My dashcams wont power through battery back

[Andyke]

Hello, i recently switched from driving a Golf V to a Volvo V50, had a Viofo a129 pro duo with a Cellink Battery B pack + extension. Which worked out perfect. However, with the Volvo i cannot Get any power to the dashcam through the batterypack.
I’ve tried:

1. charge / drive with the battery pack on 5V and off until the battery indicated «full». Then tried to plug in the camera. No power..
2. Tried a BlackVue b124 batterypack. The camera got power but were constantly shutting off and on.
3. Tried a Nextbase 612GW with the B124, same issue as nr 2.
4. Plugged the dashcam into the cigar outlet, worked perfect, but not through the battery packs.

Notice that the setup was all good in the Golf V, but not in the Volvo?? Any ideas? Shouldnt be a issue with the car brands should it?