Try installing the amd driver for your processor for PowerNow!. This page
should help. Also I think that 'always on' is probably going waste battery life (wouldn't want to keep the cpu at 100% all the time) so try something like speedswitch
and choose dynamic switching from the speedswitch panel so that the clock speed will be increased to 100% only if it is really needed. Oh and for the lcd becoming less bright you would have to use your keyboard (or other keys that should be on your laptop) to make it bright again .. you probably know this but just in case you don't.
So now you can really do what you wanted to do without really wasting the battery as well