HP 421 Notebook-PC - Manual (Page 82)

If a computer will be unused and unplugged from external power for more than 2 weeks, remove the
battery and store it separately.
To prolong the charge of a stored battery, place it in a cool, dry place.
NOTE: A stored battery should be checked every 6 months. If the capacity is less than 50 percent,
recharge the battery before returning it to storage.
Calibrate a battery before using it if it has been stored for one month or more.
Disposing of a used battery
WARNING! To reduce the risk of fire or burns, do not disassemble, crush, or puncture; do not short
external contacts; do not dispose of in fire or water.
Refer to the Regulatory, Safety and Environmental Notices for battery disposal information.
Replacing the battery
Computer battery life varies, depending on the power management settings, programs running on the
computer, display brightness, external devices connected to the computer, and other factors.
Battery Check notifies you to replace the battery when an internal cell is not charging properly, or
when the battery storage capacity has reached a “weak” condition. A message refers you to the HP
Web site for more information about ordering a replacement battery. If the battery is possibly covered
by an HP warranty, instructions include a warranty ID.
NOTE: To ensure that you always have battery power when you need it, HP recommends
purchasing a new battery when the storage capacity indicator turns green-yellow.
70 Chapter 5 Power management