Duracell PowerCheck: A genius idea which didn't last that long

[@TechnologyConnections]

A note on current: The tester's behavior (how much of it turns yellow) is also dependent on how much current the battery can provide, but how exactly that was calibrated is... fuzzy. I only discussed voltage here because the original Kodak patent describes it as a "Battery voltmeter" and my first test with the DC power supply was consistent with this video's script. However, when I was filming B-roll with a second unwrapped battery, it was passing much more current than before and I needed to limit current via the power supply for it to show a clean cutoff in color. At just 1 volt much more turned yellow than in my first test, and over a smooth, spread-out gradient. I sort of suspected this (that weak batteries would pass less current, compounding the effect of the heat gradient) but I couldn't back that up with anything concrete. My first test probably had a poor connection between the power supply leads and the label which was limiting current enough to make voltage the only significant variable, but until I filmed it with the second battery I didn't know it was pulling less current than it otherwise could.

[@eduards2790]

For future refrence, got a little confused at 7:50 becuase what is stated in the audio does not match what is shown in the video.

[@Glaaki13]

as kid I had old batteries as they could play a song or to after a time off in the draw

[@truckerallikatuk]

It's probably a printed carbon film resistor, often used on inexpensive devices as it's pretty much a thick ink that can be printed onto a surface. Edit: They may have been easy to print, but they were often HIGHLY inconsistent in thickness especially with low cost printing methods. This would explain the inconsistencies you (and we) experienced.

[@petervolz493]

A battery is commonly modelled as a constant voltage source with a resistor in line. Resistance is rising with emptying it.

[@markthompson4567]

depends on what you use the batteries for my mouse use batteries and it becomes laggy and not great to use but then same batteries in a TV remote work just fine so i do keep them for later use

[@swedtwo]

Nothing like making your fingers white with pressure trying to get a reading from these guys.

[@piuthemagicman]

that's what nails are for, thanks to evolution

[@jrrarglblarg9241]

…and realizing the tester is a resistive load, eating the battery…

[@RedWingsninetyone]

​@@piuthemagicman That includes nails

[@OrangutanKiwi19]

And feeling the battery get uncomfortably hot in the process

[@monetary_episode494]

My fingers are already white tho...

[@moertelruehrer]

That was truely a throwback for me this evening. I had these when I was a kid in the 2000s and always wondered how they work. Now, 20+ years later, I'm sitting here with a PhD in physical chemistry, saw these and immediatly knew what was going on. The satisfaction when you explained it really made me smile. Thanks from Germany!

[@MrAtomek321]

You can still buy those batteries in Germany

[@CyberUtilia]

I figured it all out the moment I read the "test at 70", up until the heating element having to be a gradient (though I guessed it would be becoming thinner, but they used a more space-efficient design by making it just go narrower instead). It was satisfying to still hear about all the smaller features that optimize it, which I couldn't have thought of, but make perfect sense. They tested it in real-life, they found ways to do it best.

[@newq]

I was just thinking the other day about how I don't see these anymore! I remember playing with them as a kid so much that I'd run the battery down just by checking the charge so much lol

[@mothmansuperfan7513]

Just opened my Furby and was met with a Duracell Powercheck. Thanks for answering my thoughts!

[@squirtle88]

lmao

[@pluto8404]

were the batteries still charged?

[@CopenhagenDreaming]

That just opened a whole can of emotional worms for me... My ex - if we can even call it that; we dated for 2 months in 1999-2000 - called me his furby. Ironically, as I am not very hirsute by nature... I should really give him a call, shouldn't I?

[@Whammytap]

Your diction is so precise, so perfect. I'm grateful for the outtakes; if not for them, I'd be convinced that your oration skills are superhuman. As a person with (self-inflicted) hearing loss, your channel is so pleasant to listen to.

[@mpbx3003]

I genuinely wonder what the rate of self-selection is between past kids who loved testing these batteries and adults who are fans of the channel. I assume quite high. I'm surprised there aren't any rechargeables using these currently. I suppose chargers have testers built-in, but it would be neat to have it on there. [Partially, if not mainly, for nostalgia purposes.]

[@lohphat]

My generational split was that in the '70s as a kid I saw tube testers disappear from Radio Shack.

[@smalltime0]

It's likely because the voltage drop off from a rechargeable cell is more sudden than a standard alkaline one. It'd still work, just nowhere near as reliably

[@volvo09]

​@@lohphatin the late 80's the electronics shop my dad got TV transistors and whatnot from still had a tube tester. I was probably 7... I had a tube B&W TV which I thought was cool.

[@anezay4987]

I feel seen. Stop seeing me.

[@Pickleriiiiiick]

Checking in on the testing of these to oblivion as a child!

[@sypwn]

They still make PowerCheck batteries under the Duracell Quantum line. I'm holding a pair right now that haven't expired.

[@ESSBrew]

Thats what I thought, I totally have new ones in my house.

[@squirtle88]

its a pretty pointless feature but so cheap to produce they might as well keep them around!

[@tartarughaninja4]

duracell turbo here in EU... i have a box of these.

[@hustla818]

I made a comment stating the same. I bought a whole box of duracells that had the battery check on them just a few months ago. Still have a bunch of them left.

[@smashed_penguin]

Same, but under the Duracell Ultra product line here in ZA. Also still has PowerCheck™ on the label.

[@ChrisPlaola]

In Canada, we had these into the 2010s. I remember being fascinated by them. The ones I grew up with (2000s - 2010s) had blue indicator bars, and some of the most recent ones actually had muti-colour indicator bars.

[@DerivativeOfLog7]

Same in Italy, I remember seeing ads for them when I was in elementary school, so that would be around 2007-2013

[@luckycobble935]

I'm in the United States, I have used new in package from store batteries with the indicator. They weren't Duracell but still...

[@TheWitchAndromeda]

Same in Australia

[@VanillaLibrarian]

Yep, I was surprised to hear "late 90s". I don't remember these being common in the Netherlands until the mid 2000s. Most of them had a yellow indicator, but I vaguely remember encountering a few blue ones towards the end of their tenure.

[@artuto55]

Yep! Here in Mexico we had these until the early 2010s and they were blue as well, thought I was misremembering when I saw the ones in the video were green.

[@DeviantOllam]

Anyone remember the commercial with a whiny child? "His toy has stopped... and he has started. You know you've got a spare battery in the drawer somewhere, but is it any good?" (Then the Duracell power check feature was revealed to the public) Ah, memories! 🔋

[@Pickleriiiiiick]

Woah, subscription crossover from an unlikely combination. Love your videos man!

[@Pickleriiiiiick]

Actually the likelihood would be high so I'm not surprised, nerds nerd on the same nerdings.

[@hateeternalmaver]

No but I remember all the cheap-knockoff batteries "having one" which actually never worked. =D =D

[@FlesHBoX]

And now I'm wondering if there is a way to exploit these batteries to gain access to something, lol

[@bkw67]

Love when one of my favorite KZbin channel hosts comments on another of my favorite channels!

[@celik4669]

you have no idea how much i needed a TC video right now. thanks

[@spv420]

life gets better -- eventually and sometimes it doesn't sorry if this didn't help

[@hinnahinna-j9y]

My mom has a battery drawer with old and new batteries all mixed up. She says PowerCheck is wrong, they are all still good. Aunties ignoring them is why they go away. I will be inheriting those batteries in 30+ years.

[@TheGoatstep]

They still make em, or at least they still did in the past 5 yrs here in the UK 🇬🇧 - I’ve got some Duracell AA’s and AAA’s which I bought brand new within the past 5 yrs that have the PowerCheck bar on them

[@TheGoatstep]

I just checked eBay UK - and found some AA powercheck’s with an expiry date of March 2029 (so probably made in 2019 since I think they usually have a 10 yr lifespan when unused) - though there’s only 3 listings for them, modern AA’s with powercheck usable til 2029, and some vintage AA’s with powercheck as a collector item

[@MarcPlanard]

Came here to say that. Bought a fresh pack of those not 2 years ago in France.

[@pauldriscoll5010]

Yes Duracell ultra still have them on as and aaa in the uk

[@katrinabryce]

None of the Duracells currently for sale in Tesco have them, but yes it was around until pretty recently, I think. I've only ever bought rechargeables, so I'm not sure.

[@Alexander_l322]

I was thinking the same thing but I haven’t bought power check in ages!

[@rgsteele]

I remember as a kid wondering whether the gauge was heat-activated, and confirming this was indeed the case by activating the tester while holding the battery against my upper lip and feeling it become pleasantly warm.

[@benespection]

Wow, me too! I mean, I used my lower lip, but it was fascinating. I'm glad I'm not the only one :) The colour change occurred in such a "blotchy" way that it looked so similar to how thermochromism in Hypercolor t-shirts and liquid crystal thermometer stickers for aquariums worked - this is what made me also come to the assumption it was a little resistor acting as a heater underneath the label, so I also tested it against my lip. Crazy.

[@tomgidden]

As others have noticed, they're still available in some countries. It's been a long time since I bought Duracells -- in my experience, they're far more likely to leak than, say, GP brand -- so I don't know when the feature left the UK, but it must've been since 2019. I'm not sure if the patent issues had anything to do with it, but I reckon it's more that they were an obvious value-add to try to distinguish them as premium choices over their competitors. With the reduction of demand and places like Amazon selling massive packs of generic AAs very cheap, they became a truly-fungible commodity and reducing cost became the priority. They were probably removed gradually from low-end to high while they desperately clung to the few clueless customers that'd buy top-end retail for their remotes, before gradually surrendering and being progressively removed from DURACELL PLUS, then DURACELL ULTRA, then DURACELL OPTIMUM, and finally DURACELL HYPERBOLE and DURACELL REALITYWARP or whatever they're called now.

[@Pickleriiiiiick]

I remember dissecting these as a kid trying to figure out how they worked. Thanks for this, core memory of being technically curious! I do recall specifically that the strip would be warm to the touch after messing with it.

[@Malog.]

I still see many Duracells with there tester things here in Hungary, they are not super common but also not impossible to find.

[@sokrates297]

Really appreciate you pressing that hard just to illustrate the real struggle it was to use these, even tho you didn't have to! 💜

[@EilonwyWanderer]

Always neat to see current tech talked about -- I mean, it's not *current* current technology, obviously, but I was certainly amped up when I saw the title and thumbnail! I'd wondered how these things worked back when they were new, and it was fun learning about it. 😁

[@MintyVoid]

this is so cool!!!! I was utterly captivated by these as a kid even tho I had a volt meter in the house- I just loved checking batteries with the dots. So cool to finally know exactly how it worked.

[@glonch]

At the first test, I was thinking - A. I don't remember them working that fast. B. Hey wait, those should be long dead, how did he get it to work... Sneaky...

[@hustla818]

I knew it was bs because he wasn't pressing hard enough 😂 you have to press insanely hard for it to work

[@plenet]

Here in Europe those seem to be still a thing. I grabbed some out of my drawer (best before 2025), and they have even diffent colored sections now! red/yellow/green. A quick measurement shows, the indicator draws quite a lot of current: at 250mA barely visiblle, and 500mA shows full bar.

[@RicArmstrong]

What brand in Europe makes them?

[@yoranbosman3565]

Yeah duracell still sells them here

[@s2000.]

Exactly what I thought, I remember the red yellow green Duracells and I'm not that old yet.

[@SemiHypercube]

oh hey I remember those things, even if it was pretty hard to actually use it still was pretty cool having a way to test batteries on the battery itself

[@TheTarrMan]

I miss when they used to build the battery check thingy into the actual packaging the batteries came in. This was more like early 90's era. The ones wrapped around the battery like what you showed never worked very long for me. I think Energizer made a version of that too.

[@volvo09]

Oh yeah I totally forgot about those! I cut one out as a kid and it was my tester, collecting and filling boxes of batteries for my game boy.

[@pistonburner6448]

We had a separate battery tester, which tested all typical batteries from AAA to 9V

[@kathrynradonich3982]

Yup I remember these too and worked pretty well without destroying your fingers in the process

[@JL-db2yc]

Yes, the testers in the packaging were the ones I remember Duracell had.

[@lexicon1580]

This is fascinating! I remember these from when I was a kid but never thought about how they might work.

[@volvo09]

I took a few apart as a kid to figure it out :) haha

[@MichaelSteeves]

Late 90s? I just found some of those in something the other day!

[@szimre95]

Yeah I bought a set of Duracell batteries about 2 years ago for an A/C remote and they have this feature. Central EU.

[@volvo09]

Had they leaked?

[@earthboundman5]

I had Duracell Powerchecks in my cabinet just a year or two ago. In the United States. The new ones were red

[@blackman7437]

<a href="#" class="seekto" data-time="42">0:42</a> Wait, is that a PKCell?

[@yaboiminecraff]

What a nugget

[@benjamingeiger]

I still remember the handheld CB radio I had that took either six alkaline AA batteries or eight NiCd batteries, since NiCd cells only output about 1.2V. It came with two metal dummy cells that you'd put into the battery compartment when using alkaline batteries.

[@Travelinmatt1976]

I had a set of those too, with the dummy batteries

[@squidcaps4308]

My dad bought a Canon pocket camera some years ago. It used two AAAs. It goes dead if the voltage drops below 1.4V... Which means it eats batteries like Mr Creosote, and also that rechargable batteries when full don't always even turn the damn thing on. Would you be surprised that you could buy a battery pack from Canonr that has LiPo cells with incredible markup?... I sometimes wonder how stupid greedy people are. People don't buy expensive battery packs after being disappointed that not even normal batteries really work, they just stop using the damn thing and have suspicions about that brand forever. Electronically there is nothing that explains that, if the circuit needs higher voltage then there are simple little chips for that, costing single cents, in very tiny packages too that will raise the voltage so that you can use all the juice in the batteries. It will fit in the board, it does not cost a lot but... got to sell those battery packs i guess...

[@Mike-ukr]

@@squidcaps4308 Non-rechargeable lithium iron disulfide batteries are manufactured for devices that draw more current, such as digital cameras, where their high cost is offset by longer running time between battery changes and more constant voltage during discharge. from Wikipedia

[@richiehoyt8487]

​@@squidcaps4308 "People don't buy expensive battery packs after being disappointed that even normal batteries don't properly work"... Ah, yes; well, the way around that is you build your device to run on a non~standard voltage, or with special unique connections and/or weirdly shaped battery compartments so that _only_ proprietary power~packs will work. That way, the problem of consumers griping about the product's performance with standard, off - the - shelf batteries won't even arise!

[@PlayerSlotAvailable]

I remember those. I never noticed that they said anything about temperature! We used to put the batteries in the fridge so it would "recover some electricity".

[@196cupcake]

<a href="#" class="seekto" data-time="720">12:00</a> A big part is competing on brand loyalty. The brand and generic batteries are literally made in the same factories.

[@phlash65-5]

I actually wish more products would return to simple batteries like this. It makes it more convenient in a way, and it allows you to hold on to that device long term and still make it usable. I have loads of tech from the 90s that I can still use today by popping in a fresh AA battery, but I also have loads of now junk devices from just several years ago that won't work because the built in rechargeable, non-replaceable battery is dead and won't hold a charge anymore.

[@StephenSmith304]

I would love to see these make a comeback for rechargeable batteries. I think it would make more sense because the re-use of rechargeables makes it more likely to have half used or empty batteries around since you might just toss then in the drawer until you get the chance to recharge them.

[@jimmyzhao2673]

My sister's kids had so many toys that needed batteries, my sister would often say that she needs to own a battery store.

[@MrChuckGrape]

I miss those! I never trusted them, but I like seeing the line change colors.

[@adalaza]

These were utterly iconic, I loved these batteries.

[@hippyraverocker]

Through the magic of buying two of them...

[@aKadoki]

i cant tell you exactly when, but i was born in 2004 and sometime around me being 7 we got these batteries where i live. I was actually amazed at how this can measure it, i unwrapped it too but i was disappointed to see that it was so simple, i didnt know it was measuring temperature tho. This video brought back those memories.

[@riz94107]

Feel better soon!

[@RedWingsninetyone]

I'm excited for whatever video is having production issues. This is at least the second time I've heard it mentioned so it ought to be good when it is finally finished!

[@Dtr146]

When you said 1.5 volts, I had a twitch in memory of all of the troubles I used to go through with batteries not lasting long because they were 1.3 volt double A's and triple A's when the batteries that you should have been buying were 1.5 volt double A or triple A to get the money that you actually are paying.

[@volvo09]

You could often get packs of "heavy duty" zinc carbon batteries that were significantly cheaper than alkalines, but they couldn't deliver high current. Good for remotes and clocks, but if you used them in a toy they'd barely last. I believe they were still 1.5v, only batteries I recall being lower voltage were rechargeables. NiCd cells are 1.2v per cell, but they could deliver high current. Good for tou cars and stuff...

[@Dtr146]

@@volvo09 Yeah, until you buy one that says heavy duty and still is 1.3 volts. When you have a device that won't power on at 1.2, 1.3 becomes useless.

[@w0ttheh3ll]

My internal AA/LR06 SOC(V_0) lookup table was calibrated measuring so many cells. When I saw you test that cell at 1.57 my heart leapt with joy :D brand spanking new indeed!

[@tkscustomsupermodz]

<a href="#" class="seekto" data-time="673">11:13</a> Unless you have a BuddyL supercharger released in 1992. I remember having one of these and we were able to recharge and reuse alkaline batteries several times over. Geting rid of batteries wasnt a common thing when i was younger. I recently picked one up on eBay and i'm back to recharging and reusing these batteries. The battery testers were awesome when paired up with a supercharger!!! You should do a video on the supercharger!!

[@alexlefevre3555]

I remember this being such a cool thing as a kid. I felt like I was somehow a conduit through which some technology manifest itself to display the energy level of the battery. Great video as always!

[@ThatOneWeeb420]

I remember these. I actually still have test strips around that can be used on a AA and AAA batteries, although nowdays I have a multimeter and that does the job, and not to mention I have a good handful of eneloop pro batteries that are rechargable.

[@SilverAura]

This is fascinating because it also explains why I have vivid memories of my thumb feeling like it was getting warmer than just pressing too hard. But after too long, it physically became hot to the touch.

[@m_lies]

<a href="#" class="seekto" data-time="175">2:55</a> We still have the exact same Battery Tester just in Black

[@taffetatwist2194]

These were a mainstay of the Lego Technic experience throughout the mid to late 90's. Good example of moving partially used batteries around constantly - between builds / battery boxes etc. Just looking at them in this video is making my finger tips ache! Also served as babies first fuel gauge.

[@stopboorider]

I remember being a kid and NEVER getting these to work, even though the batteries were brand new in some cases. But also, even though I could read at the time, I didn't really understand the 70f degrees thing beyond "obviously don't shove the battery in the snow", and being very North growing up, in a household of people who ran hot, I don't know if these batteries ever saw 70f again after we bought them, as usually the house was kept around 60f. I don't know how much impact that might actually have on them, but between that and kiddo fingers, I can imagine the heater wasn't able to keep going long enough to light them up actually. DELIGHTED TO FINALLY KNOW HOW THEY WORK NOW BECAUSE I SURE ALWAYS WONDERED. side note, my ergonomic keyboard and mouse combo, the mouse uses AA and the keyboard uses AAA why. w h y. this is literally the only electronic in the house currently that uses AAA, and it sure is bigger than the mouse. WHHHYYYY

[@volvo09]

With childhood finger strength it took a LOT of pressure to get it to work, your fingers would turn white pressing so hard. It likely wasn't that slight temp difference, you just couldn't push hard enough. I had a lot of trouble with them (I think I must have been 6 or 7? Until my dad presses my fingers and showed me just how hard it was... I later learned to use my nail on the round dot and that helped a lot.

[@ericsmith6394]

Temp ranged from -25 F to 105 F (-31.5 to 40.5 C) where I was a kid and I gave up on duracell giving me a good answer. We got an analog test meter instead. It still works 30 years later.

[@naota3k]

Heck yeah, Alec. Shout-out to Prokaryotes!

[@Mountain-Man-3000]

Hell yeah. Loved that as a kid

[@rogerk6180]

We used to have a time where these testers where build into the plastic packaging. In the middle of a duracell 4 pack with cardboard backing. So you could test any AA battery by putting it between the contacts and pressing on the top and bottom with your thumb and index finger.

[@volvo09]

I had totally forgotten about that until I read a comment earlier. That was out when I was a kid and I cut it out and used it to fill up boxes of good and medium batteries for my stuff, haha

[@rogerk6180]

​@@volvo09 yeah, must have been in the late 80s or 90s. I did the same thing as a kid lol. Batteries where always a struggle because everything used to need them.

[@markmarkofkane8167]

I remember.

[@Roguescienceguy]

My guilty pleasure is technology connections. I am not gonna lie

[@izimsi]

TV remotes already use so little power, they can afford using AAA, as they will probably die of old age before they use all of their capacity. Using AAA instead of AA makes the remote lighter and less prone to damage when inevitably falling from your sofa or table, hitting the floor.

[@rhaedas9085]

I was just thinking the other day how long it's been since I had to put new AAAs into my wireless keyboard I'm typing on now. Like years...I imagine even on a busy session there's not a lot of charge being used to broadcast within its limited range.

[@orppranator5230]

Meanwhile my remotes lose signal strength as the batteries go down, which apparently happens quickly.

[@Skiman__]

Weight is a really good point. Two AAs really make a remote pretty hefty. I’ve even seen people put AAAs with a foil ball at the end in a AA slot so the weight is reduced, I’ve been thinking to try it but don’t because I’m lazy lol

[@seraphina985]

@@rhaedas9085 Yeah things like keyboards and remote controls need very little power as they don't have to do any really processing the biggest drain is generally going to be the LED or radio used to broadcast the signal. Meanwhile your wireless mouse will eat AA's for breakfast if you use it frequently as it's processing is quite a bit more complicated.

[@st.m.3979]

New Samsung remotes are battery killers. They eat double As for breakfast

[@PunakiviAddikti]

Interesting design. Just a small heater with a photochromic thermometer pasted on it. I remember these from my childhood, they were super useful!

[@natthecatgirl]

ooo, this sounds interesting!

[@OurHeroXero]

Love the NES cameo (<a href="#" class="seekto" data-time="235">3:55</a>)

[@OurHeroXero]

Okay, there are other shots...but who really wants timestamps for all of them>

[@five-toedslothbear4051]

How about C batteries? D? 9V? I had little tiny toy cars that ran on N batteries.

[@AaronOfMpls]

9-volt batteries, I've sometimes tested with _very_ brief touches of my tongue across the contacts. Strong tingle = good battery, weak tingle = (nearly) dead battery. On a different note, growing up we eventually had a plastic battery holder, hanging on the side of a cabinet. It had a bunch of round holes for different-sized batteries from AAAs to Ds, some rectangular holes for 9-volts, and a tester under a flap in the top left corner. (Though the tester used LEDs for its readout: green = good, yellow = low, red = practically dead. 🟢🟡🔴) Still, I do remember the on-battery testers as kinda cool, if ultimately not very necessary. And yah, the similar in-pack testers _were_ easier to use.

[@volvo09]

I think those N batteries were just a roll of coin cells... I remember having to find one for some remote? I can't remember, but radio shack had it! Must have been a tiny car, unless I have the wrong battery in mind.

[@ankaka222]

As someone who keeps loose batteries around (I use rechargeable batteries with my Xbox controllers. I haven't had to throw a single battery in the last 2 years), a battery tester is a very useful tool for me which I keep in my battery drawer. Great video as always!

[@fwiffo]

I have a label maker that doesn't just take AAA batteries instead of AA. It takes *six* of them. Six. A small change to the form factor and four AA batteries would take up less space and probably last longer. It's unfortunate that we've converted a lot of devices to built-in, rechargeable batteries, but then treat those as disposable. People get disposable nicotine inhalation devices, and then just toss them on the sidewalk. They have rechargeable, lithium-ion cells! Not only is it wasteful litter, it's extremely unsafe!

[@wernerviehhauser94]

Yeah, but that would result in 6V instead of 9V.

[@haxboi5492]

​@@wernerviehhauser94 Well you have 9V batteries

[@rogerk6180]

6 batteries means it runs on 9 volts. 4 means it runs on 6 volts. So it would need 6 AA batteries to function.

[@rogerk6180]

​​@@haxboi5492 9 volt batteries just have 6 AAA's inside the casing. Edit: they actually have 6 even smaller AAAA batteries in them ;)

[@jsax01001010]

​@@haxboi54929 volt batteries are even more expensive and have less capacity than 6 AAA batteries. A 9 volt battery is just 6 AAAA (yes quadruple A) batteries wrapped in a shell and soldered in series.

[@jimmyzhao2673]

As a kid, I would sometimes take apart a 9v battery to get the 6 tiny little 1.5v cells inside.

[@RickLaBanca]

<a href="#" class="seekto" data-time="453">7:33</a> you meant low resistance (high current)?

[@GregMcNamer]

The current across the entire strip is the same, but you get more current per unit of surface area as the strip gets narrower.

[@GregMcNamer]

I think his description of the mechanism is somewhat flawed.

[@lifeincycling]

Came here to say this.

[@discordinc]

I both remember the power tester batteries and using them. As a kid i remember testing them to see them fill up. Good to learn how they work

[@timderks5960]

It's pretty insane that this is more nostalgic to me than something like old games consoles, old PCs, old TVs, or virtually everything. I remember these so vividly, and I remember some point where I thought "Hey those aren't around anymore, what gives?". And with my memory, me remembering something like that is pretty unique.

[@pleappleappleap]

Yay! A new Technology Connections episode!

[@gydo1942]

Maybe those were a thing for longer in Europe, I remember these and I definitely wasn't around in the late 90s. I found it a fascinating gimmick and always figured it was going to be a heating element because of the test-at temperature, but always wondered how the bar graph would have worked. so thanks for explaining! Also yes I remember pushing my fingernails into these until they hurt to get the thing to show any life lol.

[@SebastianFool]

Came for the information, stayed for the outtakes. Great video as always.

[@Alexis-lt3zy]

I've seen these occasionally-- they're really neat! It's very, very useful to be able to check if a battery is charged without using a tester (or multimeter, if you're me)

[@w0ttheh3ll]

Duracells are not so common in Europe, but I remember these. Every time I got one in my hands I would try the tester. Not a single time was there any visual reaction whatsoever. I pressed my nails in there as hard as I could. Your footage is the first time I see what was actually supposed to happen.

[@MiniMackeroni]

I remember as a kid I loved these things. Since my parents were pretty frugal when it came to batteries, I switched my batteries around for any toys that needed them. And I remember basically destroying my fragile kid fingers trying to see the little bar appear and checking each battery. Especially since as batteries start to get used up, the voltage got lower and thus the toys got affected. So I started rationing the better batteries for my "better" toys. The kid version of swapping around the wheels of your car.

[@RiehlScience]

I loved those things! I haven’t seen them in years

[@squidcaps4308]

I once had excellent use for these. Was doing an outdoors show with wireless mics in the winter and we burned thru batteries at an incredible pace, typically they lasted over 3 hours but in the Finnish winter you were lucky to get 45 minutes and that was with the beltpack as close to human body as possible. Most of them just were too cold and once they warmed up they could be re-used a second time in the rehearsals. Powercheck® was awesome for those, didn't have to keep track of batteries and could just check before inserting them to the transmitter.

[@mymusic3354]

I remember these. It seemed like a good idea, nice to be able to check the charge without having to use a multimeter or something like that.

[@sguttag]

There is another reason. Back when the Power Check was in mass production...the "Maglite" was all the rage in flashlights. The AA version was VERY popular. However, the extra diameter caused by PowerCheck would cause the battery to jam into the flashlight. Duracell was, therefore, avoided for those flashlights. PowerCheck was a negative selling feature for one of their intended markets.

[@therealvbw]

These were available at least well into 2017 here in the UK, they had a red-yellow-green colour coded readout and a more modern design. As a kid, they were a little fiddly to use, but I always thought they were interesting. Thank you for the explanation!

[@kreuner11]

Unlocking hidden memories!

[@tommclain3335]

battery tester included! i remember choosing those on the shelf before others without the test strip

[@elvinhaak]

I used them sometimes to check if they still worked in stored (in packages) packs... but thinking too that they were using more in the battery then in actual use.

[@ph33lix]

I remember thinking these were super cool as a kid. But boy would I have to press into the points till my fingernails bent. Now that you've mentioned the thermocromic material, I recall thinking at the time that it looked very similar to the fever thermometer strips that were very common in the 90s, thanks for the confirmation!

[@Tech_Princess]

I was fascinated by these as a kid. As soon as I saw this video, I clicked on it as fast as I could.

[@notharry9350]

These and the Duracell Quantum are all I'd use in my 360 controller. 💀🤣

[@monkeywithocd]

I regularly think back to these, I thought they were so cool growing up.

[@coldravioli7839]

Seems like this idea solves a problem people didn't really have. I remember having them as a kid and struggling to ever get the tester to even work, even with new batteries.

[@ExtraSaltyWAGMI]

I agree that most people put fresh batteries in something until it dies, but growing up in the 90s with every toy and handheld gaming device running on batteries, and in a household where my father worked in audio/visual production, we had half used batteries EVERYWHERE, and the built in tester came in clutch many times for my gameboys!

[@braixeninfection6312]

I remember some of these around the late 2000's. Had some when out hunting with my dad. And yes the kinda sucked to use. Especially since it would be colder out that time of year so they didn't work well anyways. I forgot these even existed because it's been so long since I've seen them!

[@gregwochlik9233]

Ohh, yes! I do remember these! I was a teenager back in South Africa, and the GameBoy that my parents bought in 1991 has survirved to today. I bought some rechargable AA batteries, and played it last about 1 year ago.

[@pattyg1902]

Oh my God I love the Duracell power check those things were so nice

[@T4lyX]

I honestly forgot all about these, great nostalgia trip

[@gogetters6639]

These need to come back.

[@agostinodibella9939]

Cool video! I always liked these testers and figured the extra cost made them go away.

[@verde4337]

These were actually pretty useful for me during my child days. Here in Brazil, summers get pretty hot, hot enough that the heat is enough to make some batteries leak. Therefore we would do everything that we could to keep batteries out of our gizmos, because a battery leak inside it could kill it for good, I lost way too many toys to that. Honestly, I remember dreaming about becoming an adult and replacing every battery in the house with those rechargeable versions that only the rich kids in the block had just to never have to worry about dead batteries in my drawer. All of that live battery handling made us note that some gizmos needed better batteries than others, the new batteries were allocated to the toys, since they were usually more power intensive, while the older ones get downgraded to the remote, which barelly used any. Also the AAA batteries seemed to leak less often than the AA, I only have anedoctal evidence of this, but this might be the reason some devices use AA over AAA

[@Apreche]

It didn't make sense to put battery testers on single-use batteries, but it sure makes a lot of sense to put them on rechargeable batteries. Yet, those don't have them.

[@watchingworm]

I never got these working as a kid 😄 This taught me how they were supposed to work!

[@LEGnewTube]

I remember these. The idea never lasted long and made me super sad :( Awesome to see a video on it 👀

[@williamrusso3130]

The Energizer versions had such a cool look. Very late-90's kind of design.

[@TedLedbetter]

"Like an amoeba" 🦠😂

[@pilottruck1288]

I remember the self test batteries I used being black and green Energizers. They looked so cool!

[@Squonk06]

I remember the Energizer version. It was simpler, though it worked much the same. There was a little window that lit up in green with the word "GOOD" written in black. The dimmer the window, the less life the battery had remaining. There was a border around the window that was the same shade of green so you had something to compare to. I also remember discovering pretty early on that these tests must rely on heat because, if you kept the batteries in a hot room, the "GOOD" windows would all be lit up green without even touching the batteries.

[@bmused55]

I could swear I saw some of these tester batteries in my local supermarket here in the UK recently, I'm gonna need to check!

[@ManWithBeard1990]

Honestly it didn't seem all that long ago that you could still buy these. Perhaps it's because I'm not in the USA. In case you weren't aware, the batteries that had the negative terminal be the battery's body were usually rechargeable ones. I used to have a couple of devices that could recharge their own AA batteries when connected to a wall wart, but only through a third contact on the side of the battery. The manual actually told you to scratch away some of the battery's wrapper to make that work.

[@Sgt_SealCluber]

Only time I used partially used batteries was when I was taken them from one remote (not currently in use) to put in another. It was neat at the time so I did buy a pack or two back in the day.