I am shopping for an Uninterruptable Power Supply for a two-server web
app in my small office.  The app is a Windows ASP.NET 2.0 web app. 
The first server runs IIS 6 and the web app.  The second server runs a
MS SQL Server 2005 database used by the app.  Both servers are
co-located (and so could be plugged into the same UPS).

I know that I want to use an APC UPS product.

My question is about how to detect, from within a custom app (or
service) running on my web server, the following events:

1) That the servers have been switched to battery backup.
2) What the current estimated time left on battery power is.
3) How to initiate a shutdown of the database server from within the web server.

I need to do this so that this custom app or service can inform the
web app so that it, in turn, can notify remotely logged in users to
finish their work and log out and tell them how much time they have
left before shutdown.

APC has PowerChute software but I cannot find any detailed API
information about it online.  Also, I see that PowerChute comes in
different versions (Persons, Plus, Business, etc) and I don't know
whether I need one in particular to do what I want).  Or maybe I don't
need PowerChute and this is handled by the OS?  The OS for both
servers is Win Server 2003 Standard.