Loss of programming on power failure?

["walter" <someone@xxxxxxxxxxxx>]

I own a ADT Safewatch 3000 (Vista 20P). It is working fine.

What happens if I am gone for a few weeks, when the AC power is off and the
backup battery has lost its power, too.

Assuming that the AC will not be restored while I am absent, will the panel
lose all programming? That would be expensive to reset when I return!

What prevents the panel from losing programming?

Thanks for any insights.

Walter