Li-ion battery charger (Baofeng)

Baofeng UV-5R battery smart charger.

Original charger was not working so i have re-made it to better nicer cooler smart battery charger:)

It has polarity protection, overcurrent protection(fuse and current measurring) and overvoltage/overcharge protection.

When battery is fully charged(i have set it up to 8.3V, you can change it if you want) it is disconnected and just monitored. If battery voltage drop to some treshold(you can set it up in source code) it is starting to charge again.

There is some warning when battery error or when battery is deeply discharged.
You can see current and voltage on OLED display, there is some LED ring(Neopixel) animation as well and you can here integrated buzzer(piezo) as well.

Arduino code is attached same as Fusion 360 file.
Arduino code just rename extension from .txt to .ino

I have programmed it for Arduino Nano, you can use any MCU if you fit it inside(or just edit Fusion 360 source code.

I have used battery contact from original Baofeng charger.
Please use original PSU from Baofeng or use some according to specifications of used Step Down converter.

Please see connection of self recovering fuse and Schottky diode on attached pictures.

Electronics:
Arduino Nano
OLED SSD1306
INA 226
Piezzo buzzer
WS2812 LED ring(24 LEDS)
Step Down Converter
Relay board
Self recovering fuse
Schottky diode

PIN 6 - LED RING
PIN 9 - Piezo
PIN 8 - Relay board

https://www.youtube.com/watch?v=1oryCFOcHXs

Prusa i3 MK3
0.2
20 infill
PLA
no supports