Battery Fujitsu CP809642-XX LIFEBOOK U728 U727 U729

The Fujitsu CP809642-XX LIFEBOOK U728 U727 U729 battery is a replacement internal battery compatible with selected Fujitsu LIFEBOOK ultrabooks. Designed to match the original equipment specifications, this 4170 mAh battery restores portable power to Fujitsu U728, U727 and U729 models, enabling continued mobile use and stable operation when mains power is unavailable.

Advantages

This battery offers a capacity of 4170 mAh to provide extended runtime compared with a depleted cell, while maintaining compatibility with the laptop's power management system. It is manufactured to fit the physical dimensions and connector requirements of the LIFEBOOK U728, U727 and U729, ensuring correct installation and reliable contact. The unit is intended as a direct replacement and supports normal charging cycles and system reporting for battery level and health.

Suitable for (tasks / use cases)

• Replacing a worn or failing internal battery in Fujitsu LIFEBOOK U728, U727, U729
• Restoring mobile runtime for business travel and remote work
• Maintaining uninterrupted operation during short power outages or while moving between outlets
• Keeping a backup battery option for technicians and IT maintenance

Key specifications

• Battery type: internal lithium-ion replacement battery
• Capacity: 4170 mAh
• Compatibility: Fujitsu LIFEBOOK U728, U727, U729 models
• Form factor: model-specific internal pack designed for direct fit and connector alignment

How to use

Power down the laptop, disconnect any external power source and remove external peripherals before replacing the battery. Follow the manufacturer's service instructions or a qualified technician's guidance to open the laptop base, disconnect the existing battery connector, and install the Fujitsu CP809642-XX battery in the corresponding compartment. Reconnect the battery cable, reassemble the device, then connect the AC adapter to perform an initial charge as recommended by the laptop's power management guidelines. After installation, verify battery recognition in the operating system and allow a full charge-discharge cycle to calibrate battery level reporting.

Recommendations

Use the battery only in compatible Fujitsu LIFEBOOK models listed. Charge the battery using the original or manufacturer-approved AC adapter. Avoid exposure to extreme temperatures and physical damage. If you are not experienced with internal laptop repairs, have the battery replaced by an authorized service provider to prevent damage to the device and ensure safety.