PB and iBook battery question...

Hey folks,

I wanted to know what type of battery life you get from your PB, particularly the new 12" PBooks and iBooks.

I know that iBooks generally give you 4 to 5 hours of battery life, even if you keep the screen, HD, and sleep settings at fairly generous levels. My rev B 12" 1GHz Powerbook gives me 3h 20min battery life if I only use Word, and around 2h 45min if I use iTunes. That's normal battery capacity for a rev A and B 12" Powerbook. I want more.

The 12" PB's have a new battery, and people are reporting 5 hours of battery life, but on what settings? I don't remember the exact values, but the new 12" PB is rated at 50 Watt·hours. I think they were at 46 Watt·hours last month, which really doesn't seem to be much of a difference.

I want to buy a new 12" PB battery if it makes THAT much of a difference, but don't want to buy it if I'll only get 4.5 hours with all settings maximized for battery life. Actually, I would expect to get 4.5 hours with the way I'm using it now (screen down 4 notches from full brightness, sleep after 8 min, screen turns off after 5 min, etc), since people claim to get over 5+ hours with all settings set lower to conserve battery life.

And how are the other PB's and iBooks doing in terms of battery life right now?

Is it the 12" PB?

If it is, I was actually expecting to get around 3h 45min or so, since the new battery is only about 10% better, and yet people are telling me that it's over 5 hours. If the battery is improved THAT much, I want it.

I hear that the new 15" is slightly better than before, but not by much.