As a combination of two batteries consecutively unusable!

The batteries are only to be used individually. As a combination of two batteries consecutively, they are not useful because they can not contact each other.
The contacts are ca.0,5 mm below the insulation. Thus, between the contacts -If the batteries connected in series always Video- 1mm air between the contacts and thus no current can flow.
Because I wanted to use the batteries for a flashlight, when 2 batteries are located behind each other, I can not use them and therefore they are going back!