A "CC battery" isn't a specific type of battery per se, but rather refers to how a battery is charged using the Constant Current (CC) charging method. This is a crucial stage in charging many types of rechargeable batteries, particularly lithium-ion batteries.
Understanding Constant Current (CC) Charging
During CC charging, the charger delivers a constant, predetermined amount of current to the battery, regardless of the battery's voltage. This continues until the battery voltage reaches a specific level, often around 80% of its full charge capacity. The provided reference states: "Constant current (CC) charging initially allows the full current of the charger during the BULK stage to flow into the battery regardless of the battery state of charge or the temperature until the battery terminal voltage reaches a pre-set steady state. The battery is now in a state of charge of 80%."
Think of it like filling a glass with water. During the CC phase, the water (current) flows at a consistent rate.
Stages of Battery Charging
CC charging is typically the first stage of a multi-stage charging process. Common stages include:
- Trickle Charge (if needed): A very low current used to wake up deeply discharged batteries.
- Constant Current (CC): As described above, the main charging phase where the current is kept constant.
- Constant Voltage (CV): Once the battery reaches a certain voltage (e.g., 4.2V for a lithium-ion cell), the charger switches to constant voltage mode. The voltage is held constant, and the current gradually decreases as the battery nears full charge.
- Float Charge (Maintenance): In some cases, a small "float" charge is applied to maintain the battery at full capacity without overcharging.
Why is CC Charging Important?
- Faster Charging: Delivers the maximum safe current for rapid initial charging.
- Controlled Charging: Prevents damage by limiting the current flowing into the battery.
- Efficient Charging: Ensures the battery charges effectively up to a significant portion of its capacity.
Example: Charging a Lithium-Ion Battery
Imagine charging a lithium-ion battery in your smartphone. The charging process typically involves:
- The charger starts in CC mode, pushing a constant current into the battery (e.g., 2 Amps).
- As the battery charges, its voltage increases.
- When the voltage reaches the target level (e.g., 4.2V per cell), the charger switches to CV mode.
- In CV mode, the voltage is held at 4.2V, and the charging current gradually decreases until it reaches a very low level, indicating the battery is fully charged.
