Introduction: DIY 5v Portable USB Power Supply

About: Hi, my name is Antoine and i like to teach pepole. I do a lot of stuff like soldering and coding.

Hi! Today i'm gonna show you how to make a portable 5v USB power supply.This project run on an 9v battery and use a car charger from the dollar store.

You will learn about USB charger and how they work. We will make our own 9v battery clip!

Don't worry if it look a little hard for you, i made a really good step-by-step instruction guide.

Let's start!

Step 1: The Tools

The tools you will need are:

Soldering iron.

Wire stripper.

Helping hands.


2x 9v batterys.

Wire cutter.


Here are some links to find some of the tools:

Soldering iron:

Wire stripper:

Helping hands;


Wire cutter:


Step 2: The Material

I'm gonna use a USB car charger from the dollar store.

2 x little wires (5 cm)

2 x 9v battery

Step 3: Open the Charger

The first thing we will do is to open the charger. What we want is the PCB inside. I'm using a kitchen knife to open it. The spot is show in the photos. Once you have the circuit board, cut the spring and the metal contact from the wires using the wire cutter.

Step 4: Making the Battery Holder and Soldering.

Next we are gonna make the 9v holder, using an other 9v battery! You will ned your battery and the wire cutter for this.


1- Take off the label out.

2- With te wire cutter, start to take of the corner. Check to photos for more details.

3- Using a knife, began to remove the black top.

4- Cut the little flat metal wire.

So you will need to solder some wires to it.

First stripp all the sides on the 2 wires and tin them.

Apply lot of solder to the 2 metal contacts on the batery clip.

Soder on the wires, one wire for one side.

Strip and tin the black and the red wires of the PCB.

Solder the wires from the battery clip to the PCB like show on the photos.

Use black electric tape to insulate the wires.

Step 5: Finish Product and Testing

Now we need to test it. First, plug in the 9v battery in the battery clip, the little LED should light up.

If everything work, its time to check to voltage. Use you multi meter, - to - and + to +. If it display 5v, it is right!

So thats it! Your own portabe 5v power supply. You can even use it to charger your phone or anything else that use USB.

I hope you like.

Please leave an idea for my next project in the comments. Tank you!