A backup BlackVue battery pack is not a requirement, however, in most cases, an external battery pack such as the B-130A can provide additional time in parking mode for the camera to monitor and record. It is important to note that there is a limited storage capacity with either your vehicle's battery or a backup battery and this might not be able to provide full 24/7 coverage.  

As every vehicle differs so greatly, it is not possible to say for sure whether a backup BlackVue battery would be required to utilise parking mode, however, we are finding this more commonly to be required in some European and hybrid vehicles.