I wonder how it worked. I mean, not the obvious answer which is that it fucking didn’t. But how it was supposed to work.
There is a metal strip inside that gets narrower on one side and as it gets narrower the resistance increases and once you press both sides it gets in contact with the battery terminals and current flows through. The lower the remaining battery capacity, the less the wide part of the strip heats up. Over the top is a heat activated colour strip thingy that shows how much of the strip is heated and thus approximately how much juice is left in the battery.
Lol, so checking the battery actually used up some of the remaining juice?
always has been.
To measure is to change —science class
If it didn’t use power, it could remain on all the time.
There is pretty much no way around this. All voltmeters use power (although digital ones use their own source and draw very little from the measured voltage) but this one consumes more than most.
I think they could make one with some LCD or electrochromic display (both use a negligible amount of power) but it might be too expensive to include on each battery. Also, the voltage to state-of-charge relationship is not a simple one: discharged batteries’ voltage will rise back when not in use but the internal resistance had gone up so they no longer allow discharge at a practical current. The little heater test accounts for this, an LCD or ECD does not.
Isn’t that obvious? How elae would it work? Its not like electricity is like a fluid you can check the level of.
It actually did work reasonably well I always thought, but only if you did it just right. It was more a gimmick than a feature IMO - rarely did we keep batteries long enough to wonder if they were dead, and we usually determined it by putting them in a device.
Yeah, worked for me too, tho my dad had a device to measure how much a battery had left so I nvr really had to destroy my fingers
Why do people keep saying that they didn’t work?
- They work just fine for me. Never had an issue
- They’re still a thing, so what’s with the past tense?
I think it’s because many people misunderstood how to use it: you’re not supposed to jam your thumb on the sharp corner, rather just gently push on the flat end.
Huh, I haven’t seen these things for many many years. And thought about them a few months ago and actually just bought a battery tester / charger. I don’t think they exist in Germany?
I remember seeing these within the last decade back when I still lived in Latvia
Edit: After quick Google search, they still sell this type of battery, Duracell MX 1500 and MX 2400
Haven’t seen one in Australia in about 10-15 years
Were a thing in Italy I think in the 90s. Don’t live in eu anymore but haven’t seen one since.
They did work fine, it was just incredibly painful, and took a very long time to get a reading. Gee I might have just made some progress with my therapy.
What country are you in? These were a gimmicky thing in the late 90’s that went away in the early 2000’s ish at least for us in California.
Southwest United States. See them being sold all the time in grocery stores.
As a nail biter, the lack of nails made them hard to use forme, but I guess they’re better than nothing.
Thankfully rechargeable batteries and much better now, and a separate battery tester works better IMO.
Why do people keep saying that they didn’t work?
Honestly, I’ve never heard of theses things until now.
I’d wager at least 50% of the 66 people who upvoted /u/amio haven’t heard of it until now, either. They just upvote things because other people upvote them.
You squeeze the battery pushing the power juice into the meter. Trust me, i’ve eaten alot of batteries.
/s
I think I still have the dents in my finger.
This thread hurts physically and emotionally. Why did you choose this violence today?
I remember fake Duracell batteries with only picture instead of a real gauge. I really feel the pain.
The people who didn’t use their fingernails to press it ☠️
These were helpful in a pinch, no pun intended.
If you had a better option, then use it. I’ve put these things into testers because they’re too darn annoying. If you don’t get a reading, you have no idea if the battery is just dead, or you just screwed up making these fiddly things work.
I’m not a big fan of alkaline batteries in the first place, and the rechargeable ones are great to use in medium and high drain devices that are used frequently, but for anything that’s low drain or sits for a long time without being used, the batteries tend to drain themselves faster than they get used. Even if the device is completely off.
I vastly prefer any form of lithium over most of the intermediate rechargeable technologies.
If it’s a 9 volt or watch battery I just lick the terminals
I had a bad habit of touching the negative pole of a AA or AAA battery to my upper lip, and the positive to my tongue, and you can feel a bit of current and sort of gauge how much charge the battery had. One day I saw this mini battery for a camera just laying around. I did it without realizing it was an A23 12 volt camera battery. I literally saw lightning in my eyes and never did that again without making sure I wasn’t going over the usual 1.5 volt AAs.
Edit for clarity
I was installing lights once on a stepladder. Asked my girlfriend at the time, “can you switch off the fuse for the bedroom?”. “Sure thing!” was the reply. I got a massive jolt that spread down my body and rattled the ladder. Somehow didn’t fall. Just stepped down and processed a few things.
Lights were on the fuse marked “lights” and she switched off the wall sockets?
so it was a misunderstanding between “sure thing” meaning “I’ve already done it” and “sure thing” meaning “I’m on may way to do it”
It’s still the best way to determine if it has charge and how full it is and nothing will change my mind.
I can still feel the awkward crunch of subcutaneous fat under my fingers… 🥲
Do they still make those portable power strips for checking batteries? Those were so handy instead of having to use a multimeter.
edit: these little flexible strips:
I got this device when I bought a battery case while switching to chargeables. In bulk they cost about 1,- , so, 5.99 at your favorite DIY store?
Look there it is, in the middle!
Honestly, I’d rather the analog screen that yours has over the digital one I posted. They just tend to hold up better to sitting in a toolbox for a couple years
I just use my multimeter, but im a crane technician and have several very expensive ones and my wifes an electrician so its not uncommon for a multimeter to be nearby
what do you do with that many batteries
Slowly switching over every battery in my house to one that is rechargeable! Lots of old single use batteries rocking on, motion detectors, temp detectors, remote control, bike light… It adds up quickly and I’m not swapping batteries that haven’t died yet.
Toys. So many fucking toys.
Daddy’s got it
I’ve got an analogue version of that. Absolutely fucking useless it is. Every device seems to have different thresholds for acceptable levels of power.
It depends on the chemistry. All battery chemistries have different discharge curves. So if you use an alkaline tester with, say, a NiMH battery, it’s going to give you some pretty inaccurate readings.
I got one a couple years ago for Christmas. Guess you can still buy them from those mail order catalogs…
But I use it all the time! It’s so handy.
Could anyone explain it to me?
Batteries use to have a power check mechanism.
There was a small white circle on the copper top side and a half circle on the bottom non nipple side.
What you needed to do was cover the white circle on side of battery with a thumb and then cover the whole bottom with other thumb and the indicator would tell you how much the battery had left.
Since it was a half circle off the bottom many people didn’t know they were supposed to cover up the whole bottom. Making it hard for many to use it because you’d have to press down very hard on the edge to get it to work.
Thanks 😄
They still make these I think. I swear I saw some not too long ago.
I have some in my closet. They’re still good, I checked them yesterday!
I never used these because of the price. What did they do? Or maybe more to the point, what were they supposed to do?
If you pressed your fingers on the designated spots, it was supposed to tell you how much juice the battery had.
But you REALLY had to press down, and it was unreliable and painful.
Or the pain of having to do percussive maintenance to get them out of tight-fitting battery compartments? I remember those constantly getting stuck in my little Mag-lite.
They still bring these back every now and again. They just did like 5 years ago.
I never had trouble using these other than the few times it burned the fuck out of my fingertips for some reason.
I’ve been using Ni-Mh rechargeable batteries for a lifetime now. I keep em charged, I used them for portable cameras and other devices but now they’re only useful for the electric razor. Still, they save a lot of batteries that i’s otherwise throw away.
My mom bought a bunch of rechargable double and triple as and a charger, and we used them my entire childhood. My friends were always in awe whenever my gameboy died and I didn’t have to search through a kitchen drawer (or the freezer) for half dead batteries.
