Therm-ic S-Pack 4000B Bluetooth batteries for heated socks, 2-pack
1 559 kr
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1 559 kr
Therm-ic S-Pack 4000B Bluetooth batteries for heated socks, 2-pack
Shipping from 0 kr · Choose your delivery option at checkout.
- 14-day right of withdrawal
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- Delivery all over Sweden
- 3-year right to complain
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For the longest days
Hunting, on the ice or on a multi-day trip you need heat for a long time. The 4000B lasts the longest.
On in seconds
Snap the battery onto the cuff and turn on the heat with the button or in the app.
Product FAQ
Which socks do the batteries fit?
The S-Pack 2400, 3000B and 4000B fit Therm-ic heated socks with S.E.T® or Heat Fusion technology, such as Heat Fusion One, Ultra Warm Comfort, Ultra Warm Performance, Ultra Warm Nordic and Bike Socks. Older Therm-ic socks like Heat Fusion Uni ND use the older S-Pack 700, 1200 and 1400B.
How do I look after the batteries?
Charge after each use; they can be charged at any level. Don't wear the socks while the batteries charge. Store them half charged, cool (5–20 °C) and disconnected, and top them up at least every six months. Never open the casing and don't use a damaged battery. Recycle worn-out batteries.
Is the heat safe, and can I sleep in them?
Do not sleep with the heat on. Start on level 1 or 2: Therm-ic advises against leaving level 3 on for more than a few minutes, as the skin can get too warm. Check regularly for redness. If you find it hard to feel heat and cold, for example with diabetes or poor circulation, or if you have sensitive skin, ask a doctor before using them. Children should only use them under adult supervision and on the lowest level.
Can the heat interfere with my avalanche beacon?
Therm-ic notes that, like any electronic device, the product can interfere with an avalanche beacon. Test your gear together before heading off-piste.
Can I take the batteries on a plane?
The batteries are lithium-ion, about 14.8 Wh each (calculated from voltage and capacity), well below the 100 Wh limit that usually applies in cabin baggage. Loose batteries go in your carry-on, not in checked baggage. Rules vary, so always check with your airline before you travel.
How fast will it arrive, and can I change my mind?
Delivery options and times are on our Delivery page. You have a 14-day right of withdrawal and a 3-year right to complain – see the Returns page.
Description
S-Pack 4000B is Therm-ic's longest-lasting battery pair for heated socks, with Bluetooth so you can control the heat in the Heat Control app.
With Heat Fusion socks one battery lasts up to 23 hours on level 1, 10 hours on level 2 and 7 hours on level 3, according to Therm-ic. With S.E.T® socks the figures are 20, 8 and 6 hours.
The batteries snap onto the cuff, are dust- and splash-proof (IP64) and charge with the included USB-C cable, both at once, in about 5 hours.
For multi-day trips, long hunts, ice fishing and anyone who wants heat from the first run to the last.
Features
- 2 batteries 3.7 V / 4,000 mAh with Bluetooth
- Longest heating time in the S-Pack range
- Up to 23 h on level 1 with Heat Fusion socks, according to Therm-ic
- App or button control
- USB-C charging, about 5 h; IP64
Specifications
| In the box | 2 batteries, USB charging cable (dual USB-C / USB-A), laundry bag |
|---|---|
| Battery type | Lithium-ion 3.7 V / 4,000 mAh (about 14.8 Wh each, calculated) |
| Heating time level 1/2/3, Heat Fusion (Therm-ic) | 23 / 10 / 7 h |
| Heating time level 1/2/3, S.E.T® (Therm-ic) | 20 / 8 / 6 h |
| Charging time (Therm-ic) | About 5 h |
| Charging | USB-C, both batteries at once |
| Protection | Dust- and splash-proof, IP64 |
| Bluetooth | Yes, controlled with Therm-ic's Heat Control app |
| Conformity | EU declaration of conformity (Directive 2014/53/EU) according to Therm-ic |
| Fits | Therm-ic socks with S.E.T® or Heat Fusion |
| Warranty (Therm-ic) | 2 years |
Delivery and returns
You choose your delivery option at checkout:
- PostNord – collect at a service point, 2–4 working days – 0 kr
You have a 14-day right of withdrawal from the day you receive your item. Contact us within 14 days if you want to cancel your purchase.
Read more about returns and withdrawalWarranty and complaints
You have a three-year right to complain about faulty goods under Swedish consumer law. If something is wrong with your item, contact our customer service and we will help you.
Contact customer service