If the audible alarm is sounding, how many days will the battery last? I program this so that the alarm stays on even-if back in range, however will the battery last over a long weekend if alarming?

The battery should last long enough to get through a long weekend even in an alarm state however it is recommended that you download the logger and reset the alarm so that it’s not in a constant state of alarm.  The audible alarm doesn’t use an excessive amount battery power so as long as it’s not running for extended periods it should only have a minimal effect on the overall battery life.