Ok i think i found the BIG BUG on the system that causing the RARE troubles with the Battery ... I was very happy with my Battery life with the 1.01 os ... Anyway i decided to get more life by buying another BL-5J battery ... Just in case i need it one day of too much N900 doing things ... the same day that i upgrade OS... i recieve the new battery ... So, to my knowledge, a new battery came with a 50% of charge ... But to my surprise when i put the new battery the system show me 100% of charge ... anyway i thought rare but ok ... may be the battery came fully charged? ... so i continue using without problem ... The same day after a few hours ... the Battery indicator display 100% yet? ... i thought ... wow amazing battery or amazing os upgrade! .. but suddenly ... alarm!!! and red indicator! ... So... just at may be 1% or 2% of the real battery charge the system recognize that real charge and showed ... the new battery really was at 50% of charge not at 100% that display the os indicator... Then! ... ok i connected the charger .. and leave the phone totally OFF to get a good charge ... After a few hours ... ok Green light on .. fully charged ... right? Ok turn it ON and the bat indicator show 100% ... ok good ... Then again ... heavy use ... few hours later .. the indicator show about 70% .. i thougt (wrong again) .. oh nice bat or nice upgrade... Nope ... i installed a third party app bat indicator... and that app showed near dead battery (as must be) and the OS indicator display near 50% ... So conclusion... the new battery NEVER was fully charged, only to 50% ... and i can't fully charge because the OS think that it's already full at the 50% ... And here is the most rare of all things ... this behavior ... do not occur with the original Battery ... ... may be because that battery was fully charged many times with the older OS version? ... the original battery could be charged to 100% without problem and i can get nice time of usage and both indicator show the same info ... OS and 3rd party bat indicator .. Please! some body test this... use 2 batteries ... and test! There you will understand why some people talk about quick drain... itīs because the OS never fully charge those batteries and it's lying displaying WRONG bat info level ... So, there ir a serius HUGE problem with the OS about Battery levels and charging ... don't know why this happend on the upgraded 1.1 ... but i can't confirm how it was using 2 batteries with 1.01... may be the same? may be not? Ok.. OS guys ... work on that!! bye!