I'm pretty sure it requires 5V only over USB. There are reports of some newer multi-output voltage USB batteries damaging labradars.
As to the Bluetooth it's possible it was RF but I think current limiting may have been in play as well. I recall having issues getting a cellphone to charge using thinner USB cables in my car, changing the 12V to USB adapters had no effect. Once I used the original USB cable, bam it worked as expected.
EDIT:
Detailed post on a unit smoked by one of these non-standard USB battery packs:
https://www.snipershide.com/shooting/thr...s.7014287/
As to the Bluetooth it's possible it was RF but I think current limiting may have been in play as well. I recall having issues getting a cellphone to charge using thinner USB cables in my car, changing the 12V to USB adapters had no effect. Once I used the original USB cable, bam it worked as expected.
EDIT:
Detailed post on a unit smoked by one of these non-standard USB battery packs:
https://www.snipershide.com/shooting/thr...s.7014287/