MichaelK, nice catch, thanks. I haven't dug deep into battery power management, as my batteries seem to last per specification; it hasn't itched, so I haven't scratched (the surface of) it.
GKrellM has the capability for setting battery alerts, but they seem to be based on "time remaining," rather than percentages. According to this page
, you can also set up alerts on Conky and have them warn you in various ways with the proper scripts.
I have used the battery meter function of GKrellM, but not set up alerts.