I hardly use my laptop with power cord detached, so over the last few years, the battery has been only used for a less than 100 cycles I would estimated. But now, the battery can barely support one hour. I think despite the battery is hardly used, it just decayed over the time. So overall, for 30 dollars investment, it is an OK deal. If you use it as a backup, i.e. you not really going to depend it for mobile work.See full review