Just registered to give the answer:

The hardwire kit does not work for me because I want to use a powerbank for parking mode so that I do not drain the car battery and can record for a long time.
Btw: my viofo A119 V3 consumes 273 mAh (per hour) in driving mode and with h265 codec.

Prerequisite: you need to enable parking mode in the menu (e.g. auto event detection).

If GND is connected to USB pin 4 (ID) the cam will enter parking mode.
If VCC -> 5k Ohm resistor -> USB pin 4 (ID): the cam will enter driving mode/exit parking mode.

For this to work the cam must be first powered up in driving mode - this triggers the automatic switch by sensing the ID pin.

The switchover is instantaneous, not the motion detection based switching which also does not work.

I used three relays to perform the switchover from car battery while driving and powerbank when parked. If someone is interested I could provide a schematic.

Thanks to viofu. Based on the information provided above, I have used an even simpler wiring method described at:


Viofo­wirings.jpg
 
Last edited:
@RGeB Thats a viable solution if the powerbank can be changed in the vehicle which is not the case for my 200 Wh beast :)
Only thing that is important: the powerbank must support power output while charging - I think this is called passthrough.

Btw. I measured the resistance between the ID Pin and GND, a pulldown resistor of 6.3 kOhm seems to be in place in the dashcam so in fact the relay does not need to actively connect GND to the ID pin.
 
HI, I'm thinking about this but from another angle:

a129pro ------- 3 wire kit¬ ---------------------------------------------------------------------------------------------------------------------------ACC.
...... . . ....... ........ . . . ........|--------12v/5v boost ------ standard 1000mah USB power bank ------5v/12v usb converter -------ACC

that way the power bank charges when car is operational, but as batt+ is not connected, the cam won't drain when off. 3 wire kit is connected to acc as normal but batt+ is connected to my powerbank via voltage conv.



Thoughts?
 
Back
Top