There is no option or whatsoever. Just install and your battery will be monitored. When the PPC is connected to a charger, the uptime will be reset to zero. The uptime will start count whenever the charger is disconnected.

If you also want to monitor your PPC's memory status, you can try BatteryTimePlus, another free plugin which is not only monitor battery usage, but also display current memory status.

Tap or tap&hold on BatteryTime (on Today Screen) will display a popup menu which allows a user to choose from:

• Close Menu: Closes the popup menu. Or just tap anywhere else other than the popup menu will close it too.
• Reset uptime. Sets the current uptime value to zero
• Today Plugins: This will open the Today Plugin setting control panel
• Alarm Clock: Opens the Clock-Alarm setting control panel
• Backlight Brightness: Opens the backlight brightness setting panel (probably only works on some iPaq PPCs)
• Hardware Buttons: Opens the Program Buttons setting panel
• Power Control: Opens the Power setting panel (not work on some PPCs)
• Running Programs: Show current running programs

Because each Pocket PC has its own hardware control, Backlight Brighness and Power Control might not work on some PPCs. Based on my own testing, Backlight Brighness setting works on both iPaq 2210 and 4150. Power Control works on most PPCs but doesn't work on iPaq 2210 (don't know why).

It'll be very appreciated if you could try these menu items on your PPC and send me the feedback about these two items. Many thanks.

BatteryTime should work on all PPCs with ARM (including XScale) CPUs, Pocket PC OS 2002 and up. It only takes 11KB memory. 

Installation:

Just copy the BatteryTime.cab file (in the downloaded zip file) to your PPC, and click on it with any file explorer to install. If it doesn't show up on your Today Screen, just do a soft reset, or use Start->Setting->Today and the "item" tab to set it up.

Upgrade:

Please disable BatteryTime and do a soft reset. Then install the newer version following the above Installation instruction.

Uninstall:

Disable BatteryTime in Today Plugins setting then uninstall with any uninstaller.

BatteryTime is FREE!

Version History:

• version 1.5 power and backlight settings are compatible with more PPC models
• version 1.4 Running Program menu item added. Warning before reset uptime added
• version 1.3 fixed popup menu location problem. added some more menu items. reduced CPU processing time
• version 1.2 popup menu added. now startup time much faster
• version 1.1 hour display bug fixed
• version 1.0 initial release on July 13th, 2004