A:AnswerI have not figured out how although I have not tried much. I am not so great at stuff like this . I might see if technical support is available.
A:AnswerFor this particular model, it appears to only have two handsets included. If you need more handsets, try ordering a different model which includes additional handsets or visit the manufacturer’s website and see if you can order from them directly.
A:AnswerIf the electricity goes out the battery in the handset should allow it to work. I'm not sure how long the battery lasts, I keep my phones on the battery most times when I am not using it.