Original post by: Vasilis Caravitis ,
If your camera draws 1A, this means that every hour it is on (with the engine shut off) it consumes 1AH (Ampere hour) from your battery. If your battery is e.g. 50AH and healthy, in 50 hours the camera will eat all its charge. However, the battery will loose its ability to start the motor much earlier, because the starter draws a very large current and a half-full battery will not be able to supply it. My advise: have an automobile electrician change the wiring, so that the lighter socket is switched off when the engine switch is switched off.