Interesting modules found on aliexpress etc

Lithum Battery Charger with Protection TP4056



  • price about $0.2 - 0.3
  • usually set to Icharge = 1A, modify R3 to change the current
  • add cap (1000uF) when using 5V solar as power source, otherwise will charge very slowly (probably because it starts oscilating)
  • TP4056 datasheet
  • DW01A datasheet

ESP 8266 modules

see its own page