I purchased this to replace the original battery in my 5230. It seemed O.K. at first but then died without warning (as other reviewers have found) after about a day. I am not a heavy user. The original battery still lasts over 2 days, despite being over 2 years old. Looking closely at this battery I don't think it is genuine NOKIA, the hologram looks wrong. I did not return the battery as it was so cheap, but I don't (can't) use it anymore. Got a very good genuine (and higher capacity) from ASDA mobile for a reasonable price in the end which I am very happy with.