A charger usually consists of a transformer, a rectifier, a filter, and a control circuit. The transformer converts the AC voltage to the required low voltage, the rectifier converts the AC power to DC power, and the filter is responsible for smoothing the output voltage to ensure the stability of the charging process. The control circuit is responsible for monitoring the battery status and regulating the charging current.

Charging process
The charging process is divided into several stages:

Initial charging stage: When the battery power is low, the charger charges at a higher current to help the battery recover quickly. This stage usually lasts for several hours, depending on the capacity and remaining power of the battery.

Constant voltage charging stage: When the battery voltage reaches the specified value (about 14.4 volts), the charger switches to constant voltage mode. At this time, the charging current will gradually decrease to keep the battery within a safe voltage range to prevent overcharging and battery damage.

Trickle charging stage: When the battery is close to being fully charged, the charger enters the trickle charging mode, outputs a lower current, and keeps the battery voltage stable. This stage ensures that the battery does not discharge naturally when it is not used for a long time.

Monitoring and protection
Modern 12V lead-acid battery chargers are usually equipped with intelligent monitoring systems that can monitor battery voltage and temperature in real time to prevent risks such as overcharging, short circuit and reverse connection. When the battery is full, the charger will automatically stop charging or switch to maintenance mode to ensure the safety and long life of the battery.

Types of chargers
There are many types of 12V lead-acid battery chargers on the market, including smart chargers, constant current chargers and fast chargers. Smart chargers are popular because they have automatic adjustment charging strategies and multiple protection functions.

The working principle of 12V lead-acid battery chargers is both simple and complex, involving multiple electrical components and charging strategies. Understanding its basic working principle can help users better select and use chargers, thereby improving the efficiency of battery use and extending its service life. When choosing a charger, it is recommended to choose a product with smart charging function to ensure a safe and efficient charging experience.