How a Battery Heats Itself in the Cold for Better Performance

This patent describes a rechargeable battery that can warm itself up in freezing temperatures by temporarily increasing its internal electrical resistance, then switching back to normal operation for full power.

What it covers

The patent details a rechargeable battery designed to work well in all climates. It includes a standard internal resistance (R1) for normal operation and a second, higher internal resistance (R2) created by a special "resistor sheet" located inside or next to a battery cell (Claim 1, 2). When the battery is cold, below a certain temperature (T1), a "switch" connects this resistor sheet to the battery's terminals (Claim 1, 13). This causes current to flow through the higher resistance (R2), generating heat internally to warm the battery quickly (Abstract). Once the battery reaches a normal operating temperature (T2), the switch disconnects the resistor sheet, and the battery operates with its lower, normal resistance (R1), delivering full power and energy (Abstract). For example, an electric vehicle battery could use this to rapidly warm itself on a freezing morning, ensuring optimal range and acceleration from the start.

What it doesn't cover

• —Does not cover battery heating systems that use external heating elements, rather than an internal resistor sheet (Claim 1 specifies the resistor sheet is "within or adjacent a cell").
• —Does not cover batteries that generate heat through chemical reactions without an additional, switchable high-resistance electrical circuit (Claim 1 defines R1 and R2 electrically).
• —Does not cover systems that lack a switch to change between a high-resistance heating mode and a lower-resistance operating mode (Claim 1 requires "a switch configured to electrically connect or disconnect").
• —Does not cover batteries where the high-resistance element is not connected via an additional terminal (Claim 1 specifies "at least one high resistance terminal").
• —Does not cover batteries that only have a single, fixed internal resistance, regardless of temperature.

The clever bit

The innovation lies in integrating a dedicated, switchable heating element directly inside the battery cell. This allows the battery to use its own electrical power to rapidly and efficiently warm itself from within, rather than relying on external heaters, and then seamlessly switch to optimal performance once warm.

Why it matters

Batteries, especially lithium-ion types, perform poorly in cold weather, losing capacity and power. This patent offers a solution by allowing the battery to quickly warm itself from the inside, significantly improving performance in subfreezing conditions. This is crucial for electric vehicles, drones, and other battery-powered devices that need reliable operation across diverse climates, extending their usability and lifespan.

Real-world examples

• 1.Electric vehicle battery packs designed for cold climates
• 2.Drones operating in arctic or high-altitude environments
• 3.Outdoor energy storage systems in regions with harsh winters
• 4.Portable electronic devices used in subfreezing temperatures