I got the part, unfortunately with the wrong plug on the charger - thought ich..so as someone in front of me.
Unfortunately, the seller has not reported on my request, I was eventually brave and curious, and have easy times screwed the plug. Behold, including a regular "German" plug is revealed.
The term "in the desktop charger" unfortunately is not true - it's just the case with Steckerlader 4x1800er AA batteries.
So do not despair if in doubt, but "tinkering" ;-)