PowerWarehouse RWFFJ laptop battery Dell XPS 16 9640 11.7V 8504mAh

Compatible replacement for Dell XPS 16 9640

This PowerWarehouse RWFFJ battery replaces the original J8FK9 pack in Dell XPS 16 9640 and XPS 9640 laptops. It is a direct-fit component for owners whose factory cell has lost usable runtime. Buyers needing a different voltage or form factor will not be served by this unit.

Steady discharge at rated voltage

The cell delivers a nominal 11.7V across its 8504mAh capacity, so sustained workloads draw current at a stable potential rather than a decaying curve. This behaviour supports consistent performance during long sessions away from mains power. Heavy continuous loads will still deplete the pack in line with its rated capacity.

Low thermal signature in normal use

As a lithium-ion pack with no active cooling, it generates minimal heat during typical office or media tasks and adds no audible noise. Power draw follows the laptop’s own management circuitry, staying within the original design envelope. The 12 month warranty covers defects in materials and workmanship.