The device charges the battery in three phases: pre-charge, constant current, constant voltage. At the beginning of a charging cycle, the device checks the battery voltage and regulates current/voltage accordingly.
For 2S to 4S applications, when the battery voltage is below minimum system voltage VSYS_MIN() the charger is in pre-charge status. When EN_LDO=1b, charge current is the lower value of 384mA and CHARGE_CURRENT() setting. The 384mA clamp current is to prevent overheating the BATFET. When EN_LDO=0b, the charge current is programed through CHARGE_CURRENT() register.
For 1S applications, when the battery voltage is below minimum system voltage VSYS_MIN() but larger than 3V the charger is in pre-charge status. When EN_LDO=1b, charge current is the lower value of 2A and CHARGE_CURRENT() setting. When the battery voltage is below 3V the charger is also in pre-charge status. When EN_LDO=1b, charge current is the lower value of 384mA and CHARGE_CURRENT() setting. The clamp current is to prevent overheating the BATFET. When EN_LDO=0b, the charge current is programed through CHARGE_CURRENT() register. When the battery voltage is above minimum system voltage VSYS_MIN() and below max charge voltage CHARGE_VOLTAGE(), the charger is in constant current (CC) mode. The charger regulates the charge current at CHARGE_CURRENT() setting.
When the battery voltage reaches max charge voltage CHARGE_VOLTAGE(), the charger is in constant voltage (CV) mode. The charger regulates the battery voltage at CHARGE_VOLTAGE() setting. The charge current is determined by the charger, which is lower than the CHARGE_CURRENT() setting.
When the charge current drops below termination current (determined by user), the host can stop charging by programming CHARGE_CURRENT()=0.
The above battery charging profile is illustrated below.
