Thermic S-PACK 4000 B schwarz
Therm-ic S-Pack 4000B batteries power Sidas and Therm-ic S.E.T. heated socks with three adjustable heat levels and Bluetooth control. This battery pair is intended for long days in the cold; actual runtime depends mainly on the heat setting and conditions of use.
Pickup available at Brucker Str. 49
Usually ready in 24 hours
SF Sports · Selection & advice
Therm-ic S-Pack 4000B
The Therm-ic S-Pack 4000B complements Sidas and Therm-ic S.E.T. heated socks, as well as compatible Therm-ic Fusion heated socks, when you want adjustable warmth over many hours. Two batteries power the socks separately, while the Heat Control App makes adjustment easier. Choosing is about more than the advertised maximum hours: well-fitting ski boots, dry socks and a heat setting matched to your needs remain essential for comfortable feet.
Technical specifications at a glance
Plan runtime around your day
The manufacturer’s figures of up to 23, 10 and 7 hours refer to different settings. The highest setting is therefore not the best choice for a full, long ski day. Start with a comfortable low level and increase it only when needed. Temperature, battery condition and usage affect achievable heating time.
Match the battery to the right sock
The S-Pack 4000B fits Sidas and Therm-ic S.E.T. heated socks, as well as compatible Therm-ic Fusion heated socks. The same brand alone does not guarantee a connection to another heated product. Check the exact sock version before buying; in particular, batteries for insoles and gloves are separate systems.
Control warmth and avoid pressure points
A heating system cannot fix a ski boot that is too tight. Poorly positioned socks, cables or folds can create additional pressure. Try the complete setup and route the connection as instructed for the socks. Steady, gentle warmth is often more comfortable in everyday use than continuous maximum power.
Who is Therm-ic S-Pack 4000B right for?
Choose the 4000B pair if you want long operating times and smartphone control. For an additional set for existing socks, check their compatibility first. The batteries are worn externally at the designated sock attachment and must not be squeezed into the tight boot cuff.
Use & selection
Before skiing: Charge both batteries, check the connections and test the desired setting before your first run. Your runtime reserve should suit the planned day.
After use: Disconnect the batteries before washing the socks. Splash resistance does not mean the batteries can be washed or submerged. Let connection areas dry before charging.
Storage: Follow the charging and storage instructions in the current manual. After a long break, test the system before the first training session; a battery left unchecked in autumn is not a reliable reserve for a full day.
Complete your setup
Why buy this product from SF Sports?
At SF Sports in Gilching, we discuss your intended use and existing equipment before recommending a model. Bring the items you want to use together to your fitting. This lets us compare differences in fit and handling directly and establish which addition is genuinely useful for you.
Questions before you buy
Are two batteries included?
Yes, this S-Pack 4000B package contains two rechargeable batteries.
Are heated socks included?
No, this product is the battery pair. Compatible heated socks are required separately.
Do they last 23 hours on the highest setting?
No. The manufacturer specifies up to 23 hours on level 1, up to 10 on level 2 and up to 7 on level 3.
Which app controls the heat?
The Therm-ic Heat Control App provides Bluetooth control.
Do the batteries also fit Sidas socks?
Yes. The S-Pack 4000B fits Sidas and Therm-ic S.E.T. heated socks and compatible Therm-ic Fusion heated socks. This does not imply general compatibility with every heated product from either brand; the correct sock system is what matters.
How are both batteries charged?
Using the USB-C charging accessories included in the package. Use a suitable power supply as specified in the instructions.
Can I wash the batteries with the socks?
No. Remove them before every wash and follow the socks’ care instructions.