A battery indicator is a special accessory for lithium batteries that measures the condition of the battery very precisely. This accessory is compatible with Arduino (or a compatible board such as Dasduino) and provides precise monitoring via the I2C interface. The main functions include measuring the current voltage in millivolts, the state of charge in percent and the remaining capacity in milliampere-hours. It is suitable for 1S batteries. https://elecena.pl/product/25977680/333065-developer-boards-battery-indicator-for-4-2-v-batteries 2024-05-26 https://elecena.pl/product/25977680/333065-developer-boards-battery-indicator-for-4-2-v-batteries 2025-04-07