PDA User Manual

Chapter 5: Configuration
Power Management Properties
102 Ikôn Rugged PDA (Windows CE 5.0) User Manual
5.5.5.3 Suspend Threshold And Estimated Battery Backup
The Suspend Threshold adjustment tells the system when to shut down when the battery
drains. If left at the default value, Maximum Operating Time, the Ikôn will run until the
battery is completely empty; the RAM is only backed up for a short period of time. If you
choose Maximum Backup Time, the Ikôn shuts off with more energy left in the battery so
RAM can be backed up for a longer period of time.
The Estimated Battery Backup is the amount of battery power that has been reserved or set
aside to protect data until a charged battery can be installed in the Ikôn. When the battery ca-
pacity is depleted up to the Estimated Battery Backup reserve specified in the Suspend
Threshold menu, the Ikôn shuts off automatically and uses the reserve power to preserve the
Important: Selecting Maximum backup time will reserve approximately 20% of the
battery capacity for memory backup. Once the battery is drained, the system
RAM memory is lost and the unit must boot.
In most real-time transaction environments this is not a problem (it only
takes a few seconds to boot). Batch transaction environments, where data is
not saved to a non-volatile memory (such as an SD FLASH card), may
need to pay particular attention to this parameter. Psion Teklogix does not
recommend the storage of any valuable data in system RAM.
The Ikôn Windows CE 5.0 environment does not store any critical data in
RAM (such as the registry or file system).
If the user's application does not save data to RAM, Psion Teklogix recom-
mends keeping the Suspend Threshold setting as low as possible to
maximize battery run time.