USB timer switch?

[Noebuhdy]

Ran into an issue where the hardwire kit in my car causes the battery to drain flat, which makes no sense initially because it has the cutoff voltage set to no less than 12.0V
But turns out that there's a energy draw in the room-interior circuit (accessory).
Anyway, went back to the idea of using a 20,000mAh usb battery to imitate parked mode but this tends to deplete the battery approximately 10 hours, depending on settings. I don't know if there's a dashcam setting that can stop recording after a certain time while not in parked mode.
Then the idea came about using a usb device that can turn off everything after a set time, say 4:00 hours after parking, so the setup would look like,

[USB battery] -> timer switch (set to 4hrs) -> dashcam.
then obviously after 4 hours, the dash cam powers off as well as turn the battery off.
Is there such that can work?

 

[Ralph2]

How would the USB timer know when to start the sequence.. unless you manually started it every time. On top of that, most USB ports are not powered once the car is turned off.. I'm sure something could be invented but.. it's complicated

 

[Dashmellow]

You can purchase inexpensive 5V USB and hard wire 5V countdown timer switch relays on eBay that would probably work for this purpose but as @Ralph2 points out you would likely have to start it when you leave your parked vehicle. It might be made to work with a suitable power bank if you don't use 12V from your vehicle. These things handle a wide range of voltages.

DC 5V 12V 24V Digital LED Cycle Timer Delay Switch Turn Off/On Time Relay Module​

$4.85 USD + shipping

DC 5V Countdown Delay Timing Timer Turn OFF Time Counter Relay USB Switch Module​

$4.90 USD + shipping.