Li-Ion batteries (18650 cells) are very widely used in all the electronics gadgets that we use today like mobile phones, laptop, powerbanks, etc. These batteries provide good backup and are a reliable source of power, therefore are also very convenient to use in DIY projects. However, charging these batteries is still hassle as the commercial chargers are quite expensive. Also, a good quality charger is essential for Li-Ion batteries, otherwise the battery life will get degraded soon. A balanced charger does the job well but it is available in higher price range.

So, in this instructable i decided to make a Li-Ion battery charger that can simultaneously charge four 18650 cells together. This charger is very simple to make and performs the work of a balanced charger by stopping the power to the individual cells after the battery gets charged completely.

Step 1: 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 info and images.

Step 2: Order Parts

Ebay.com

General Purpose PCB Board - https://rover.ebay.com/rover/1/711-53200-19255-0/1...
TP4056 Module - https://rover.ebay.com/rover/1/711-53200-19255-0/...
Office Paper Clips - https://rover.ebay.com/rover/1/711-53200-19255-0/...
Header Pins - https://rover.ebay.com/rover/1/711-53200-19255-0/1...
PCB Switch - 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/...
Soldering Iron - https://rover.ebay.com/rover/1/711-53200-19255-0/1...

Amazon.com

General Purpose PCB Board - http://amzn.to/2pnnkur
TP4056 Module - http://amzn.to/2qcIACn
Office Paper Clips - http://amzn.to/2q44oQw
Header Pins - http://amzn.to/2zhGE08
PCB Switch - http://amzn.to/2xKqgqr
3.7v Li-Ion Battery - http://amzn.to/2npKA8m
Soldering Iron - http://amzn.to/2r3IX6g

Amazon.in

General Purpose PCB Board - http://amzn.to/2lkylJH
TP4056 Module - https://amzn.to/2R97Mu3
Office Paper Clips - http://amzn.to/2qIBEhb
Header Pins - http://amzn.to/2wQPiRO
PCB Switch - http://amzn.to/2wGrgbJ
3.7v Li-Ion Battery - http://amzn.to/2mMlK5z
Soldering Iron - http://amzn.to/2qC47qG

Step 3: Let's Begin

Take the general purpose PCB board and place the batteries over the board.
Mark the distance between edges of the batteries and their width on the PCB board. (If the PCB board is big, you can easily cut in size accordingly).
Unfold 8 office paper clips and using pliers cut the clips from the edges as can be seen in the image above.
A total of 8 U-clips (depending on the number of batteries to be charged) are to be made.
Insert the U-clips on the PCB board such that the batteries can be inserted between the clips.
The clips will act as the battery holders.
Also, use the remaining portion from the clips to make the side railings.
Solder the clips on the PCB board really well, as shown in the image. Note: Make sure that the clips don't get connected to eachother while soldering.

Step 4: Add the Components

Place a TP4056 charging module on the PCB board as shown in the image above.
Using a marker, mark the holes of the module on the PCB board.
Solder a header pin in each of the marked holes.
Insert the module over the header pins and solder the module carefully.
Use the number of modules equal to the number of batteries to be charged i.e one module per battery.
Solder all the modules on the PCB board as shown in the image.
Take PCB switches and solder a switch between every module on the PCB board.

Note: Make sure to refer to the images in order to avoid any errors.

Step 5: Connect the Components

Refer to the connection layout above and solder all the components together.
Make sure to mark the polarity on the battery holder made of U-clips.
Connect the battery holder terminals to the input terminals of the TP4056 charging module according to the polarity.
Connect the modules together such that they can input power from a single wall charger.
Also, make connections between the switches such that they can be used to independently control the power to the modules.

Step 6: Test the Battery Charger

Insert the batteries in the battery holder over the PCB board.
Connect a mobile phone charger to one of the module and switch ON the supply.
An indicator will glow on the module to indicate charging.
Use the switches to control the power supplied to the batteries.
Turn all the switches OFF if you want to charge only a single battery.
Turn ON the switches with respect to the number of batteries charging at a certain time.
Since each battery has a separate charger, so they will never face the problem of overcharging and under charging (most common problem that damages Li-ion cells)

Note: A TP4056 charging module is capable to provide 1A at 5v. Since, i have made a 4 battery charger, so it is essential to use a 2A mobile charger, such that atleast 500mA are provide to each cell.

So Friends, this here concludes the tutorial, make one yourself at home and use any number of lithium ion cells without worrying about charging them. Stay tuned and SUBSCRIBE to receive regular updates. Also, Don't forget to leave your feedback and suggestions in the comment section below.

If you don't want to use office clips, you can also make magnetic battery clips. Have a look at the instructables here or watch the video below.