Suspend to RAM works since firmware 1.5. This mode, also dubbed "sleep", automatically switches of all but RAM and the hardware detecting the pressing of a key until such time a key is pressed. It's hard to express in hours - I never read a book for 24 hours straight - but the gain sounds realistic to me.
(Unfortunately it is negated by the battery getting old and getting old extra quick due to the deep draining occuring occasionally.)
|