Power adapter, electronic equipment, battery charging system and method

A battery charging apparatus, wherein

• the battery charging apparatus comprises a power adapter and a charging control assembly, the power adapter charges a battery of an electronic equipment via a communication interface of the power adapter, the charging control assembly is arranged in the electronic equipment, both the charging control assembly and the battery are coupled with the communication interface of the power adapter via a communication interface of the electronic equipment, the charging control assembly is also coupled with electrodes of the battery so as to detect a voltage of the battery, and the communication interface of the electronic equipment is a USB interface;
• during charging the battery, the power adapter is configured to:
• first charge the battery in a regular charging mode;
• when an output current value of the power adapter falls within a regular current range for a predefined time period, perform a quick charge inquiry communication with the charging control assembly;
• after receiving a quick charge command sent by the charging control assembly, adjust an output voltage according to battery voltage information fed back by the charging control assembly;
• if the output voltage meets a quick charge voltage requirement predefined in the charging control assembly, adjust an output current and the output voltage according to a quick charge mode so as to charge the battery, in which the charging control assembly simultaneously introduces direct current from the power adapter to charge the battery.