Quite obviously experiences do vary widely, depending on a lot of factors. That said, the main factors for power consumption with the 5500 are:
1) Display illumination. Its level is the most important influence on battery life.
2) WLAN cards. These are usually hungry little buggers that will suck your battery dry almost as much as the display lighting.
3) The LCD. It's amazing how much power just the display refresh will use.
4) The CPU speed. Believe it or not, the CPU is a rather minor factor in the 5500 system design (i.e. it's ranked 4th for a reason ). But obviously its clock speed will have a certain influence, especially when the other factors are taken care of.
So what can be expected with a new, fully charged battery? My personal experiences range (as I already mentioned in another recent thread ) from anything around 45 minutes to 8+ hours.
The former is typical for streaming video playback via WLAN with maximum lighting and the CPU overclocked, the latter audio playback from SD-Card, no CF adapter, CPU heavily underclocked with light and LCD disabled.
A few more examples: about 80 minutes websurfing with max. light; roughly 2 1/4 hours at the lowest setting (both with WLAN, obviously).
Without WLAN, you can easily add an hour to those values, giving up to 3 1/2 hours. Without light (i.e. outside in broad daylight) you can even get a little more. If you underclock the CPU in those conditions, you will get a noticeable gain on top of that.
Last but not least, if your application allows it (audio playback being the most obvious), disabling the display altogether will give you that ultimate last kick in battery life
Obviously, battery life will decline with age, so getting a new battery every once in a while is advised if you need maximum independance from a mains lead -- and obviously a spare, fully charged battery can come in very handy.
Best regards,
Chris.
