Hey everyone,

I'm looking for someone to help me modify an existing PCB design I found online. The current design uses AA batteries, but I’d like to adapt it for a single 18650 Li-ion cell and add some other power-related features.

💰 Budget:

• 25 € on completion
• +25 € bonus if the updated design works successfully after testing
• I plan to manufacture ~100 of these, so future work is likely

🔧 What I need done:

• Swap AA battery power for 18650 Li-ion
• Add TP5100-based charging circuit (so it can handle higher DC input voltage)
• Include a battery protection circuit (e.g. DW01 + FS8205) if needed
• Enable charging through USB, ideally while still using the CP2102 USB-to-Serial
• Replace 2.54 mm battery header with a JST PH-2.0
• Add a physical switch to completely cut off battery power
• Check the schematic/PCB for any weak points or potential improvements

🧾 Files available:

• Schematic image for reference
• Full project (.brd, .sch)

https://ibb.co/xn4P6ZY

If you're experienced with power management, charging ICs, and prepping designs for fabrication (JLCPCB or similar), let’s talk. Happy to answer any questions or provide the files privately.

Thanks!