Charging is at a constant current, till the battery terminal voltage reaches 14V, after which charging is continued at a constant voltage of 14 V till the charging current becomes zero. As I understand, this is because the output voltage is not so 'strong' to maintain its value from high drawing current.
At this stage, the battery voltage remains relatively constant, while the charging current continues to decrease. Charging Termination: The charging process is considered complete when the charging current drops to a specific predetermined value, often around 5% of the initial charging current.
Here is a general overview of how the voltage and current change during the charging process of lithium-ion batteries: Voltage Rise and Current Decrease: When you start charging a lithium-ion battery, the voltage initially rises slowly, and the charging current gradually decreases. This initial phase is characterized by a gentle voltage increase.
Going below this voltage can damage the battery. Charging Stages: Lithium-ion battery charging involves four stages: trickle charging (low-voltage pre-charging), constant current charging, constant voltage charging, and charging termination. Charging Current: This parameter represents the current delivered to the battery during charging.
The charging process reduces the current as the battery reaches its full capacity to prevent overcharging. For instance, a lithium-ion battery may charge at a constant current of 1C until it comes to around 70% capacity, after which the charger switches to a regular voltage mode, tapering the current down until the charge is complete.
Charging Termination: The charging process is considered complete when the charging current drops to a specific predetermined value, often around 5% of the initial charging current. This point is commonly referred to as the “charging cut-off current.” II. Key Parameters in Lithium-ion Battery Charging