There are two ratings on a laptop battery, Voltage (V) and
Milliamp-hours (mAh). Voltage is the rate at which energy is drawn
from a battery and Milliam-hours represents the capacity of the
battery.
The Voltage rating has to MATCH that of the original battery or as
recommended by the laptop computer manual. Using a battery with a
different voltage setting can damage the laptop.
Since the mAh rating represents the capacity and correalates to the run
time of the battery. If the rating is higher than the original battery,
then the replacement battery will run for a longer time and if the
rating is lower then the replacement battery will run for a shorter
time.