Existing versions of Apple's Time Machine allows scheduled backups only when a Mac notebook's power cord is connected. It looks like this is going to change when OS X 10.5.3 is rolled out.

According to AppleInsider, developers testing pre-release builds of the new OS X Leopard update have reported that Time Machine will be getting a new option to allow backups even when a Mac notebook is running solely on battery power.

While this option will reportedly be disabled by default, users will be able to toggle it on via the "Options" button in Time Machine's system preferences.