By combining a lithium-ion rechargeable battery with an inexpensive charge/discharge board, a compact flashlight was created.
The structure is very simple. It consists of a lithium-ion battery, a charge/discharge module, a step-up DCDC converter, and LEDs.
Lithium-ion batteries are delicate to charge, but by using a dedicated charge/discharge module, they can be charged and discharged safely.
Also, by using a boost-type DCDC converter, a constant current can be applied to the LED, making the light always the same brightness.
This is how I assembled it.
The light shines properly.
Making the case
Design the case in Blender.
Print it with a 3D printer. It consists of two parts, the bottom and the lid, and it took about an hour to print each part.
For the 3D printer, I used the I3 Mega from Anycubic. I'm glad I bought it because it's inexpensive and performs well.
I've taped it in place until I get some glue on it.
It lights up when I turn it on.
It can be charged via USB. The red LED glows while charging.
When charging is complete, the LED turns blue.
All you have to do is wire it up, so it's pretty easy to make.