Double Voltage of Your One AA Battery Device




A very simple method to get double output voltage within the space of a single AA battery. Useful for strengthen your single battery powered device, eg. flash light, nose hair trimer and etc.

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Step 1: Reason

Sometimes you are not satisfy with the POWER of your single battery powered device, such as your dim tiny flash light, tooth polisher or the MOST common used nose hair trimmer.

For me, I have changed a lot of them but they are all slow even when I use a NEW battery.

Each time I used them I sweared to put TWO batteries inside it someday.

Step 2: Got the Spirit of the ENELOOP Battery

Got the spirit of the ENELOOP battery today! Why don't we use TWO SMALL batteries with physical adapter?

Step 3: What You Need in ALL.

This is what you need in ALL:

one AA battery as a ruler;
one 9V battery for giving birth of SMALL batteries :)
pliers or scissors

It will take 5 to 10 minutes to finish it.

Step 4: Giving Birth to Small Batteries

Now let's giving birth to small batteries! Carefully open the case of the 9V battery.

Be sure not to choose the cheap band, some cheap band only have square babies.

DURACELL works fine here in US, you may make a try in other country.

Step 5: Cut Babies Into Single

Here we got 6 baby batteries and each of them is 1.5V and powerful ENOUGH.

Step 6: Cut the End As What We Need

Be careful, we are going to cut the linkage metal into what we need.
Flat end short and the other end long;
Please do not just cut it down in equal by scissors.

Step 7: Hard Core

Here comes the hard core of our DOUBLE battery. We are to put them together and make them as long as the AA battery.

Step 8: Cut a Bit of Skin of One

Mark the point and cut a bit of skin of one.

Step 9: Tape Them Together

Tape them together and make sure one battery's end is firmly contact with the other's naked body, that's why we cut the skin before.

Firmly contact please.

Step 10: You've Done

Tape them with more tape and keep IT at the length of a AA size battery, you've done.

Step 11: Don't Fall for Its Shape

Man, don't fall for its shape! The positive end is the FLAT one!

Step 12: Get Ready to USE It

ok, get ready to USE it.
Same length, almost same width, flat as the positive.

Step 13: LENGTH

You can even fine tunning the length by slightly bentting the ends.

Step 14: Yes It Works!

Yes, it works here.

Step 15: Sounds Powerful

sounds powerful and never had this kind of trimming experiance before

Step 16: For Really Tighten Application

for some really tighten applications like this kind of Maglite flashlight, please shape the baby batteries a little flat BEFORE putting two together.

Step 17: Keep in Mind

Please keep in mind, other BABY batteries have the FLAT end as the positive.
Good luck on your next hobby DIY!

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    19 Discussions

    He's doubling the voltage out put to the motor. 2X the rpm at the sacrifice of some run time and a little lower max amperage. I may try this as my trimmers lack a little speed Those "babies" are AAAA batteries. I have a pen light that takes them. this is where I source my batteries for it as AAAA's are about as expensive as AAA's if not more.

    Good point! It's been a while since I looked at this, but I was probably looking for voltage doubler circuits and got annoyed when I realized what this was.

    Thank you for the correction!


    2 years ago

    y not put the batterys in parralel so u still have the 1.5 volts and u have longer living batterys in the end and put it in an old battery after taking everything out of it.


    3 years ago

    How to double the voltage of your battery! Use different batteries!


    5 years ago on Introduction

    An idea instead of destroying a 9v battery that you can add in series all day long are watch batteries? I found that a large enough plastic straw and right size batteries to fit snug in it and now you are making not taking apart. Play around with different sizes. Just remember that series adds voltage 1.5 += 3.0 and parallel stays same voltage but last longer current.


    6 years ago on Step 16

    You could possibly break the seals (or the battery casing itself) on the batteries doing this, causing leakage and ruining your devices.


    9 years ago on Introduction

    doesn't everyone realize you could just get some 14500 batteries? up to 4.2V in a rechargeable AA size thing. No hacking needed.


    10 years ago on Step 4

    in the uk the batteries inside a duracell 9v are red,even though tey look the same on the outside.


    y not put the batterys in parralel so u still have the 1.5 volts and u have longer living batterys in the end and put it in an old battery after taking everything out of it.

    3 replies

    Reply 10 years ago on Introduction

    Because he wants it to be more powerful not longer lasting, so he puts 2 1.5v batts to double the power (3v). Get it?


    Reply 10 years ago on Introduction

    yes but if u blow up the torch not my proplom. and if u use it in parralel u can get longer lasting and brighter for longer... am i not correct..????


    Reply 10 years ago on Introduction

    Yes you could put the batteries in parallel but thats not the point of this ible, he wants more power not longer lasting... And you could blow out the bulb but its not going to "Blow up"... i thought you were talking about the trimmer :P btw its problem not proplom...


    10 years ago on Introduction

    Very nice instructable. Not that I'm not a fan of hacking things up, but I did want to point out another alternative if anyone's interested in going the 'double voltage' route. Lots of battery websites like offer rechargeable Ni-MH batteries at 1/3 and 2/3 the size of a standard AA. A combination of the two would produce one AA-size battery rated at ~2.4v. This can come in handy for those tight spaces where you'd want to increase the voltage! Again, great instructable!

    1 reply

    10 years ago on Introduction

    Awesome project - As for 'the best trimming experience'...just wait till that little sucker grabs your sinuses and rips them out your head :D Good job!