Plug, electrical connector and terminal device

An electrical connector, comprising a first wire, a second wire and a plug, one end of the plug being fit into an output port of the terminal device while the other end of the plug being connected to the vehicle battery through two wires so as to enable the terminal device to detect or charge or discharge the vehicle battery, the plug comprising:

• an insulating housing;
• a first terminal, arranged in the insulating housing;
• and
• at least one pair of second terminals, arranged in the insulating housing, each pair of the second terminals being distributed in central symmetry with the first terminal as the center;
• wherein:
• the first terminal is opposite in polarity to the second terminals;
• the first terminal is connectable to a terminal of the vehicle battery of the same polarity as the first terminal via the first wire;
• the at least one pair of second terminals are connectable to the other terminal of the vehicle battery of the same polarity as the at least one pair of second terminals via the second wire;
• when the plug is fit into the output port, the first terminal is connected to one of a positive electrode and a negative electrode of an internal battery in the terminal device of the same polarity as the first terminal, and the at least one pair of second terminals are connected to one of the positive electrode and the negative electrode of the internal battery of the same polarity as the second terminals, so that the positive electrode and the negative electrode of the internal battery are connected to the vehicle battery via the plug and the two wires;
• the plug is fit into the output port in either of a first direction and a second direction, the first direction being at 180 degrees from the second direction with the first terminal as a rotation center;
• and
• the first terminal being connected to the first wire which is connectable to the terminal of the vehicle battery of the same polarity as the first terminal, and the at least one pair of second terminals being connected to the second wire which is connectable to the terminal of the vehicle battery of the same polarity as the second terminals.

A terminal device for detecting a vehicle battery, the terminal device comprising an internal battery, the terminal device being provided with an output port, the output port comprising:

• a base,
• a fourth terminal, arranged on the base;
• and
• at least one pair of fifth terminals, arranged on the base, each pair of fifth terminals being distributed in central symmetry with the fourth terminal as the center;
• the fourth terminal is opposite in polarity to the fifth terminals;
• wherein the fourth terminal is connected to one of a positive electrode and a negative electrode of the internal battery, and the at least one pair of fifth terminals are connected to the other of the positive electrode and the negative electrode of the internal battery;
• and
• when the terminal device detects the vehicle battery, the fourth terminal is connected to a terminal of the vehicle battery of the same polarity as the fourth terminal, and the at least one pair of fifth terminals are connected to a terminal of the vehicle battery of the same polarity as the at least one pair of fifth terminals.