Car cam with no external power option?

On the default vehicle usage setting with my car in the garage and no detection events, the car cam turn off after about 12 hours. If there is no other external battery option, this become less of a security device and more of a drive cam. I bought it for security just like all my other Ring cameras, particularly when I need to leave it parked at an airport parking lot for a few days or a week. If I can't plug this into an external battery pack for extended use, it will likely be going back to Ring in the next few weeks.