5V Mini Portable Power Supply




About: I am an 18 years old hobbyist who finds a great drive in tinkering with electronic circuits. The reason I love electronics is that it empowers me to solve real-life issues with ease. I also enjoy making gadg...

All of us who have had some history with tinkering and electronics, have faced an issue quite frequently. The problem of powering up 5V projects! Since there are no things such as 5V batteries in the common market and powering up those projects using a 9V battery might be risky. The only solution we had to such issues was to add a 5V regulator in our every project. But that was too expensive and tedious and caused a problem whenever the project we had to make was hectic. So to solve this problem, I present to you this "5V Mini Portable Power Supply". It is based on the usage of a 9V battery (which is easily available to everyone) which makes it good for general use. Since the whole project is made on a 9V battery clip, therefore it is the same size as your generic 9V battery clip. Therefore supplying the project would be the same as if you were powering it through a 9V battery and battery clip. However, in this case the battery will only be supplying 5V due to the embedded circuit within the project.

That's all for the introduction. So without further ado, let's start making it!

Step 1: Gathering Around Some Stuff

This project is based on "jellybean parts"(easily available) therefore you might probably have these parts beforehand. The components required for this project are as follows:

  1. A 9V Battery Clip
  2. Heat Shrink Tube (1.5-2cm)
  3. A 5V Voltage Regulator(LM7805)
  4. A Filtering Capacitor
  5. Some wire.
Since I'm into recycling, I have preferred to salvage the battery clip from another dead battery. For the heat shrink tube, please make sure that it should easily cover the clip along with the regulator.
The filtering capacitor can be any electrolytic capacitor based on the usage. I'll be using my 100uF SMD capacitors for this purpose.

Step 2: Soldering the Voltage Regulator and the Capacitor

To keep the project compact, I have done everything on the clip itself. Therefore the regulator also has to be placed on the clip. It may be done by following the below steps:

  1. Pick up the 9V battery clip and cut the metallic plates which come out of it. Now you should be left with only the 9V battery terminals. Add flux to them and then add solder blobs to them.
  2. In your voltage regulator (LM7805), there should be 3 pins, the middle one(PIN-2) is the GND or the negative pin. Remove that pin. This has been done to prevent shorting of the pins.
  3. After that is done, sand or scratch the top plate of LM7805 using any of your tools. I had used a sandpaper to do so. Keep sanding or scratching it until you are able to see copper's lustre. Here, the reason why we're doing this is because the top plate is also a GND pin.
  4. Now that the copper of the top plate is exposed, solder it to the cathode of the battery clip. Be careful here because the polarity of the battery clip and any 9V battery is opposite. Therefore solder the voltage regulator keeping this in mind.
  5. Solder the left pin or PIN-1 (according to the pin configuration posted above) to the anode of the clip.

The Filtering Capacitor:

Pick up the filtering capacitor and place it along LM7805. After that, solder the anode of the capacitor to PIN-3 and cathode to the GND plate of LM7805.

Step 3: Drawing Out Wires

Now all of the circuitry is done and all that is left is to draw out wires for supplying 5V output from the battery. This may be done by simply soldering the wires directly to the GND plate and PIN-3 of LM7805. PIN-3 will be +5V and GND plate will be GND.

Now that everything has been done, you may test if you're getting 5V output from the drawn out wires using a multi-meter. After you've successfully tested it, proceed to the next step, that is the insulating part.

Step 4: Insulating Everything

For insulating the entire setup, push your heat shrink tube up the clip and after it is placed ideally, heat it to insulate everything. After the shrinking is done, neatly cut the tube covering the terminals for inserting the battery.

In my case, I didn't have any heat shrink tube wider than 1cm therefore I had to switch to using tape as a last resort.

That concludes this step.

Step 5: Congratulations

You have finished making this project and may use it to power anything which requires a regulated 5V power supply. So go ahead and make your projects more compact by using this power supply.

That's all for this instructable! If you have any doubt, feel free to comment. Don't forget to follow me if you liked this instructable.

I'd appreciate it if you support me on Patreon.

Project By:

Utkarsh Verma

Thanks to Ashish Choudhary for lending his camera.



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    7 Discussions


    1 year ago

    What a great idea! I like that it is made on the battery clip so you don't have an extra "box" connected.

    Would be even better if you could make a version using a buck converter. MC34063 is easy to use, common, and cheap!

    2 replies

    Reply 1 year ago

    Thanks for the suggestions. I, currently, have my hands full. Will try them out later on.

    Both will be added on this instructable.


    Reply 1 year ago

    I also think it would be a good idea if you have a protection diode connected backwards across the battery, so if you accidentally try to put the clip on the wrong way it will short circuit the battery instead of destroying the regulator!


    1 year ago

    Could this be used to charge a cell phone with the appropriate connector?

    3 replies

    Reply 1 year ago

    Yes, it can be used for charging phones as phones require 5V and that is what this converter does.