No full power

The battery came as described - as orginal Samsung product in blister.
According to the production date (June 2014), the battery was already about half a year old and deeply discharged (I thought Lithium ion batteries are delivered always half full).
Unless the battery is working and the NFC function is guaranteed, but the battery does not nearly what the Original battery could. After a few minutes after loading the percentage indicator of the battery drops to 96% and so that never stops.
The battery lasts about 2 days by now - which is enough for me. My old battery was already bloated and denied sometime at 50% the service completely, so you never knew how long you can get away with the phone.