Homemade DIY Power Bank Using 18650 Battery




Introduction: Homemade DIY Power Bank Using 18650 Battery

About: Hi, I am Mechanical Engineering student. But loves electronic mini projects. Also like to do creative things. In free time, I will be making something or will be searching for a new idea.

Hello my dear friend,

Want to make power bank at home? Have old dead laptop battery? And want to make something new?

This is a very simple project. You need not to be very good in electronics. It requires very less components.

You can also do much more modifications in it.

I highly recommend you to view this video, it has every thing explained in details.

(This is my first video and project presented on net :))

Step 1: Gather Some Parts

Main required components

  • 18650 Lithium ion battery
  • 1A TP4056 module with protection circuit
  • 3v to 5v USB DC-DC step up module
  • A box/case

Tools Required

  • Soldering gun and some metal
  • Glue gun (if you have)
  • some wires

Step 2: The Boss of Power Bank - BATTERY

The main & costly part in power bank is Battery.

The price of every power bank is always dependent on 18650 battery.

Why to use 18650 only?
• Small in size
• Can store large power than any other
• can sustain High discharge current
• Light Weight

Where to find 18650?
• Old Laptop battery (good source, free, many batteries,original)
• Online or local store

Dead laptop battery also have some working 18650 batteries.

I highly recommend you to use at least 2 batteries. One battery is also sufficient. But more batteries will give you more mAh & more input charging current


Beware of FAKE batteries.

Use trusted sites, stores, brands

take care to do not short circuit. (high power = more precaution)

&& +ve terminal + -ve terminal + short circuit = loss of money

You can also use old 3.7V mobile battery.

Step 3: Connections / Circuit Diagram

Connect modules as shown in diagram.

Connections are very simple.

You can also use Single pole switch instead of DPDT switch.

If you want to increase mAh then connect more batteries in parallel.

2nd image shows connections that i had made for my power bank.

Circuit diagram is explained in details in video.

Step 4: Assembly

This is what I made.

I had not shown you how to make assembly in details. The reason is that, every person does not find same size box/case as shown. They can use their own innovative ideas for fitting all the items in what they find.

1) So besides that, I found a small box at home for my power bank.

2) I fitted a small plastic spacer to make space for battery with glue gun.

3) Then used battery connectors instead of directly connecting wires to battery.

4) Made slots in box using soldering iron (Old tip).

5) Put both modules in box and fixed using glue gun.

6) Inserted Battery & that's it it is ready to use.

Step 5: Testing and Modifications

I Had tested my power bank and shown in video.
The power bank works well & as expected.
The mobile is of 2500mAh
And it charged at the rate of approx. 1% per minute.
The power bank if is fully charged, then it can charge mobile once fully. Then it need to be charge again.
So i suggested you to use more battery. But if you want to make it small then use 1 battery.

Modifications you can do :-
1. Make inbuilt emergency torch.
2. charge by solar panels.
3. You can also use this as power source for arduino 5V projects.
4. Can also use old mobile battery.


Give your opinion regarding to this project & also any improvement needed for presentation & project.



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    33 Discussions

    Hey Rahul! What if like I want to create 12slots of 18650 battery for power bank. What kind of module should I buy? Is it possible to to increase the mAH?

    Why is the positive terminal from TP4056 is connected to negative of DC-DC booster converter?

    1 reply

    I think that is a mistake. I just finished building this. I hooked the positive thru a single pole switch to the positive input on the boost module.


    Tip 4 months ago

    The cells to build DIY powerbanks in the UK can be sourced quickly and at a very good cost here- www.18650.uk


    Question 4 months ago

    Hi, if i wanted to add a solar panel or dynamo in as an additional method to charge the battery where abouts would I add this? I already have a bridge rectifier with smoothing capacitor circuit that produces the correct output voltage from the dynamo. Many thanks


    Question 4 months ago

    Is there any way to get a bust module the will just sense the load and turn on or or there a way to remove the switch from the circuit?

    Hey Friend where I get 1A TP4056 module with protection and 3v~5v usb dc~dc setup module ? Can I get it from local shop or online ? Please reply me 1st ... I want to make it fast !

    1 more answer

    You can found it online easily. Search 'tp4056 protection'

    If I wanted to add a voltage meter to show the amount of power that the battery had left, where in the circuit would I put that?

    1 reply

    I saw 2 types of step up boost module. Which of this 2 modules works best? The blue one output current is 600mah only, while the red one output current rated at 1A-1.5A.

    1 reply

    most phones draw at least 800ma so get the red one

    I want to make a powerbank the same as the one you made. But consist of 2 18650 li-ion battery with 3.7v 6800mAh each. Is it okay for the TP4056 charging module to charge the 2 18650 in parallel connection?

    Since i want to build 4 packs for my family, so I bought 20 18650 cells from


    however, when i go on with the projects, i just find I have no tools to make them together,anyone have great ideas so that i can put them together with easy steps?

    You wrote "I highly recommend you to use at least 2 batteries" but you connected only one in this project. Do you know if the TP4056 module will be working with 2+ batteries or I should use something different? I am looking to use 6 18650 batteries.

    1 reply

    Yes. They will work. Only thing you need to do is connect them in PARALLEL. That's it. And it would be good to to use upto 4 batteries. More batteries provides more current and more risk. Thanks :)

    Did it work like a normal power bank? I mean does it turn off when you don't use it?

    Thanks for nice video

    How would you guys handle undervoltage protection? this device doesn't have it, it will basically draw power from the batteries untill they are at 0.9 volts, at which point the batteries will be dead and unstable.

    1 reply

    I've found out your circuit actually has the undervoltage protection, but that is because u use an upgraded version of the tp4056 with protection module instead of the cheapest one!