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.
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.
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.
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?
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.
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.
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?
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.
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