Motion detection operates from the front of the camera lens. The camera has to be on for it to work. Ideally, we recommend that it is connected to a power supply, such as a cigarette lighter or power bank.
Parking mode is directly connected to the G-Sensor and responds to shocks. The camera should not be switched on or connected to power in parking mode. This feature is currently only available for the Truecam A6, which can last for more than 24 hours in parking mode without external power.