Chosen Solution
jlW_2015 try the Deutsche iFixit. Die haben den gleichen guten Service und haben wahrscheinlich auch die Batterie :-) Check on here for the battery and for more help contact them on here Also, remember that there is/was a recall on the batteries. Check with Apple on here to see if your phone qualifies. Maybe Apple in Krautland ;-) can fix you up.
New US laws imposed have greatly restricted any international shipping on batteries, Even in the US they can only be shipped by ground. I would do as OldTurkey suggests and use the EU store in Germany. https://www.ups.com/media/news/en/ca/int…
check reviews on amazon and ebay. those are going to be your 2 best bets when it comes to getting something half way reliable. unless you go through a supplier of some sort. just make sure you read reviews on the seller and usually amazon and ebay are both good about getting your problems fixed with botched orders. good luck!