• Sold out
    New
Sold out

Batteries for heated socks - S-Pack 4000B

For heated socks

3 heat levels

Up to 23 hours of heat

Bluetooth

$349.95
$349.95
Sold out

The S-PACK 4000B is the most powerful battery in the range. Bluetooth technology allows you to remotely manage your heat level via your smartphone. Up to 23 hours of heat.

SKU : T41-0102-700

  • 100% satisfaction guaranteed 100% satisfaction guaranteed
  • Shipment in 72/96 hours Shipment in 72/96 hours
  • Secure payment Secure payment

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

S-Pack 4000B battery heating duration chart

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.

Technical characteristics

  • Heating time

    23hr

  • Colors

    Black

  • Connected

    Yes

  • Type

    Batteries & heating accessories

  • Activities

    Ski