70mai a800s with external battery bank

[imix]

Hi All,

Not sure if anyone has previously tried this or attempted.

My Current setup:
70mai a800s with back camera
70mai UP03 (USB C version)

Hardwired accordingly and functions as it should with parking mode. However my BMW bms system keeps shutting down all power including remote functions due to excessive battery drain. which also stops all power going into dashcam.

My future setup/plan

I have an external power bank (i understand the risk of having power banks in a car. I have it in a fireproof box under the rear trunk storage compartment. My use case is, car will be packed underground without direct exposure to heat or cold ) would like to use it to power the dash cam. However when i live it powered on via battery bank , it will keep running in continuous recording mode (I get about 3-4 days of recording). Is it possible to modify USB C cable to enable parking mode/time laps recording?

Any advice would be appreciated.

Thanks

 

[imix]

++ Bit more info

I'm currently powering the battery bank using DC-DC converter connected to the car's cigarette lighter connector (ACC mode) . Battery only chargers via ACC and shuts off charging (DC-DC converter power input) after car goes into sleep mode , charging stops.