I owe an HP zv5160us for one year now and have almost always used it pluged to the power. I could say that I used it with the battery maybe... 5 times?... Know, when I try to use it unplugged, the battery lasts less than 1/2 an hour... I already completely discharged and recharged it several times as recommeneded in the manual and stuff but still the same... I guess it is broken and I need to buy a new one but I dont know why it happend so fast.... Is there any way to be sure that is really done before I spend some bucks in a new battery?