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Fogstar Energy Green 21700 Battery (4000mAh)


Delivery & Shipping

All orders placed through the Mix Labs wholesale website are processed and dispatched in the UK.

United Kingdom

DPD (Next Working Day Delivery) in the United Kingdom is £6.00.

Parcelforce (Next Working Day Delivery) in the United Kingdom is £6.00.

DHL (Next Working Day Delivery) in the United Kingdom is £6.00.

We also offer your choice of courier above as Free Tracked Shipping for all orders over £350 (ex VAT).

DHL (Saturday Delivery) in the United Kingdom is £12.00. 

Channel Islands

DHL (1-2 Working Days) in the Channel Islands is £14.00.

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Fogstar Energy FS4000 21700 Battery

The Fogstar Energy FS4000 21700 battery is built for vapers who need high-performance power for demanding setups. With a 4000mAh capacity and a robust 25A continuous discharge rate, this rechargeable cell is ideal for sub-ohm vaping and high-drain devices.

Engineered with durability and safety in mind, the FS4000 is a flat-top, non-protected battery, recommended for use in regulated devices with built-in safety features. As part of Fogstar’s Energy Series, each cell undergoes strict quality testing to ensure reliable performance and long-lasting power.

Key Features

  • Battery Type: 21700 Lithium-Ion
  • Capacity: 4000mAh
  • Continuous Discharge Rate: 25A
  • Voltage: 3.6V
  • Rechargeable, Flat-Top Design
  • Non-Protected Cell
  • Perfect for Sub-Ohm and High-Drain Applications
  • Designed for regulated vape devices

Safety Information

  • Only use according to manufacturer’s instructions.
  • Charge with a dedicated Lithium-Ion charger.
  • Never leave batteries unattended while charging.
  • Keep away from children and animals.
  • Inspect wraps and insulators regularly for damage – repair or recycle if compromised.
  • Expected cycle life: 200–500 charges before noticeable capacity drop-off.
  • Do not crush, incinerate, or modify the cell.

What's in the Box

1 x Fogstar Energy FS4000 21700 Battery

Important Notes

Always confirm compatibility with your device before use. For maximum safety, replace worn batteries promptly and recycle responsibly at end of life.