Good batteries that do what they want

The batteries serve their purpose.
They are used in a cordless phone "Siemens Gigaset". Once the old batteries had to be definitely changed, I decided on the Ansmann batteries.
These have the standby time of my softphone increased noticeably again - and thus they have exactly served its purpose.

However, they were not, as originally stated on the back of the package, at the beginning of "same use".
A battery tester yielded a virtually "empty" performance with the new batteries.
I first had to leave for a while in the cradle the phone with the new batteries, only after that the loading bar was regularly on "full".