How Does a Car Charger Work?

First take off the battery, the charger has two output lines, one is red (positive), the other is black (negative), the battery has two lead electrodes, the electrode side is usually printed with + number is positive, the negative electrode. General car battery has two kinds of voltage, 12V and 24V, car is basically 12V, big truck has 12V or 24V.

Charging mode of automobile starting battery:

Charging takes 20 hours, such as 12V60Ah charging mode: constant voltage current limiting mode is used for charging, constant voltage 14.8V current limiting 15A charging for 16 hours, and then 3A constant current charging for 4 hours, a total of 20 hours.

A fully charged battery can be judged by the following phenomena:

1) the battery produces a large number of bubbles, both appear "boiling" phenomenon;
2) The terminal voltage rises to the maximum value and does not rise within two hours;
3) The electrolyte rises to the highest level and does not rise again within two hours.

Vehicle-mounted charger refers to the vehicle-mounted charger that is powered by car battery (12V for car, 24V for truck) and is widely used in the field of lithium battery charging for various portable and hand-held devices.

Such as: mobile phone, PDA, GPS and so on; Vehicle charger should not only consider the actual demand of lithium battery charging (constant voltage CV, constant current CC, OVP), but also take into account the harsh environment of vehicle battery (transient peak voltage, system switching noise interference, EMI, etc.); Therefore, the power management IC selected by the car charging scheme must simultaneously satisfy the switching power supply chip with high voltage resistance, high efficiency, high reliability and low frequency (conducive to EMI design).