I'm still confused.

If you connect the battery to the camera will the camera start
consuming power immediately,

yes, the camera has no on/off, the battery is on a battery clip with a
lead that fits into the camera's power socket, so the camera consume
power once its all connected up. So, I need a timer switch in between
the battery and camera to make the connection active at a specific
time.


camera (or do something else) to make it start consuming power? Also,
once the camera starts consuming power from the battery


do you want it to continue until the battery is depleted, or what?

yes, i'm not bothered about the battery running down as it is
rechargeable