Hi guys! Bit of a question regarding security systems. Could you conceivably have a security system of multiple cameras, mag locks on doors and buzzer entry systems that could go down if the electricity was shut off but have only one main camera with a battery backup? Situation is in a building where only the main entrance is on a mag-lock which (I'm assuming) when the power goes down the mag lock disengages to allow easy exit in the event of a fire/emergency. But would it be possible that only one camera - lets say the one by the main entrance - also has a stand-alone battery backup. I could say that the system was being renewed section by section which is why only one camera is on a battery backup??