Charging Gun

A charging gun (charging plug / charging connector) is the handheld terminal at the end of an electric vehicle (EV) charging system—spanning battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs)—that connects directly to the vehicle's charging inlet. Beyond serving as a high-voltage, high-current conduit for power transfer, it is also the core hardware interface for control pilot signalling, safety handshaking, and data communication between the EV and the charger. The electrical insulation, mechanical locking mechanism, and ergonomic design of the charging gun directly dictate user convenience and operational safety during daily charging.

Core Technical Architecture and Working Principle

The technical construction of a charging gun primarily comprises high-voltage copper alloy terminals, signal control pins, an electronic locking latch, heavy-duty cable harnesses, and integrated temperature sensors: 

Power Terminals and Communication Handshaking: 

Internally, the charging gun houses main power pins for electricity delivery (live and neutral lines for AC charging; positive and negative pins for DC fast charging) alongside auxiliary pins for low-voltage control signals (such as CC and CP pins). Upon plugging the gun into the vehicle inlet, the Control Pilot circuit first initiates an electrical "handshake" protocol verification. Only after confirming that insulation resistance is normal and the physical connection is secure will the charging station close its main contactor to deliver high-voltage power to the terminals, ensuring the connector remains completely de-energised until fully engaged.

Integrated Temperature Monitoring and Safety Disconnection: 

During high-power DC fast charging, currents running into hundreds of amperes generate substantial Joule heating across the cable and contact interfaces. Modern charging gun heads are fitted with integrated, high-precision temperature sensors (such as NTC thermistors) to monitor contact-resistance thermal build-up in real time. If temperatures exceed predefined safety thresholds, the system immediately commands the charger via the communication link to throttle the current or shut down output entirely, preventing the plastic housing from melting or triggering thermal runaway.

Safety Specifications and Physical Limitations

Strictly Prohibit Using a Charging Gun with a Cracked Casing, Worn Cable Insulation with Exposed Copper, Corroded Terminals, or Water Ingress for High-Voltage Charging (Prohibiting Using Damaged or Worn Charging Guns): 

Charging guns carry high voltages of several hundred volts alongside heavy currents. Physical damage must never be overlooked. If the insulation layer fails or the terminals become damp or deformed, high-voltage arcing and short circuits can occur instantly upon energisation, presenting severe risks of electric shock or fire. A visual inspection of the connector head must always be conducted before each charging session.

Strictly Prohibit Yanking the Cable to Forcibly Remove the Charging Gun During Charging, or Twisting It Before the Lock Is Fully Disengaged (Prohibiting Forcibly Pulling Cables or Twisting Locked Guns): 

Charging guns and vehicle inlets interface via an electromagnetic locking pin or mechanical latch. Forcible removal is strictly prohibited. Tugging the cable before the charging cycle has ended and the lock has retracted can snap internal signal wires and damage the locking socket, resulting in the vehicle failing to recognise the charger in subsequent sessions or causing the gun to become jammed and locked in place.