DIY 5v Portable USB Power Supply




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!

Be the First to Share


    • Paint Challenge

      Paint Challenge
    • Unusual Uses Contest

      Unusual Uses Contest
    • Laser Challenge

      Laser Challenge



    5 years ago

    Bought one from Targus ages ago. kind of a disappointment. 9V cells are expensive an at most have 500mAh of juice on them. Typical phone has 1000mAh capacity battery, and the conversion is by no means efficient, so at most you get to charge about 1/4 battery on your phone.


    Reply 5 years ago

    Hello! You mean you had buy an USB car charger and that you tried my project? Higher quality 9v cells can be more power full, so it can charger a bit more that a cheap one. But, its sur it can't charge up to 100% the battery on your phone. It can't charger a big tablette, eaven an Ipad mini can't be charge. My project is good to supply 5v with USB. Tank you!


    5 years ago

    Just a thought--on eBay ten 9v battery connectors cost $1.25 including shipping. This might be a safer and easier way to get the connector instead of taking apart a battery.


    Reply 5 years ago

    Hi ! Yes i know we can buy a connector on ebay, but it was just to show pepole if they can't buy one online. Hope you understand! Tank you.

    DIY Hacks and How Tos

    These kinds of power supplies are great for charging portable electronics in a pinch.