I've only had it a couple of weeks, but it's been so nice to not have to worry about my battery dying mid-day anymore. I can go two, two-and-a-half days now on a charge. I use my phone mostly for texting and web-browsing, some email, some Google Maps and Sky Maps, as a flashlight, a few non-intensive games; not a lot of phone calls. But with my old battery, same usage, I felt like I was doing pretty good if I still had 20% battery by the end of the work-day at 5ish.