WILL BATTERY KICK IN IF WIRE IS UNPLUGGED outdoor cam 3rd gen!

hi All, wondering if anyone can help as I am looking to buy a spare battery pack for a wired outdoor cam gen 3. My outdoor cam unfortunately is in a position that can easily be reached to unplug the wire that connects it to a power socket (I live in a bungalow, UK, so roof height is somewhat reachable). My question is, if I placed a battery inside the camera and then used the wire to power the camera, if someone came along and unplugged the wire will the battery kick in and turn the camera back on? if so can someone tell me how to set this up or is it simply placing the battery in the camera and it automatically kicks in when wire is unplugged? thanks!