Street guardian - Viofo ASO allow all the way down to 11.8 volts cut off, but you should not go there with a lead acid battery, 12.2 Volts i think is said to be OK and should not cut into battery life.
When i changed battery on my 2012 car a few years ago, it look and worked fine, but a camera had problems that went away with the new battery
But before that i never used parking guard on any dashcam, so for sure not their fault my original battery only lasted 8 years.
I think someone in here also posted once that he had a battery replaced in a shop, and a few weeks later it was toast, but that was manufactory flaw on the battery not deep cycling.
Just like i have had memory cards in good brand names, barely being able to fill them 1 time before they died on me,,,,, some times you get a dud,,,,,,,, which are also OK with cheap stuff, but people like NASA ASO, well their expensive rockets bloody well better work and work perfect.
If i was in need of long duration parking guard, i would put a #2 battery in my car ( plenty room for it where AC would be installed, and even a big battery not like the 50 Ah one i put in ( 45 AH factory )
And then i would probably go for a AGM battery as they handle deep cycle better as i understand it.
And then of course have a charge / discharge splitter so your car battery are safe.
A car battery charge pretty damn fast as i understand it, so 30 - 40 - 50 A, and then like phones in slow once it near 100 %
Dedicated dashcam power packs only charge with 15 A or so at the MAX, and they too slow to a trickle when approaching 100% charge, so with same capasity as a AGM battery, you would have to drive more to recharge a dedicated power pack.