macosxhints - Get the most from X!: "Authored by: serres on Sun, Nov 17 '02 at 03:04AM
pmset - modify power management settings
since 10.1.4 (?) we have a command line utility called 'pmset', see
% man pmset
with it you can modify the relevant power manager related settings available in mac os x (i looked at the source intensively). it even has some commented out stuff for future use like the 'wake from sleep at some date' setting we had in mac os 9. for some non-understandable reason these are not implemented in the mac os x power manager library :(
you should also use this utility to modifiy the PowerManagement.xml file.
i think what's *very* important to save battery power is to enable the 'Reduce Processor speed' setting."
pmset must be run as root. If you type pmset alone you get a helpful example.