Battery Problem Solution Galaxy S2 - this battery: China scrap

--Nachtrag 10.10.2014--
Property me now bought an original electronic spare battery with Conrad. Although costs about 21, but I have under normal use (few emails, little Internet, little Telfonate, read articles on the Internet, GPS recording of jogging tour) evening about 30% battery left. So there seems to be an original battery with Conrad. So my S2 is again like the first day available.
And important: Google Now swallows vast amounts of battery, so disable prefer! Just as the location services!
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I had problems with the battery life of my Galaxy SII, which not even held by a whole day with little use in early summer. Shortly before, I had carried out the update to Android 4.1.2.
After nearly two years of use of smartphones I hattte the battery typed and ordered these "original" battery on Amazon. Delivery and price were great, but the battery life was the new battery is not better.
In various forums I read about battery problems SII after updating to Android 4.1.2 and pushed the short battery life on the operating system. Here I have researched for weeks, as the problem could be solved. Jatzt I after more than 3 months found the solution: reset the unit to factory settings, format SD card completely and again my original battery (which I received when you purchased the SII have) used. Lo and behold, problem solved. My battery lasts even with frequent use again by two days. The replacement battery is not even keep the same system constellation by one day, so I only advise: Stay away!
Where to buy a real original battery, I have not able to find out.