Introduction: Micro USB Lithium Charger for Cilindrical Lithium Baterry

By Personal blog - in Romanian
About: I like making things, trying to utilize my hands and my brain. There is no limit!

I got a green laser from ebay, pretty cheap and it included one piece of 18650 Lithium battery, wall charger for the battery, caring box for the laser etc. This raised a question mark given the price and the number of objects I received.

In one day I wanted to charge my 18650 battery and after a while, I heard something popping, a sound from the wall charger. The magic smoke came out and the charger was not good anymore. I assumed that some sort of capacitor was blown given the smell and the smoke :)

I removed the screws and I found a blown capacitor. My initial thought was to scrap the charger. After a good sleep, I came back to better feelings: I can use the plastic housing of the charger to put inside a nice micro USB lithium charger PCBA.

More details about this micro USB charger you can find from Julian's video: New TP4056 Lithium Cell Charger Module with Battery Protection (this is from ebay - I picked one randomly: Micro USB 1A Lithium Battery Charger Module)

This is pretty straight forward project, follow the not-so-detailed steps.

Benefits:

-you re-purposed an object instead of creating more garbage

-this charger can accommodate various lithium size batteries

-you can charge lithium batteries wherever you have a micro USB connection (car, home, outdoors)

Step 1: Open the Charger

Use a screw driver to open the charger (on mine were 5 Philips screws)

Step 2: Remove the Electronics of the Charger

Remove the electronic board (PCBA) of the charger, desolder the battery contacts from the electronic board and dispose the electronics board on a recycling bin for electronics

Step 3: Make a Rectangular Hole

Check where the micro USB charger PCB will sit inside the plastic housing and make a rectangular hole to match the micro USB connector of the PCB.

I used a red hot screw driver tip to drill that hole and a cutter to remove any burrs. You can do the same for the LEDs, it is not mandatory (you can see the LEDs through the plastic case).

Step 4: Solder Wires

Solder the wires to the micro USB charger and to the metal contacts for the battery. Pay attention to the polarity ("+" and "-").

Connect a micro USB cable to check that the charger is working.

Step 5: Secure Wires and Parts Inside

Now you have a plastic housing, secure the wires and the micro USB lithium charger inside with hot melt / hot glue.

Make sure that the spring is moving free inside.

Step 6: Enjoy Your Charger :)

Put the charger back, fasten the screws and use your new charger! (the blueish spot on the case is created by the LED from the charger)