Step 1: Materials
The materials needed are:
One 18650 battery
One 18650 Holder
One TP4056 Charging module
I had to cut the side "flaps" to be easyer to insert and remove the battery, pass the black negative wire inside the lateral side of the case, glue it using super glue and trim the wire in the top of the case, stripping the top wire to be able to fit the module
Step 2: Connection
Place and secure the module using double sided tape, solder the negative and positive wires
Step 3: "top Case"
Cut and trim a little piece of clear plastic to had more protection to the module, secure it with double sided tape on the sides and glue the exposed conections on top
Step 4: Lets Test It
I put a small stripe of tape to the case to be easyer to take the battery out.
The blue light turn on when you connect the charger, turn red while is charging and turn on again when is fully charged ;) simple, easy and with protection voltage control.
Tank you for watching