I have the original battery so I would say about 2 years old. I know batteries lose there capacity over time but this is ridiculous. I also notice that I also notice I cant get an accurate reading of how much use time I have left. Use time flucuates from 7hours to 3 to 4hours yet idle time stays at 10 days. However if it dies and reboots the battery will be at half way. Go figure. What do you think it is the battery? ps I get 10 minutes heavy use.