Lars please post your project so we can check it.
It is not really my project, it is the example project which came with the PSoc Creator 3.2, The only changes i made to the project is to enable the battery measurement and to disable the battery simulation. This was done by one variable in the bas.h file.
And then i selected Pin 3.7 as input pin for the ADC Component. Thats all.
Of course i have another project where i have difficulties with the ADC. That was the reason, why i wanted to ensure that the config is correct and started over with the example project from Cypress (Bluetooth HID Keyboard).