[Novice] Tips on minimizing power consumption - XIAO ESP32C3

[msfujino]

The battery pad on the back of XIAO is for 3.7V LiPo batteries only.
The charge current of the on-board charge controller is 370mA for C3, 120mA for C6, 110mA for S3, 200mA for MG24, and 100mA for nRF52840.
Unless a LiPo battery has a special built-in feature to limit the charge current, it will be charged at the above current. In general, it is recommended that a 180mAh battery be charged at 180mA or less. If a 180mAh battery is charged with C3, it will be charged at 370mA, which may reduce battery life.
The following link may also be helpful.

Charging characteristics of XIAO_nRF52840 and XIAO_ESP32C3

XIAO_nRF52840 and XIAO_ESP32C3 have a built-in charging function, but since the circuit diagram was not disclosed, I assumed that they have the same circuit. I was curious and measured the charging characteristics. They are completely different, XIAO_nRF52840’s charging current can be set to 50mA or 100mA by firmware, but XIAO_ESP32C3’s is fixed and very large at 370mA, so I need to be very careful when using small capacity batteries. [XIAO_Charge]

The following document may be helpful regarding the possibility of LED lighting during sleep.

ESP32-C3 Technical Reference Manual
5.9 Pin Hold Feature
32 LED PWM Controller (LEDC)

ESP32-C3 Series Datasheet
3.4.7 LED PWM Controller