12 Volt Battery Hack! You'll Be Surprised...




About: Tinkerer, hackster and prankster. Hit me up on Facebook: https://www.facebook.com/kipkayvideos/ Thanks for checking out my Instructables!
Save $40 with this easy to do hack that takes less than a minute! Pay attention to the battery type as that is important.

This can also be done with a 9 volt battery!

Step 1: It's So EZ!!

I picked up a couple of A23 Energizer Batteries at Wal-Mart for $1.88. What a deal!! If you look carefully at an A23, there is a split in the label/housing. I used a small screwdriver and peeled away the housing revealing a piece of paper.

Step 2: What's Inside??

Peeling back the paper, I found 8 (1.5 volt) button cell batteries!! These are perfectly good button cells that will work in any 1.5 volt device they fit in!

Step 3: Save $40!!

I matched the battery at Radio Shack and 1 of those button cells cost $4.99! Do the math! This easy hack gets you 8 button cells for about 1/2 of what one costs! Have Fun, Be Sfae! Hope you enjoyed this EZ, money saving hack!

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    370 Discussions


    9 years ago on Introduction

    I just attempted this with a Duracell MN 21/23 12v battery and this trick works for it as well. As for the button cells themselves, they have "LR932" written at the top of them. Thanks for the cool tip Kipkay! :)

    1 reply

    Reply 9 years ago on Introduction

    This posting has won today's "I Made It" Challenge. For winning you will receive a 3 month pro membership!

    Thanks for using instructables!



    2 years ago

    dont do there mite be acide in it


    Reply 2 years ago

    Awesome stuff ! Thanks a lot..


    4 years ago on Introduction

    Here you get a 12V Nonspecialbrand-Battery for about 50 Cent, so you get 8 ButtonCells for that price.

    LR932 (ca. 9,3 x 3,2mm) can easily replace LR1130 (11,6 x 3,1mm)!

    I just use them to feed my LED powered Pocket- 30x Magnifier.

    A23 are sometimes also named "8LR932" sic!

    Cool Stuff!


    1 reply

    Reply 4 years ago on Introduction

    Just took a Pic!

    For fixing the smaller cells I just placed some wrapped paper around them, but actually it´s not necessary here, the loupe just makes less noise being shaken now.


    4 years ago on Introduction

    just a heads up, the batteries he is comparing at $4.99 are silver oxide, a different and superior (and more expensive) chemistry to the alkalines in the 23a just so we are comparing apples to apples.


    4 years ago on Introduction

    You can reverse the above and repair an A23 battery!
    A23 batteries are still available, though they began as photoflash
    batteries for cameras nobody uses anymore. The reason A23s are still in
    use is that they are just right for simple remotes that aren't really
    used much, such as your garage door opener remote (2 1-second presses
    per day? 4, maybe?). The A23's 12 volts allows easy design of a door
    opener which puts out an infrequent but powerful burst of
    radio-frequency signal that is strong enough to work reliably from a
    fair distance under poor conditions.

    Now back to the battery.
    Of course your door opener will fail at the worst time. It has only
    been two or three years since you replaced the battery, and that one was
    the second one in your A23 pack. Amazon will get you another pack, but
    it will take a week. Maybe you can find the battery locally, but don't
    bet on it these days.

    But you can repair it !! Think
    about it. Why should an alkaline battery fail in two or three years of
    minimal use? The rating of the A23, 40 mAH (milliampere hours), is
    144000 milliampere seconds. If each press is 1 second long and draws 10
    milliamperes from the battery, you should get 14400 presses from an
    A23. At four presses per day, that's 3600 days of opening your garage,
    or about ten years from that little battery! And most of us will
    agree that an unused alkaline battery will still have most of its life
    after ten years on the shelf, so it shouldn't be dead of old age in only
    two or three years. So why is my garage door opener battery dead in
    two years?

    I took the battery apart to find out why my
    digital voltmeter read the battery as having only 7 volts output. Each
    cell measured over 1.54 volts. They were like new. All right, then,
    why doesn't the battery give me 1.54 x 8 = 12.32 volts? It's that black stuff on the LR932 cell terminals from the cheap plating
    that the manufacturer used. There are 8 LR932 cells, so there are 16
    metal surfaces that can corrode, and corrode they had. The cells had
    not leaked; it is the kind of corrosion that happens with low-voltage contacts made by inappropriate metals,
    which is what the Chinese who made the cells used. Those of us who
    have designed or repaired electronics for a living have seen the same
    problem of contact corrosion resulting from the wrong plating in the
    wrong place many times.

    So now let's fix the battery and
    get that garage door to open again. Take the battery apart, being
    careful to save the additional metal terminal parts and washers at each
    end. There's a spring under the + contact (red), so be ready for that
    and protect against it flying away. If you have a voltmeter, check each
    cell, making contact on the side of the cell for + and on the small end
    for -. You will not have to press very hard. I think you will see
    what I saw--the "dead" battery just has corroded contacts on the cells
    that are inside; otherwise the cells are fine.

    Get some sandpaper,
    100 to 200 grit (medium fine), and rub each end of each cell until the
    black stuff is gone. Don't overdo it--just make most of the black stuff
    go away. After that, wash each cell using a little rubbing alcohol or
    distilled water and a Kleenex or Q-tip to get the sandpaper dust off the

    Get a two-inch strip of blue painters' masking tape,
    the kind that isn't super sticky but sticky enough, fold the ends about
    a quarter inch, and attach it to your work surface so it is flat with
    the sticky side up. Assemble the battery horizontally with the cells
    touching in series just as it was when you took it apart. Now take
    another piece of the blue masking tape and gently attach it to the sides
    of the cells that the first piece of tape does not touch. Push the
    cells together and smooth the second piece of tape around the battery.
    The goal is to neatly cover the battery with one layer of tape.

    When you are done
    you'll have a blue cylinder of tape around the battery. Don't close
    the ends; instead, open them with a pencil or small tool. Collect the
    small terminal parts you saved and put them back in place by pushing
    them into the cylinder and tweaking their position. (Hint: The end of
    each terminal that sticks out has a washer on it. And don't skip the
    spring.) Now push on each end where the terminal is, and make sure it
    is square, and lastly push on both ends at once. Now close the ends of
    the tape cylinder by folding over the tape. Trim the tape with an Xacto
    or other sharp knife so that the tape does not build any higher than
    the terminals, and clear away the tape where the terminals are. Test
    the battery for 12 volts if you have a meter, and then go open the
    garage door again.

    How long will this last? Probably at least long enough to get another battery,
    but if your door opener remote has strong spring pressure on its ends,
    it could be two or three years till the cells have to be cleaned again.
    If the cells had been plated properly for a few more cents, the A23 battery would never have had to be taken apart.

    1 reply

    Reply 4 years ago on Introduction

    I use an A23 battery in a wireless bike computer. It started skipping, and I saw that it was down to 9 volts from 12. I could only find and buy MN21/23. The battery is the same shape, 2mm shorter, but it does not work. It goes into a housing with a spring, so the 2 mm length seem not to matter. It tests as having 12+ volts. So why does not work? Your help would be appreciated.


    Reply 6 years ago on Introduction

    Replying to old posts, FTW.
    A23 is small and 12V for certain cameras.
    AA is for general purposes and are 1V5 (1.5V)


    6 years ago on Introduction

    Can u give tips on more little batteries in batteries?
    I would like to know.


    7 years ago on Step 2

    Okay, so now im confused. before i open a battery and possibly scar myself with battery acid, Is this real?


    10 years ago on Step 3

    LISTEN UP THIS ONLY WORCKS WHITH ENERGISER. I opened up a 1.5v battery up and got 8 button battery's. Than I opened up a 9v battery and found 6 AAA batters inside. Last I opened up a 6v heavy duty battery up and found 32 AA or AAA I forgot !!!!!!!!

    3 replies

    Reply 9 years ago on Step 3

    wrong 1.5 battery is actually a cell not battery 9 volt has 6 AAAA cells in it...(1.5v each) 6 volt has 4 large cells...(1.5v each) if a 6 volt had 32 AA or AAA batteries it would be 48 volts

    minimoto right
    cjmproductoin partial credit. :)

    32 AA or AAA *in series* would be 48 V. (32 * 1.5 = 48). However, 8 *parallel* banks of 4 AA or AAA in series would be 6 V at 8 times the current (amps).
    (4 * 1.5) = 6, 8 times. Series connection adds the voltages; parallel connection adds the currents.

    *                    * is 6 v, i amps

    *    *   *     *   *
    *    *   *     *   *
    *    *   *     *   *
    *    *   *     *   *
    *    *   *     *   *
    *    *   *     *   *
    *    *   *     *   *
    *                    * is 6 v, 8i amps