This is a brand new genuine Dell DW842 battery for the Precision M6400 and M6500 models.This DW842 battery is rated 11.1 volts and 7800 mAh and will typically last 3 hours on a full charge.

This DW842 battery si for a high performance engineering workstation. Consequently, the power consumption of your laptop is higher than most. As a result, you can expect about 2-3 hours of run time with this DW842 battery when new, depending on your energy use.