waroot/images/products/600/40130350_A.gif https://www.otelo.fr/waroot/images/products/600/40130350_A.g...
- mlatu 4y agoit doesnt even have to be a mitutoyo to get you down to 0.01mm precision, i got mine for about 40euros. Using equipment i had access to at work i checked that rating and indeed: the tool i got is good for measuring at that scale, and you really dont need any electronics. Usually you can pay the vendor to calibrate the tool for a couple bucks more. of course digital ones are much, much easier to read, but you only really feel that convenience when having to measure hundreds of items quickly to sort them into a tray or something... And in the end, usually a Nonius type caliper is good enough anyways, and skilled users can read those to up to 0.02mm... and thats already pretty good and most of the time: good enough and in case you do need to know the length of something down to a micron, there are other tools for that with less sources for measuring errors so yeah: mechanical calipers rock and: you dont have to always get the brand things to get what you need
- convolvatron 4y ago
- HPsquared 4y agoIt comes down to the electronic design: specifically, low current draw when "asleep". Obviously it's possible to make electronics that costume a tiny amount of power (think quartz watch that lasts for years with a very small button cell). It's just poor workmanship by the designers or penny-pinching.
- Robotbeat 4y agoSomeone at my work has a really nice electronic calipers that is solar powered (think like a calculator… low enough power requirement that ambient light is more than enough) and thus will effectively never need battery change.
- LorenPechtel 4y agoMy wife has a calculator that is solar powered--unfortunately, the light requirement to reasonably use the calculator is lower than the light requirement to run it.
- ClumsyPilot 4y agoThat is really clever, should really be used more often. When it comes to kitchen scales, most Kenwood food processors double as very accurate and premium kitchen scales with backlight, as as they are plug-in they don;t need battery - great option if you have the counter space - you just place a platform where the chopping bowl goes. After someone nicked my electronic calipers, I got mechanical ones - they are perfectly adequate for all home use so far. I used to use electric ones for 3D prints and designs, and haven't tries that since - might not be able to get the same perfect results with mechanical ones.
- ddingus 4y agoNice! I never thought about a solar powered model. I may have to try one next time I am shopping.
- hitovst 4y agoThis doesn't cover all the unwanted surveillance tools we pay to have spy on us.
- ClumsyPilot 4y agoI try to avoid coil cells in all my devices - all batteries in my house are rechargeable. That being said, there are rechargeable button cells and there is a button cell charger! https://thepihut.com/products/lithium-ion-coin-cell-charger https://thepihut.com/products/lithium-ion-coin-cell-charger
- kazinator 4y agoI bought a Yamaha FX-500 processor in 1989. 29 years later, I did a mod to convert it to a batteryless NVRAM chip. The original button cell battery was still good; settings I last touched in 1990 were still being held. Garage door openers can last 10-15 years too; those use the battery to transmit a signal, not just to hold a piece of SRAM alive. The bathroom scale is just a poor electronic design.
- rekado 4y agoMy digital bathroom scale doesn't have batteries; it has a big capacitor and a foot-operated push-button that charges it. I tap the button maybe three times and that's enough energy to use it. It was also dirt-cheap.