razer universal quick charging stand

Hi, I m interesting in buying the "razer universal quick charging stand" but I have a few question about the product that i dont seem to find the answer in the official site of razer so I wonder I anybody here can help me

1) Do you always need the stand connected to the wall, pc etc via the usb cabel for you controll to charge?
2) How long does the battery that comes with the product last(because all batterys dies sooner or later)?
3) What can you do when battery that comes with the product dies, can you by another battery from otherplace or do you need to buy another "razer universal quick charging stand"?