A:AnswerThere is no correct answer for time between charging. It depends on how active the area is and if it is night or day when recording, not sure but seems like night might use a little more power. I added mine on the regular Arlo system to see the difference and it is visibly better. It has a few hundred 10 to 15 second vids and still has 83% power.
A:AnswerI originally purchased the pro system with four cameras. I recently purchased the pro 2 camera as my fifth camera for that system and it works amazing.
A:AnswerNo Issues, I have dual pane windows myself and have 4 cameras on the outside the furthest one in on the opposite side of my garage from the back inside the house.
A:AnswerIf what you have is the Arlo Wire-Free camera model you may use the recommended rechargeable CR123 Tenergy battery detailed here : https://www.arlo.com/en-us/products/arlo/tenergy_rechargeable_battery_charger.aspx. ^RM
A:AnswerAs with anything that is connected to the internet it could be hacked but set strong passwords for router and connected devices and I think you will be fine.