Portable USB Charger (Version 2.0)




The project name says it all. It is a device that will charge things like Ipods, PDAs, other other devices that plugs into a USB to charge.

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Step 1: Supplies

The parts needed for this project are all in the second picture.

You will require:

LM or MC 7805 +5VDC Voltage Regulator
Type-A Female USB Port
100 UF Electrolytic Capacitor 10-50v
0.1-0.5 UF Capacitor  6-50v (any type would do)
150-160 ohm Resistor (optional)
9V Battery clip
2.2V 20mA LED color of your choice (optional)
Unprinted circuit board
ON/OFF Switch (optional)

These parts can be easily purchased at your local electronic store, like Radio Shack. Or you can buy them online at:


USB port:

100 uF Capacitor:

0.1 uF Capacitor:

Step 2: The Circuit Board (Simple Way)

The following picture shows the prepared PCB before putting in the necessary components.

What your looking at is the underside of a PCB with the copper foil facing you.
The gray line represent the location where the cut is to be made. Make sure that the 3 sections are electrically isolated (do not conduct to each other).  If you have a dremel tool, you can score the copper cladding with a cutting wheel.

The black dots are the locations where holes are to be drilled.

Step 3: Attching the Components

Watch the polarity when putting in the components, especially the regulator, or it will get very hot and burn out.

*BEFORE plugging in your USB device to this charger, test the charger's output using a multimeter. Hookup the 9-volt battery and measure voltage output, it should be between 4.8-volts to 5.2 volts.

*If the black light comes on when you plug the iPod into the charger, that means the charger is working correctly, and if the black light doesn't come on after 3 seconds, remove the iPod from the charger immediately, and recheck your charger for shorting or incorrect polarity.

*If you double checked the output and still no luck, try attaching a resistor bank described in the comments below to the data lines.

Step 4: The Printed Circuit Board

The first picture is the circuit that is to be etched onto the PCB, the second picture shows where everything should go.

*Your looking at the side with the copper foil, so watch the polarity when putting in the components

Step 5: Printed Circuit With LED

This design incorporates a LED which will be lit when the device is turned on.

Step 6: Adding the Switch

Add a switch to this circuit is very simple, it'll save a lot of battery when you turn it off than just leaving it on idle. You can attach the switch anywhere BEFORE the capacitor (if you did not use a capacitor, then before the 7805).

Step 7: Done!

Now that you've finished building your own USB charger, all you have left to do is to put it in a nice box and show it off to your friends!

1 Person Made This Project!


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523 Discussions


2 years ago

what r the ways 2 boost d charging rate???


2 years ago

why do v use capacitors??

1 Amp is not good enough for a phone charger...i have very cheap china car charger rated at 5 volt and 2 Amp the charging is fast and quick better than original samsung charger. And of course the device is dirt cheap as always...I am starting to believe what China these days


6 years ago on Introduction

Hello sir,
I have a doubt regarding PCB etching provided.
The 7805 has the 2nd terminal as ground and 3rd terminal as output but the design given seems to have 2nd terminal connected to output and 3rdterminal to ground(As it seems to be connected to -ve terminal of battery). Can you please provide an explaination where I could've gone wrong in the interpretation?

1 reply

4 years ago on Introduction

this circuit is able to imput charge in the battery for reacharger?


4 years ago on Introduction

https://www.youtube.com/watch?v=B6hxCUuh1Q4 what and Make by Own Best of Luck


4 years ago on Introduction

i'm willing to build a buck-boost converter (5v output) for my thermoelectric generator. For now i'm still cant design it. So the alternative way for me is to build a boost converter and make sure input of those converter doesnt exceed 5v. My question, can i use this circuit as the boost converter?


4 years ago

Can you use a rechargeable 9V battery? As I plan to have the battery hooked up to a solar panel as part of my AS level DT project


6 years ago on Introduction

Hello SIR ,
Can u tell me what is highest voltage that can i give as an input to this charger and who many cell phones can it charge is 9 V is supplied as input????

4 replies

Reply 4 years ago on Introduction

Input voltage of 7805 regulator is 5V-18V and output voltage is 5V (4.8V-5.2V). regulator use to maintain the output voltage so this circuit can be use as a phone charger for motorcycle. am i right sir?


Reply 4 years ago on Introduction

Input voltage of 7805 regulator is 5V-18V and output voltage is 5V (4.8V-5.2V). regulator use to maintain the output voltage so this circuit can be use as a phone charger for motorcycle. am i right sir?


4 years ago on Introduction

hey! how can i do same with this kind of 6 volt 4.5Ah battery


6 years ago on Step 7

USB Female hubs have 4 prongs as you've probably noticed. the right and left ones are ground and power respectively. The middle ones are the Data + and the Data -. for 99% of the phones out there you don't need to attach anything to the data ports. Apple products however have a strict security feature that will not allow one to use home made chargers.. you can hack this by "tricking" your apple product into thinking that it is actually plugged into a laptop. This can be done by splitting the power from the Voltage Regulator into two wires and attaching them to BOTH of the data ports WITH 100 ohms resistors (on each port). It's IMPORTANT that you use the 100 Volt resistors because you can blow your iphone/ipad 's usb port otherwise and never be able to charge it again. Good luck with your chargers!

1 reply

5 years ago

I am getting a proper 5V output
But i am not able to charge my iphone 5s
Please help me out


5 years ago

As an Electrical engineer, I concur with @wildsevohn that the design, though able to produce a 5V output and probably be able to release some good amount of current juice(few hundreds of mA), it's definitely NOT one of the best( in terms of safety & efficiency) method to charge your phone.
Probably we need to look into designs of higher efficiency, for eg by Ladyada and others on Google. Since a voltage regulator, in theory (and in practice) is NEVER as efficient as a switched mode power supply (SMPS) , this design definitely needs a reboot! Do take a look a Ladyada's design. Search for her name in Instructables.

Anyway, thanks for the author for putting up this tutorial! We all learn from one another :)