There are various methods for recharging rechargeable batteries.
For example, in lead-acid batteries, it is trickle charging.
Trickle means little by little, and is a method of maintaining a fully charged state by continuously flowing a minute current that does not adversely affect the battery even after it is fully charged.
However, trickle charging is not recommended for lithium-ion batteries.
In the case of lithium-ion batteries, if the fully charged state is kept constantly, an issue will arise in which overcharging will occur and the capacity will decrease.
The CVCC method is recommended for lithium-ion batteries.
This is a method to manage and control both charging voltage and charging current.
At the beginning of charging, when the voltage is low CC charging will be done.
As the charge amount increases, the voltage increases, so when reaching the set voltage (for example 4.2V), the current is controlled to maintain the constant voltage (CV) while performing additional charging.
In this way, for charging the rechargeable batteries,proper management and control are required according to its type.