Battery and Charger Fieldmann FDUZ 79040 — Li‑Ion 4000 mAh

Fieldmann FDUZ 79040 — Li‑Ion 4000 mAh is a cordless tool battery with an integrated charger solution that provides portable power for compatible FAST POWER 20V series devices. Using Lithium‑Ion technology and a rated capacity of 4000 mAh, this battery is intended as a replacement or spare power source for garden and DIY equipment. The cell chemistry offers stable output across the discharge cycle, a minimal difference in performance between full and near‑empty charge, low self‑discharge and protection features that reduce the risk of overload, overheating and deep discharge.

Advantages

The Li‑Ion chemistry ensures consistent voltage and balanced performance during long work periods while remaining lightweight compared with older battery types. The 4000 mAh capacity extends runtime for tasks such as mowing, trimming or portable drilling. The battery is compatible with all machines from the FAST POWER 20V battery series and can be charged at any state of discharge without memory effect. Built‑in protections help preserve cell life and reduce the chance of damage from overcurrent, excessive temperature or deep discharge, and minimal self‑discharge keeps the battery ready after storage.

Suitable for

• Garden tools: cordless lawn mowers, trimmers and leaf blowers of the FAST POWER 20V series
• DIY and workshop tools: drills, drivers and screwdrivers compatible with FAST POWER 20V
• Replacement battery for prolonged outdoor tasks or as a spare pack for multi‑battery workflows

Key specifications

• Battery type: Lithium‑Ion (Li‑Ion)
• Nominal voltage: 20 V (FAST POWER 20V series compatibility)
• Rated capacity: 4000 mAh
• Integrated charger solution for convenient charging
• Protection features: overload, overheating and deep discharge protection
• Low self‑discharge for extended storage readiness
• Compact, lightweight construction for portable use

How to use

Insert the Fieldmann FDUZ 79040 battery into a compatible FAST POWER 20V device until it clicks into place and follow the tool manufacturer’s instructions for operation. If the battery includes an integrated charger interface, connect it to the specified power source and charge according to the indicator or charger instructions. The battery can be charged at any time regardless of charge level; avoid exposing the battery to extreme temperatures during charging or storage. After use, remove the battery from the device if prolonged storage is intended and store it in a cool, dry place.

Usage recommendations

To extend service life, avoid deep discharges whenever practical, keep the battery and device contacts clean, and use only compatible chargers and tools from the FAST POWER 20V series. Do not expose the battery to fire, strong impact, or prolonged high temperatures. If the battery becomes hot, emits unusual smell or shows visible damage, discontinue use and follow local recycling or disposal regulations for lithium batteries.