IC Used: TP4056 (Lithium-ion battery charger IC)
Charging Voltage: 4.2V ± 1% (the regulated voltage for a fully charged Li-ion battery)
Charging Current: Adjustable, typically 1A (through a resistor on the board, commonly 1.2A or 0.5A depending on the resistor chosen)
Input Voltage: 5V (usually via a micro-USB or DC jack)
Charge Termination: The IC stops charging once the battery reaches 4.2V, with a typical cutoff current of 10% of the charge rate.
Battery Protection:
Overcharge Protection: Stops charging if the battery voltage exceeds 4.28V.
Over-discharge Protection: Prevents discharging below 2.5V or 3.0V (depending on the protection IC).
Overcurrent Protection: Typically supports short-circuit protection and overload protection for the battery.
Over-temperature Protection: Some boards may include temperature sensors to prevent charging or discharging if the temperature is too high.
Red LED: Indicates charging (when the battery is being charged).
Green LED: Indicates a fully charged battery.
Micro-USB Input: Most of these boards use a micro-USB port for input power, commonly 5V.
Output Terminals: The board typically has positive (+) and negative (-) terminals for connecting the battery (often labeled as B+ and B-).