Replacement Batteries and Motion Sensor Outdoors?

I'm trying for the first time to set up my system.  It's been in a box for over two years.

It seems to be dead.  Nothing lit on the Base Station.   Guess the batteries are dead.   Any particular type of AA battery required?   Will generic Duracell AA work ?

Can a motion sensor be place on a outside wall?   Somewhat sheltered, but I live in Billings.  It does get cold and snowy here.

Thanks,

Clark711