Sorry, my german is awful... let me answer in english :)
First of all, congratulations on Your new watch! :)
The 9750 needs two different type of batteries, two CR1216 and one SR621. I've replaced them a long time ago, so I'am not sure which one is which one, but to check it it's simple: Count the batteries in the remote control's side, and they'll be the ones You need :)
Good luck! :)