When in standby on battery power, the ThinkPad will not enter hibernation mode automatically via the timer. If, for example, on battery power, you have your ThinkPad set to suspend in 5 minutes and hibernation after 15 minutes, the machine will enter standby at 5 minutes but will not enter hibernation after 15.

Any of the following ThinkPad systems running the Windows Vista and XP operating system :

• ThinkPad R60
• ThinkPad R61
• ThinkPad T60
• ThinkPad T61
• ThinkPad X60
• ThinkPad X60 Tablet
• ThinkPad X61
• ThinkPad X61 Tablet
• ThinkPad Z60
• ThinkPad Z61
• ThinkPad R400
• ThinkPad R500
• ThinkPad SL series
• ThinkPad T400
• ThinkPad T500
• ThinkPad X200
• ThinkPad X200 Tablet
• ThinkPad X300
• ThinkPad X301
• ThinkPad W500
• ThinkPad W700
  

This is normal behavior. When entering hibernation, the contents of system memory are written to a file on the hard drive. The size of this file will approximately equal the amount of installed memory on the machine and it may take over a minute to write this data to the drive. If the ThinkPad were being carried while in standby and the hibernation timer became active, the drive could be written to while the system is being jostled.

Active Protection can guard against this but could also prevent the system from entering hibernation. If you prefer to have your ThinkPad go into hibernation on battery, rather than standby, set the hibernation timer to a lower value than the standby timer.