6 months top - then problems

Battery has 6 months fulfilled his service and was as good as the original in anything - from the 300 mAh more I have not noticed anything, but it was not important to me.
After 6 months, my phone began regularly 5-6x to plunge a day - but only if the Polar Cell battery was inserted (I use the mobile phone extensively and must often during the day to change the battery), with the original battery had / I have not the problem.
Conclude that it is in the Arctic Cell Battery.
Außerden can the Polar Cell Battery recently no longer on the charging station to charge (the original battery already) and is no longer recognized by SGS4 in 1 of 4 trials when inserting.
I am the Meining a battery should last longer than 6 months, therefore only 2 stars.