yesterday it took me by reall surprise when i tried to turn on My laptop compaq 610 after about 36 hrs but it refused to turn on without plugging in the charger. after turning it on A/C power when i checked the battery status it was zero. i m dead sure when i turned it off last time the status was 90+. i checked the battery health it was in GOOD health. more over the battery back up has dramatically reduced since last few days. it was consistently giving me 4+ hrs but now it is giving 3 hrs along with system hang in problem frequently? what could be the reason? it is still under warranty!