Batteries for heated socks - S-Pack 4000B

The S-Pack 4000B battery pack provides up to 23 hours of heating time for compatible Therm-ic and SIDAS heated socks, with Bluetooth control through the new Therm-ic app. With up to 23 hours of heat, the S-Pack 4000B offers the longest battery life in the current S-Pack range. It features three heat levels, allowing you to adjust the heat to suit your needs. The batteries feature a durable splash- and dust-resistant design, while the snap fastenings ensure a secure connection to compatible Therm-ic heated socks. The USB-C charging system allows for quick and convenient charging, and the included charger allows both batteries to be charged at the same time. What's Included 2 × S-Pack 4000B rechargeable batteries 1 × USB-C charger for simultaneous charging Heating Duration Level 1: up to 23 hours Level 2: up to 10 hours Level 3: up to 7 hours Key Features Bluetooth control through the new Therm-ic app Three heat levels Up to 23 hours of heating time Longest battery life in the current S-Pack range Splash- and dust-resistant construction Secure snap connection to compatible heated socks USB-C charging Charges both batteries simultaneously Therm-ic App Compatibility The S-Pack 4000B is compatible with the new Therm-ic app. For the 2026/27 season, the new Therm-ic app is compatible only with the S-Pack 3000B and S-Pack 4000B. Previous-generation Bluetooth batteries, including all C-Pack models, continue to use the Therm-ic HC app. Compatible Heated Socks The S-Pack 4000B is designed for use with Therm-ic and SIDAS heated socks featuring S.E.T.® or Fusion technology. Important: The new Ultra Warm Sensor S.E.T® is only compatible with the S-Pack 3000B and S-Pack 4000B. Therm-ic Powersocks Heat Men Therm-ic Powersocks Heat Ladies Therm-ic Powersocks Heat Fusion Therm-ic Powersocks Heat Fusion One Ultra Warm Comfort S.E.T® Ultra Warm Performance S.E.T® Ultra Warm Sensor S.E.T® — S-Pack 3000B and 4000B only SIDAS Ski Race S.E.T® SIDAS Ski Heat LV SIDAS Ski Heat MV