How Electric Cars Safely Pause Charging When You Want to Unplug

A system for electric vehicles that safely pauses power flow when a driver signals they want to disconnect the charging cable, preventing electrical arcing or damage.

What it covers

This patent describes a safety mechanism for electric vehicles that manages the transition between charging and unplugging. When a user presses a button on the charging cable to initiate disconnection, the system pauses the flow of electricity while keeping the internal safety relays closed for a short, predetermined time. If the user changes their mind and cancels the disconnection request within that window, the car instantly resumes charging without needing a full system restart. If the time expires or the cable is physically removed, the relays open to safely cut power.

What it doesn't cover

• —Does not cover the physical design of the charging plug or the locking mechanism itself.
• —Does not cover wireless or inductive charging systems that lack a physical cable connection.
• —Does not cover charging systems that immediately cut power without a pause-and-resume grace period.
• —Does not cover software-based battery management systems that monitor cell temperature or voltage.

The clever bit

The invention keeps the relay switches closed during the pause, treating the user's 'disconnection command' as a temporary state rather than an immediate power-off event, allowing for a seamless resume if the user accidentally hits the button or changes their mind.

Why it matters

Managing high-voltage power in electric vehicles is dangerous because pulling a plug while current is flowing can cause electrical arcing, which damages the charging port and the cable. This patent provides a standardized, safe 'handshake' between the user's intent to unplug and the vehicle's electrical system, ensuring the hardware is protected during the transition.

Real-world examples

• 1.Nissan LEAF charging systems
• 2.Standardized J1772 charging station protocols
• 3.Electric vehicle onboard charging controllers