I have the A119 V3 with the HK3 wiring kit and have had no issues with battery. I haven't tested current draw but I believe I read somewhere it was something like 200mAh. I wouldn't worry about battery unless you have an old one on it's last leg. You can choose between 4 voltage selections on the HK3 so if your concerned with your battery you can set it to the highest cut off voltage.
IMO the A119 V3 is NOT a very good option if you want to use parking mode.
While in Auto Event detection or Time lapse modes when G-sensor triggered events are recorded they are placed in the Movie directory which is overwritten from the Normal Loop recording function. There is no distinguishable Flag, Lock, Protection or Notification presented to the owner unless they are sitting in their vehicle while parked. There is no "Lock" or "Protection" on those files so if you don't view them regularly they will be overwritten at some point depending on how large your memory card is.
The only parking mode that places G-sensor triggered events into a safe location, apparently protected from the overwrite routine is the Low Bit Rate Mode. So basically if you want to setup a camera to record constantly any camera with similar specs would do.
I've spoken of this design flaw in the A119 V3 thread and have been waiting for
@viofo to comment for a little over a week on this forum. I've also had ongoing ticket with Viofo support and have been waiting 5 days for a response from them to speak with their engineers. At this point it's seemingly becoming difficult to get them to acknowledge and address the issues.