Powerbanks are an essential products for our Energy consuming gadgets..It is very difficult to maintain the battery charge throughout the day while using your phone to even half its potential. So, it is important to keep a backup supply always.

In this Instructable, i decided to use my old Laptop battery and make a mobile powerbank from the salvaged cells. A Laptop battery needs replacement every few years but all the Li-ion cells inside it are never damaged. They can be extracted and used for various other purposes.

Note: This PowerBank is only capable of charging Android devices. To charge an ios device it needs a special value of voltage (D+ = 2.76v & D- = 2.06v for 1A current draw and d+ = 2.0v & D- = 2.0v for 500mA current draw) at the data pins that can be easily made using a voltage divider circuit with few resistors. But since i needed it for android devices, so didn't worry much about providing voltage at data pins.

Step 1: Order Parts

Ebay.com

TP4056 Charging Module - https://rover.ebay.com/rover/1/711-53200-19255-0/...
3.7v to 5v Boost Converter - https://rover.ebay.com/rover/1/711-53200-19255-0/1...
Solder Tabs - https://rover.ebay.com/rover/1/711-53200-19255-0/...
Switch - https://rover.ebay.com/rover/1/711-53200-19255-0/...
Soldering Iron - https://rover.ebay.com/rover/1/711-53200-19255-0/1...
Hot Glue Gun - https://rover.ebay.com/rover/1/711-53200-19255-0/...
3.7v Li-ion Battery - https://rover.ebay.com/rover/1/711-53200-19255-0/...

Amazon.com

TP4056 Charging Module - http://amzn.to/2qcIACn
3.7v to 5v Boost Converter - http://amzn.to/2BxwZDM
Solder Tabs - http://amzn.to/2zFEqvb
Switch - http://amzn.to/2xUtkjS
Soldering Iron - http://amzn.to/2r3IX6g
Hot Glue Gun - https://amzn.to/2Sf7oad
3.7v Li-ion Battery - http://amzn.to/2npKA8m

Amazon.in

3.7v Li-ion Battery - http://amzn.to/2mMlK5z
TP4056 Charging Module - https://amzn.to/2C6Jh8D
3.7v to 5v Boost Converter - http://amzn.to/2zAcKUL
Solder Tabs - http://amzn.to/2BmWV48
Switch - http://amzn.to/2wu3K1P
Soldering Iron - http://amzn.to/2qC47qG
Hot Glue Gun - http://amzn.to/2rjNE9r

From Home & Local Store: Cardboard, Double Sided Tape and Connecting Wires.

Step 2: Watch the Video

A video is a wonderful tool that provides deep insight to the procedure and makes it easy to follow. However, also visit next steps for additional details and images.

Step 3: Prepare Li-Ion Batteries

In case you bought new Li-Ion cells, you can skip this step.

If you are also using an old Laptop battery like me, then you can proceed. The laptop batteries are made up of multiple Li-ion cells connected together in certain combinations. When the battery stops charging or becomes faulty, it has mostly been seen that only few cells get damaged, whereas all other cells work well. We will use those cells to make a powerbank at home.

Carefully open the laptop battery without damaging the cells inside.
Using wire stripper, cut the solder tabs connecting the cells.
Separate each cells and clean them with a damp cloth to remove the adhesive.
Using a multimeter, check the voltage of each individual cells.
Discard the cells with voltage less than 2.5v as they might be damaged and will be difficult to revive.
I got four perfectly working batteries out of six.

Step 4: Connect the Cells

Clean the cell terminals properly and if required, you can also sand them gently using sandpaper.
Place all the cells adjacent to eachother.
Apply some solder over the terminals. Note: Make sure to be quick and prevent cells from getting hot.
Take solder tabs and apply solder to both the edges.
Place the solder tab over the cells and connect it to the cell terminal using soldering iron.
Connect all the cells in parallel using the solder Tabs.
Each cell is 3.7v 2200 mAh, so now we have a 3.7v 8800 mAh battery bank.
Also, connect wires to the battery terminals.

Step 5: Make the Enclosure

Take a sheet of cardboard.
Place the battery over the cardboard and mark the dimensions.
Using the dimensions, make a box to fit the batteries and the electronic circuit.
The design can very with your choice of placement of the components.
Be creative and make your own design.
Mark the space for the components, so they can be placed easily.
Using knife, cut the slots for switch, USB port and Micro USB Port carefully.

Note: Make sure to refer to the images attached above or watch the video.

Step 6: Connect the Components

Using Double sided tape, attach the batteries to the Enclosure Base.
Place the TP4056 charging Module at the designed space and secure it with Double sided tape.
Similarly, place the 5v boost converter in the designed space and secure it with double sided tape.
Secure the switch in the slot using Hot Glue.
Refer to the circuit schematic above and connect the components using Soldering iron.
Before testing the powerbank, it is important to check the output voltage in order to protect your mobile phone from any damage.
Using multimeter, test the output voltage of boost converter and regulate it to 5v using potentiometer knob.
Plug in a USB cable and test the powerbank.
Cut a piece of cardboard piece to cover the box.
Make a slit at the top for the indicator light on the charging module as shown in the image above.
Using Hot glue, seal the box completely.

Step 7: Test Mobile Powerbank

Our Homemade Mobile Powerbank is now ready. Plug in a USB device and see it charging quickly with this 8800 mAh powerbank.

So friends, this here concludes the instructable, stay tuned and Follow to receive regular updates. In case you might have missed, watch the video and see how i made this mobile Powerbank at home.

Make this amazing gadget yourself and contact us or share your experiences on our facebook page, twitter and instagram. You can also SUBSCRIBE to our Youtube Channel GOODTECH - Creativity And Science, where i frequently post new and creative content.

I also made a emergency hand operated mobile charger that uses DC motor as generator. Have a look at the instructable here or watch the video below.