Batteries Therm-ic S-Pack 4000B are the highest-capacity batteries for Therm-ic heated socks. They offer up to 23 hours of heating, three heat levels directly on the battery and more precise control over Bluetooth in the Heat Control App on your smartphone. They charge over USB-C and resist splashing water and dust.
Level 1: up to 23 hours
Level 2: up to 10 hours
Level 3: up to 7 hours
Bluetooth control – regulate the heat precisely in the Heat Control App on your smartphone.
Three heat levels – you can also set the intensity directly on the battery.
USB-C charging – the supplied cable has two connectors for charging both batteries at once, which takes about 5 hours.
Durable construction – the batteries resist splashing water and dust.
Secure connection – patented snap buttons ensure a firm connection to the socks.
The batteries are designed for heated socks from the Therm-ic brand with S.E.T. or Fusion technology, for example Ultra Warm Comfort S.E.T, Ultra Warm Performance S.E.T or Ultra Warm Nordic S.E.T. If you do not need such a large capacity, take a look at the S-Pack 3000B or S-Pack 2400 batteries. Our article on how to choose heated socks for winter activities or the socks category may help too.
Store the batteries in a cool place at 5 to 20 °C.
Before long-term storage they should be about half charged.
Charge and discharge the batteries regularly.
Disconnect them from the socks before storing or cleaning.
Clean them with a soft cloth.
