This is the inflator:

http://www.sears.com/shc/s/p_10153_1...ess+inflat or

I've never run out the battery, but I'm usually raising somewhat-
inflated tires up to pressure instead of starting from 0.

You can get refurbished from Amazon (where I got it) or from
cpoportercable.com. They may have run out. I paid $100 for my
refurb.

They are both loud. This is, of course, subjective, but I don't think
anyone would not think of them as loud. The PC is louder than the
tire inflator, but I've gotten to the point where I won't run either
without hearing protection. My younger ears didn't mind the sound
level when they were young.