Introduction: Protable Power Bank

Picture of Protable Power Bank

this is an easy project to make an 5v portable power bank for just 2$!

Step 1: Parts

Picture of Parts

The parts you will need for this project is:

* 3x AAA batteries

* 3x AAA battery holder

* 5v step-up

* SPST switch

* Enclosure

* Hot glue

Step 2: Cut the Wires

Picture of Cut the Wires

Cut the wires from the battery holder to the size you want them to be.

Step 3: The Switch

Picture of The Switch

My switch was a little bitt to big so i had to bend the two mounting plates.

Step 4: Soldering

Picture of Soldering

Solder the ground wire to the 5v step-up module and solder the switch to the positive wire, take an red wire that you cut off from the battery holder and solder it to the other pin on the switch and solder the other and of the wire to the positive connection on the 5v step-up module. When you are done whit the soldering remember to test it.

Step 5: Gluing

Picture of Gluing

Glue the module to the battery holder whit hot glue or superglue, I used superglue first but the module fell off the battery holder when i moved it later so I used hot glue instead. NOTE: never ever glue an switch whit superglue! The glue always finds an way to get inside the switch :P

Step 6: Enclosure

Picture of Enclosure

Make an nice enclosure for your project! I really want an 3D printer but I don't have one so i made my enclosure out of some hard paper I had.


If you liked my project than check out my cannel for more cool projects and if you have made one of my projects or have any questions please post it in the comments. :)


Grisling (author)2015-01-15

I've tried this as well, unfortunately 3xAAA batteries does not charge a smartphone to 100% only 50-60%

Yonatan24 (author)Grisling2015-11-11

That probably happens because the batteries die, and can't give enough amps

Grisling (author)Yonatan242015-11-11

Yes of course...what else would it be??

Tech Works made it! (author)Grisling2016-02-02

5V step-up device are giving 1Ah continuously and your AA give 400–900 mAh which means if 3xAA gives 1200-2700 mAh. then what is the solution.

Just add 3 more AA in parallel. Here you put those three in series now take another 3 in series as the first one and join both +ve and -ve. like this img.

what will happen by doing this both the sets of 3 are giving 4.5V and 1200-2700 mAh after that connection you will get 4.5V and 2400-5400 mAh

ironsmiter (author)Grisling2015-01-15

Depends on the phone. In your case, look for a 2x2 battery holder or even a flat 6. Replace the 5 volt boost circuit with a 5 volt buck circuit.

Not only do the extra batteries add amp hours, but also reduce the load drawn from each cell, making them last longer.

Example: a single aa battery will charge your phone further at a 500mAh draw than the same battery would at 1Ah. Depending on the battery, it can be a LARGE difference. Going from 3aa to 6aa battery pack effectively halves the discharge rate for each battery.
There is bunch of magic battery formulas, but the nitty gritty is, for every battery you add you get a 'free' 15% or so, given the same discharge rate. E.g. going from 2aa to 3aa doesn't add 50% capacity, but rather 65% effective charge capcity. The magic formulas also say that this is exponential, not linear.
(For an indepth explanation of the magic numbers give a read)
dasimpson1981 (author)ironsmiter2015-01-24

and just to add to use the buck circuit the 6 batterys would have to be in series this will not add more amp hours only up the voltage

ibenkos (author)Grisling2015-01-15

Just make two ;) or just do what ironsmiter recommended :)

Tech Works (author)2016-02-02

The 5V step-up which you used are helpful to converting 3.5V to 5V that's whay you used 3xAA Battery but ultimately you are giving 4.5V. Are you not faceing any problem with your step-up device.

1nstructable (author)2015-11-10

Hi guys. Could you help me please with this project? My fully charged 2x18650 butteries doesn't charge iPhone but smart band they does. What the problem?

ibenkos (author)1nstructable2015-11-10

It might be because your 3v to 5v step up doesent produce enough ampere to charge your phone.

tobywinks (author)2015-01-25

Pretty neat! Check out my diy for a wiring time saver. I bet it would help you, and feel free to vote?

dasimpson1981 (author)2015-01-24

the closer to 5 volt you make the battery pack the more efficient the boost converter becomes so maybe 4 batterys rather then the 3 if you start to use over 5 volt then a ubec would be best they are alot more effecent as they stepping down not up

graydog111 (author)2015-01-14

Nice project, but you should use Lithium rechargeable batteries and use an old power cord to recharge them. BTW, Walmart has those for $9.99, but you would not have had the fun of making yours. :-)

domints (author)graydog1112015-01-16

You should NOT be using "old power cord" to recharge Lithium rechargeables, because they might explode.
I don't know why people try to use simple things to charge dangerous and very complex ones. You could charge Lead acid batteries, even Ni-MH / Ni-Cd batteries with simle power source and one resistor, but never try to charge Li-ions and Li-polys with such simple charger, because it might work once or twice, and third time it will explode, when you leave it alone. And trust me, Li-* explosion is quite like not a fun, if not fire, there's lots of awful smoke that is hard to get out of the room, and still furniture smells bad after that.


ibenkos (author)domints2015-01-16

I have an 3,7v li-po battery on something i made and i connected the battery to an female power jack that I was going to have the input of 5v, is that going to explode? if it is wrong what do i have to do? thanks

domints (author)ibenkos2015-01-18

Yup, you have to have specialized charger circuit to not to overcharge your Li-po. Li-po's and Li-ions can't be overcharged over 4,2V, because the're going to explode when charged in that way. The simplest but still safe solution is based on LM317 voltage regulator like on that site:
And of course you have to calculate the Rx value according to your cell.
An that site there's more complex description how Li-* should be treated to work properly, so it's good to read it all :)

ibenkos (author)domints2015-01-18

ok thank you :)

ibenkos (author)2015-01-14

Thanks for the tip :)

About This Instructable




Bio: I am always making electronic stuff. I like to do Arduino projects best. more projects coming soon!
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