Sounds like what my Thinkware branded one blurts out, word for word. If it is the same, there's a voltage threshold in the camera settings (configured by mobile app or on a PC).
I find the camera says this a lot sooner if I've had the door open for a little while (various lights come on) or some other aspect of the car on. I've never found it necessary to immediately charge the battery (car still starts fine).
However, in this cold temperature and with it drawing power from the battery even when off, it's worth trickle charging to keep it topped up. These hybrids don't have big batteries.
Another option on Thinkware is an option regarding a time limit for parking mode recording. Even if the battery voltage is healthy, it'll turn off after 4, 8, 12 or 24 hours, and you can choose that.