The $40 Hidden Inside a 12V Battery

By Paul Michael on 19 August 2007 (Updated 26 April 2011) 99 comments

Hands up who hates buying batteries. (I had both hands up in the air by the way, briefly, but had to put them down to continue writing this article.) Anyway, batteries are the bane of my life. It seems almost every toy we have for our children or gadget for ourselves require batteries. And they need them in all shapes and sizes. The worst offenders are those button-cell batteries. Small and costly...until I saw the coolest video. (See also: 5 Quick Remote Control Hacks to Save You Time and Money)

Kipkay over at Metacafe has done it again, with a life hack and battery hack that will save you roughly $40 on those 1.5V button cell batteries. All you need is a 2-pack of 12V A23 batteries, which retail at less than $2 a pack. I found my set on Amazon for $1.66.

$40 From a 12V Battery

How To Hack A 12 Volt Battery

As the video shows, you simply split them open to reveal EIGHT 1.5V button-cell batteries, each one worth around $5. And as these 12V batteries come in pairs that gives you a grand total of 16 new batteries worth around $80. Not bad for an initial investment of $1.66. Kipkay also goes on to split a 9V battery for use in a battery emergency. You could say these hacks are literally "power to the people." (Sorry, couldn't resist).

9V Emergency Battery Hack

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Guest's picture
Dennis

Whoa, thats pretty sweet! Do you if the batteries last as long as their expensive counterparts?

Guest's picture
Jordan

As far as I can tell they only last about half as long. Of course if you get 8 batteries then it's still quite a deal. You would basically have 4 batteries for 2 buck's.

Guest's picture
Ben

Okay, this is really cool (and I'll remember it next time I need some of those battery types). However, you really need to compare prices a little more consistently! You can get 394's for $0.99 on Amazon too. At 16 per pack, that's still a ~10x savings though if you need that many!

Guest's picture
Guest

I do not know what the little 9.3mm x 3.0mm batteries are, but they are not 394s.

394 batteries are Silver Oxide, not Alkaline chemistry, AND they are 9.5mm x 3.6mm.

Clearly these are something else!

Other than that, this was helpful, I just yanked an old A23 ($1.50) off my shelf (I use them in my RS Infrared Thermometers), and replaced the 3 dead LR44 batteries in my new $2 LED Screwdriver.

With 5 batteries left over.

And the steel casing from the outside of the A23 was great! I used it to take up the empty space generated by using smaller batteries.

Guest's picture
sharp

battery is necessary in our life, we can leave it!

Guest's picture
Guest

I'll call alkaline batteries dry cells if you call car 12V flooded cells. I just didn't want to hear about someone thinking using AA battery paste as cold cream is OK.

Guest's picture
Guest

H2SO4 in your face anyone?

Guest's picture
Guest

h2so4...if it is a car or acid based battery..

Guest's picture
Guest

learn chemistry please

Guest's picture
concerned citizen

first of all IDIOT, car batteries are Wet Cell. all the batteries we use in our electronics are dry cell.

and cracking open a car battery could KILL you! There's far more Amps in a car battery than in these things.

Guest's picture
Guest

You must be a moron! Go ahead and try this, we need to rid the world of morons....in about 2 minutes or less after you short the battery with the metal rod, it will explode. But go ahead.

Guest's picture
Guest

I'm sure this comment was meant to be funny and tongue-in-cheek.

DO NOT ACTUALLY TRY THIS! The battery may explode or cause a fire, melt, or cause serious burns.

Guest's picture
Guest

Um, someone please delete that comment before someone hurts themselves. I know for a fact that the batt will explode if you short it out. The heat generated by the rapid discharge of the batt will weld the piece of metal to it pertinently which puts it in an unending loop of short out batt heat up bar, short out batt heat up bar and will eventually overheat the batt and cause it to explode!

Guest's picture
Guest

:-P

Guest's picture
cam

I'm sure you were trying to be funny, but the reality is if you put a metal bar across two automobile posts you could get killed. Come on dude, you can be funny but honestly, getting someone to kill themselves is pretty awful.

Guest's picture
Guest

Only if you want to ruin the car battery itself. lol

Putting a metal bar across the battery terminals will heat the bar red-hot and if you do it for 10 mins it will not only drain your battery, but probably melt it as well.

and LOL at the claw hammer. Why would anyone do that. You're not only going to have a mess, but a mess of chemicals that are corrosive all over your driveway.

I hope no one took that comment seriously, or they're in for a real disappointment and a real headache.

Guest's picture
Guest

i never heard something so stupid in my life !
car battery are not made whit little 1.5 cell battery
they are made of acid if u crush it u ll and u receibe acid in the eyes or somewhere else don't come blame the site because u are the stupide one

Guest's picture
Guest

i never heard something so stupid in my life !
car battery are not made whit little 1.5 cell battery
they are made of acid if u crush it u ll and u receibe acid in the eyes or somewhere else don't come blame the site because u are the stupide one

Guest's picture
Guest

lol! Those little battery sellers must hate energizer and this video!

Guest's picture
Guest

That video sounds just like an infomercial - I kept waiting for the "and if you call now, we'll throw in..."

Guest's picture
devolute

I can imagine this being pretty damn useful for people with hearing aids etc.

Guest's picture
Guest

Although this is an old post, someone else may stumble across this like I did, so I wanted to correct this point. Hearing aid batteries are a totally different zinc air formulation. The air powered by the interaction of air with zinc when the tab is removed from the battery. Although they look similar, they are a totally different chemistry than a silver oxide battery and can not be substituted.

Guest's picture
Guest

hey man thanks fer clearin that up :D

Guest's picture
Guest

Where would I find the vidio for this. I dont understand how this would work.
thanks

Guest's picture
Guest

The day a hearing aid uses batteries that large is the day we all fail as a technologically advancing world.

Guest's picture
David A. Barak

WHAT DID YOU SAY? : )

Guest's picture

Before I go cutting open batteries, I wonder if this hack only applies to the Energizer brand or with cheaper no-name or from China Batteries?

Paul Michael's picture

about batteries from China. You may end up getting burned by that one. Pun intended.

Guest's picture
Charlie Faddis

When you disassemble a 12 battery you get eight 1.5 volt alkaline button cells with a capacity of 0.028 Amp-hr. each.
I know this because I 've disassembled more than 60,000 of them yielding a half million button cells.
Believe me, It has saved me some serious money!

Guest's picture
Paul

Just curious, why would you disassemble 60,0000 batteries? Were you re-selling?

Paul Michael's picture

That's quite an endorsement. 

Guest's picture
Richard

You know - I think next when I need button batteries that I shall dismember some A23s. Also, as a point totally unrelated to batteries, This video was on the end of video 'suggestions list'. Very nice it is too, whilst being completely scientific of course ;-)

Bravo on batteries though!

Guest's picture

In the Army we have a high demand for the 123A battery. These power some optical devices, a handheld hard drive device and the little flashlights that attach to our rifles (Surefire).

In the event that these batteries have to be purchased "on the economy" rather than through the supply system, you can save a few bucks on each one.

Duracel's number is DL-123A. Kodak's is KL-123A. But don't buy these.

Buy the DL-223 or KL-223. These are usually somewhat less than $20 each, while the 123's run about $13. But when you cut off the plastic wrapper of the 223, there's 2 123's inside!

I've linked this article here.

Guest's picture
Guest

RTO,

I must be missing something, you can buy Surefire CR123A's for a couple bucks each and other brands like Battery Station and Amondotech for even less.

Guest's picture
Michael

Some handy info to know, save some cash.

Guest's picture

Thanks for the info, Guest. You mademe reevaluate the current battery market.

Still, I'm talking from a military standpoint where you have to have batteries, right now, so you walk into Wally-World with the unit MPACT card.

Or anyone else, of course, who maybe can't wait for an order to arrive.

Guest's picture
Guest

I took apart a cheap brand and there were no little ones inside.

Guest's picture
Guest

Do you have the Speech Synthezier or Hunt the Wumpus on your TI994A? How the heck do you use those little batteries to power it? Are you talking about the clock batter?

Guest's picture
Guest

must only be american batteries, i opened energizer battery bought in ireland n just battery acid etc!!

Guest's picture
Thomas C.

all i got to say is **** the battery companies. holding out on us.

Guest's picture

good to know - i'll keep that in mind. last time i needed some of those 1.5V batteries we just ordered them on ebay - for pretty cheap.

Guest's picture
Jes

anyway to get 3V button batteries from anything?

Guest's picture
Guest

The only free source of 3v batteries are junk computers, I have access to a virtually unlimited amount of junk computers and the 3v batteries come in handy, good for car remote door lock jobbers.

Paul Michael's picture

Kipkay was the genius who discovered this lovely hack, but I can ask around and do some digging. Watch this space. 

Guest's picture
Charlie Faddis

It was a rainy day, they were there, so...

Guest's picture
FavHost

Definitely worth knowing. I have a couple of the A23 batteries. I'm going to have to check it out.

Guest's picture
Peter

But the video was really quick. It might have been more helpful to show how to match up batteries with products.
A Radioshack 394 battery is not the most common and while it's a neat trick you would have to be a real expert to know which battery will work with what.

Guest's picture
Guest

This was listed on GAGFILMS.COM

Guest's picture
CHESSNOID

That was pretty amazing.

Guest's picture
Guest

OK guys, this is called a "hoax" ...

Guest's picture
krisk

But

what about the quality of the batteries that are included in the large one?

Guest's picture
krisk

Having a larger chemical cell would be the most profitable and logical design choice for the battery makers
NOT including smaller button cells.

Guest's picture
Manufacturing Engineer

Having a single larger cell is not more cost effective. Especially since the "standard" battery dimensions were developed in exactly this way. All batteries are made up of "cells". IT just so happens that some of those cells are finished products in and of themselves. It's very costly to design a new product, let alone gear up to manufacture it. A company can save a lot of money whenever they combine existing, readily available, components to produce a product- whether those components are something they produce, or something they buy from someone else. They don't have to build a substantial new manufacturing line, and they only have to engineer the "wrapper", so to speak. Also, there are specific performance benefits that can be achieved by putting existing battery cells together in different ways. You might be trying to achieve longer runtime, or higher initial current, etc., etc., etc.

So, don't be too quick to disbelieve, all of you who don't work in product design or manufacturing...

Guest's picture
Suzie

And inside each of those smaller batteries are even smaller ones.... ?

Guest's picture
Mir

something about reading this page, watching those videos, and reading the comments makes me think that people are idiots. Seriously.

Guest's picture
noddy

This is just hillarious
People with just so much time
hey "yeah" you are spot on

hey mate with the car battery how about you do it, film it, and stick it on utube, now that would be entertaining!!

Guest's picture
Guest

Got 40 of those batteries for a total of $8 (including S/H) off of ebay. A little bit easier that way...

Guest's picture
Guest

Energizer batteries are made in the US or Japan, except for A23, ehich clearly says "Made in China for Eveready." The little cells inside are chinese made generics / oem, with nowhere near the lasting capacity of regular Energizer made button cells. You get what you pay for :) .

Guest's picture
Evan

Exellent! Those little micropet things you used to get in happy meals will work again!

Guest's picture
wtf

My guess is that this video is bullsh*t.

voltage sources connected in series are additive. eight 1.5 volt batteries equals 12 volts...which is NOT the same voltage as an AA battery.

Guest's picture
Guest

no kidding. its not a "AA" battery it is a 12 volt a 23 size.

Guest's picture
Guest

if you had read the post, you'd have seen that the battery in the video is NOT a "AA" battery, but a 12 volt battery like the kinds used in some digital cameras.

Congratulations at failing.

Guest's picture

reminds me of russian dolls.

Guest's picture
Guest

hahaha morons

Guest's picture
Guest

I've never tried the 12V battery one, but I know for a fact that SOME 9V batteries can be opened up to yield six 1.5V cells, that are roughly the same size as AAA's. Other 9V batteries have a different size/shape of cell in them.

Also, it should be noted that the 1.5V cells that you get out of a 9V battery don't have the little tit on the end, and therefore might not be able to make contact with whatever device you intend to use it in.

Guest's picture
Guest

had a 9v, needed AAAs, tried it, it works.
if you do like they say and bend the little metal piece over, they fit just fine.
i haven't tried the 12v yet, but i promise you the 9v hack works.
it's amazing! makes me so happy!
i don't know how long they last but whatever, they're cheap.

Guest's picture
Guest

Does the exact type matter, like does it have to be A23, because im contemplating doing it with a AA battery i have that isnt A23.

Guest's picture
Bill M

AA batteries won't work because they are only 1.5 volts, the A23 is 12V.

Guest's picture

Simply Amazing.....I have been paying up to $6 for each hearing aid battery for my grandmother, this is a perfect solution! Thanks for the wonderful post.

Guest's picture
Guest

These battery hack videos are complete hoaxes. I can't believe people still fall for them.

Guest's picture
beautox

The 8 cells you get out of one of these 12V batteries are alkaline and hold much less power than the more expensive silver oxide or lithium button cell batteries.

If you could buy alkaline button cells they would be cheap, but the reason battery manufacturers don't sell them is because they would run out in no time at all.

There's no conspiracy. Just engineering.

Guest's picture
Guest

Silver Oxide lasts longer than Alkaline.

Well made Lithium (properly refined) last much longer than Silver Oxide. Good Lithium cells last about 8x longer than Alkaline

Very few button batteries (by type/size) are made with lithium. That WILL be an improvement, and it will come, RSN.

Alkaline/Silver/Lithium has only a little bit to do with the price. You are paying for the convenience of having a small device/battery. ALL button cell batteries cost much less than a single AA Alkaline battery to produce, and yet you are charged much more per unit, and especially per unit of power than AA Alkaline OR AA Lithium.

Lithium AA and, if you can find them, AAA, are fantastic.

Lithium has 8x the power (Ah), and 8x the shelf life.

BTW - the cell voltages of both Silver Oxide and Lithium cells are a bit higher than Alkaline, about 0.05 to 0.10 volts - measurable, but not harmful to the electronics.

Guest's picture

ummm...this seems unsafe and unwise....good try though

Guest's picture
Guest

holy crap

Guest's picture
Guest

hey does it work kirkland signature battery?

Guest's picture
Guest

http://www.top-battery.com.au/
http://www.ibuynow.com.au/
We specialize in substitute laptop batteries (laptop battery) packs for, camcorders batteries, digital camera batteries, PDA batteries, mobile phones batteries, and power tools battery, etc. as well as battery chargers
Online shopping for laptop batteries, laptop AC/DC adapters, battery chargers, camcorder batteries, digital camera batteries, PDA batteries, power tool batteries, 2-way radio batteries, GPS batteries, MP3 player batteries, iPod batteries, DVD player batteries, game player batteries, ink cartridges, laser toner,universal battery and more.

Guest's picture
shridhan

Shridhan Automation is a Manufactures, Exporters & Suppliers a wide variety of Level switches, Level switches for liquids and Level Transmitters for liquids in India.

Guest's picture
Guest

ALL 12V dry cell batteries are made like this- containing 8 1.5 Volt buttons, including the cheap Chinese batteries.

This is for the 12 VOLT ONLY- it's a shorter battery than the AA or AAA- don't try prying open a 1.5 volt AA or AAA battery.

Guest's picture
guest

Not sure what I laughed at more the Videos or peoples comments waiting to find a bunch of batteries to hack apart. If you do this you will 1. You will discover Battery acid and 2. We will discover you on the darwin awards.

Guest's picture
Guest

Did you even see the comment above you?

Guest's picture
Guest

1. Chances of discovering "battery acid" is pretty slim since most batteries that size are alkaline nowadays. In the production of a battery, or more correctly a "cell", you are usually only able to attain a maximum of 3.7V (lithium ion or lithium polymer). Anything above that, including 12V A23 batteries are true "batteries" consisting of multiple cells. I have never done this, but it is perfectly believable. 2. Maybe it is people who think they know everything about everything that we will discover on the Darwin Awards.

Guest's picture
m65

This was excellent. I remember my dad using Brasso to remove scratches from his plastic eyeglass lenses so I figured it had a good chance of working. But this worked great for me. On the two discs I tried it on, it returned them to their former glory. Very happy.

kamagra acne

Guest's picture
shridhan

Shridhan Automation is a Manufactures, Exporters & Suppliers a wide variety of Level switches, Level switches for liquids and Level Transmitters for liquids in India.

Guest's picture

hope no one took that comment seriously, or they're in for a real disappointment and a real headache.

Guest's picture
Guest

Hello,The $40 hidden inside a 12V battery looks like be a good battery .but it can use a long time as battery?And if it is a few expense?

Guest's picture
Guest

So you publicize it on the Internet where everyone can find it? Thanks, now it's gonna cost $80 to change the batteries in my flashlight.

Guest's picture

And the steel casing from the outside of the A23 was great! I used it to take up the empty space generated by using smaller batteries.

Guest's picture

I'm sure you were trying to be funny, but the reality is if you put a metal bar across two automobile posts you could get killed.

Guest's picture

There is actually a new method of rebuilding rechargeable batteries without solder or heat. The connections are factory installed mechanical weldments that accept universal conducters. For more info go to www.battrx.com

Guest's picture
Punky

This is very good to know! Those little batteries are so expensive.

Guest's picture
Guest

Or you can order 60 Button cell batteries from china for 6 dollars like i did, they work perfectly!

Guest's picture
Guest

Can you get anything from a "C" battery?

Guest's picture
Guest

the a23's are about $6 for 2 where im from... and i never use small button cells. no saving for me.

Guest's picture
redman

Poor and misleading.

1. 394 batteries can be purchased as Silver Oxide or Alkaline. The Silver Oxide version will last about 40% longer. The ones you get out of an A23 will be alkaline.

2. The pricing claims in this article are a crock. They claim that the 394 will cost $5 and that the A23 pack only costs $2, but they are comparing on-line A23 prices to in-store 394 prices! If you buy your 394's online (the way they bought the A23), you can get them for about $1 each. So a $1.66 A23 online will provide you with 8 $1 batteries. You get $8 from one A23, not "40" dollars. When you account for the 40% shorter battery life, you get $5 worth of 394'a for a $1.66 A23. That's about a 3 to 1 savings.

3. But wait, now you have to cut open a case, and you have to change your batteries 3 times as often
I don't know about you, but that's just not worth the savings.

Guest's picture
Jordan

Does anybody know if this works with 6v silver-oxide batteries?