How Batteries Charge Fast in the Cold Without Damage

This patent describes a smart battery system that uses an internal heater to warm itself up for quick, safe charging, even when it's freezing outside.

What it covers

This patent describes a system for fast charging batteries, especially in cold environments, without damaging them. It uses a special "ohmically modulated battery" (Claim 1) which has an internal heating element, called a "resistor sheet" (Claim 1), built right into or between its cells. The system includes a "temperature sensor" (Claim 1) that constantly checks the battery's temperature. A "controller" (Claim 1) then uses this temperature information to decide whether to charge the battery normally through its "low-resistance terminal" or to activate the internal heater by routing current through a "high-resistance terminal" (Claim 1). For example, if the temperature sensor detects the battery is too cold, the controller switches to the high-resistance terminal, which warms the battery using the resistor sheet before or during charging, allowing for faster and safer charging.

What it doesn't cover

• —Charging systems that do not use a battery with a dedicated "high-resistance terminal" and an internal "resistor sheet" for heating.
• —Battery heating methods that rely solely on external heaters or ambient temperature control, rather than an internal, switchable resistor.
• —Charging protocols that do not dynamically switch between a low-resistance path and a high-resistance path based on temperature input.
• —Batteries without the specific internal resistor sheet configuration, where one tab connects to the high-resistance terminal and the other to a low-resistance terminal (Claim 1).
• —Systems where the controller does not determine the charging path based on temperature sensor input.

The clever bit

The innovation lies in integrating a dedicated "resistor sheet" directly into the battery cell or between cells, accessible via a separate "high-resistance terminal." This allows the battery to intelligently self-heat using its own charging current, controlled by a switch and temperature sensor, rather than relying on less efficient external heating or simply slowing down charging in the cold.

Why it matters

Fast charging is essential for electric vehicles and portable electronics. However, charging lithium-ion batteries too quickly at low temperatures can cause "lithium plating," which permanently damages the battery and reduces its lifespan. This patent offers a solution to safely enable fast charging in cold conditions, which is critical for user convenience and battery longevity in many applications, such as electric cars operating in winter climates.

Real-world examples

• 1.Electric vehicle battery packs
• 2.Electric bus batteries
• 3.Industrial robots and drones operating outdoors
• 4.Power tools used in cold environments
• 5.Consumer electronics (smartphones, laptops) in extreme cold