As Chris said, this can be accomplished using the “Locale Power Power Source Plugin.” Simply add a Battery condition to detect the battery level, and a Power Source condition to detect being unplugged. Please note that this plug-in requires Android 2.0 or later.

At long last Locale 3.0 introduces the Calendar condition to detect events on your Google Calendar, Exchange Calendar, or any other calendar supported by Android.

While Locale 3.0 is available for Android 2.2 or later, the Calendar condition requires Android 4.0 or later. To learn more about Locale 3.0, please see our release notes here http://blog.twofortyfouram.com/post/19303488607/locale-3-0

A 3rd party developer has created a plug-in called “Locale Lockscreen Plug-in” that implements this feature request.

This plug-in can be found by choosing the “Get Plug-ins” menu item within Locale.

This is basically implemented in Locale 1.0. Locale 1.0 intelligently schedules situation updates. If a situation contains both a location and time condition, then Locale won’t schedule a wakeup until the time condition is met. Once the time condition is met, then location will be checked periodically.

You might still see Location is being checked rarely even while the Time condition isn’t met, as Locale may do a full refresh every once in a while. (For example, when launching the Locale UI, and sometimes when waking the screen, or during the transition between other situations.)