Disappointed, but very serious seller

This battery worked normally for about three weeks. But it then deteriorated rapidly. A month after the purchase, it loses 80% of its charge during the day, even without using the phone. By using it, I have to recharge one or even two times during the day. In short, cheap to buy, but it is money thrown out the window.
Avoid.

Update 5/18/2014:
Finally, I add two stars. The battery has been some bursts and is reset to function properly for a week, but then released. Perhaps by insisting a little, it could still be used, but I do not trust. For cons, I would point out the excellent after-sales service from the manufacturer, who seems to sincerely regret my problems, which makes me think that maybe I just had the misfortune of hitting a wrong number . They spontaneously offered me an exchange, then, after my refusal, a refund, without discussion. Congratulations to them!
So maybe it is worth trying this battery, you will probably have more luck than me. And if you have the same luck than me, know that you will not have any problem with the seller.