A:AnswerNo, this does not come with a unifying receiver. It is the nano receiver, which is designed to pair with one device. The unifying receiver will have an orange asterisk on it that indicates it can pair with more than one device. The M325 comes with a unifying receiver, but it is a smaller mouse.
This is NOT a bluetooth device, as another responder stated.
A:AnswerYes it does have a battery. Easy access, just turn it over, a picture of the battery is there with the direction on how you slide part of the base to get it off. I have bad hands and it was easy. Great mouse, had an older model for many years.