Cron is badly behind the capabilities of the Win XP task scheduler in some areas. If the prelink monster runs when I am on batteries, then it reduces my battery time by about 25%. Seriously. Hence I do not want prelink to run if on batteries. I could file this as a bug against prelink, but I think that cron should have this ability. It needs to associate flags with jobs, which then decide whether execution should go ahead. One flag would be "do not run if on batteries". When the time comes to run the job, cron would then detect that we're on batteries (via HAL?) and refuse to run the job. This message looks relevant too, as it suggests a wholesale replacement of vixie-cron with a particular alternative: https://www.redhat.com/archives/fedora-devel-list/2006-June/msg00583.html
*** This bug has been marked as a duplicate of 190268 ***