I think a spare battery is an essential for any phone, and was pleased that this one came at a reasonable price. After a couple of weeks, my impressions are (a) excellent service and prompt delivery, (b) the battery seems to do the job. Of course, I can't give a long-term reaction, but it seems to last a comparable length of time to the original in my Motorola Defy. So it's certainly four stars at the moment, and I suppose that could go up to five or down to three depending on what happens in the long term. But for well under a tenner I'm perfectly happy.