Nowadays, Lithium batteries are used extensively in portable devices, such as cellphones, laptop computers, electronic gadgets, … etc. There is a standard industry-defined procedure (cycle) for charging the lithium-ion/lithium-polymer batteries, otherwise, the lifetime of the batteries is reduced significantly or even they might explode and catch fire. As a basic rule of thumb, a lithium battery should be charged at the rate of 0.5C to 1C. In this article/video, I have introduced a universal double lithium battery charger that the charging current (C rate) can be adjusted simply by changing a resistor value. You just need a 5V power source (such as a mobile charger) and a USB Type-C cable.
To design the schematic and PC, I used Altium Designer 22 and the SamacSys component libraries (Altium Plugin). To get high-quality PCB boards, I sent the Gerbers to PCBWay and purchased original components using componentsearchengine.com. To examine the charging current/voltage, I used the Siglent SDM3045X multimeter. Isn’t cool?!, So let’s get started!
YouTube: https://www.youtube.com/watch?v=aicQEB17ZCY
References
Ref: Double Lithium-Ion/Lithium-Polymer USB Type-C Charger - Technology - PCBway
[1]: MCP73831 datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/20001984g.pdf
[2]: MCP73831 schematic symbol, PCB footprint, 3D model: MCP73831T-2DCI/OT footprint, schematic symbol and 3D model by Microchip
[3]: Electronic designing CAD software plugins: https://www.samacsys.com/library-loader-help
[4]: Altium Designer plugin: https://www.samacsys.com/altium-designer-library-instructions
[5]: Siglent SDM3045X multimeter: SDM3045X Digital Multimeters | Siglent Multimeter | DMM