The current control process of battery charger

The current control of the battery charger is one of the key aspects to ensure that the current is within a safe range and meets the battery specifications during the charging process. Control of current needs to take into account the type of battery, its chemistry, and the design of the charger to maximize charging rates while ensuring battery safety and longevity.

Current limiter design:

Battery chargers are usually equipped with a current limiter to ensure that the charging current is within the maximum allowed value specified by the battery. This limiter can be a hardware circuit or a software algorithm implemented by a microcontroller.

In the design, it is necessary to consider the rated charging current of the battery and the maximum temperature at which the battery can operate safely at this current.

Constant current charging mode:

During the constant current charging stage of the battery, the charger will continue to provide a fixed current to quickly charge the battery. This current value is usually a certain percentage of the battery capacity, such as 1C of the battery capacity (C is the multiple of the battery capacity).

Batteries commonly used in mobile devices, such as lithium-ion batteries, are often charged at a constant current near their maximum charge rate.

Current control algorithm:

Advanced battery chargers usually use current control algorithms to adjust charging current by monitoring the status of the battery in real time. This may involve precise measurement and analysis of battery voltage, temperature, resistance and other parameters.

The current control algorithm is also able to detect changes in battery status, such as an increase in battery internal resistance, to dynamically adjust the current during charging to prevent overheating and damage.

Security considerations:

In current control, safety is a key consideration. The battery charger needs to have an overcurrent protection function to promptly interrupt the current under abnormal conditions.

A high-quality battery charger will also consider the extreme conditions of the battery, such as overcharge, over-discharge, etc., and use current control to avoid these unsafe charging states.

The charger and battery work together:

Batteries and chargers typically work together, with the charger sending signals to the battery to understand its status and dynamically adjusting charging current based on the battery's response.

This collaborative work ensures reasonable regulation of current during different charging stages to maximize charging efficiency and battery life.