Since I got my xoom my thunderbolt has been a bit neglected and I only have to charge it every 45-48 hours. It makes me wonder how long the extended battery would last.
if i'm home all day or somewhere there is wifi, i could go all day and not think about charging. otherwise i can usually get about 12 hours, maybe a little more depending on use. i'm not sure i need an extended battery.
Being that this is my first "smart phone" I was kinda depressed that the battery life was so short. I moved from the envy2 where I charged once a week or so to charging everyday with the Tbolt. I work third shift and plug in before bed and it usually lasts all day (9pm until 1pm or so) I have used many of the battery saver tips on this forum.