Constant live fuse dashcam Thinkware F750

[mike6688]

I see from other threads that a dashcam can be wired to fuse 85 to come on and off with ignition.  However, I have a third cable on my hardwire kit that needs a permanent live.  Which fuse would be best for this in the passenger fuse box.  Also what size/type of piggyback fuse would be needed for this.  Camera is a Thinkware F750 with hardwire kit and car is a Mk 3.5 Ford Focus 1.5 TDCi Titanium.

I'm wiring the camera in to activate the parking mode recording; there is an option to adjust the settings so that the camera automatically stops recording if it detects the cars battery falls below a certain voltage.  Can someone also tell me what voltage this would be best set at?

 

Thank you in advance.