No real alarms. The green battery allows the machine to hold in it's memory "time stamps" of what and when something was done to the machine when the power is off.
Things it records: time and date when the main door was opened, same for cash box door, cash box removal, etc.
In that way the casinos could go back to their camera systems for those times and find out who was there. All of that type of data really is useless for the home owner, and we know the batteries leak and ruin hardware, that is why we recommend removing them. I do not agree with " keeping the machine as close to how it was in the casino" The machines are for enjoyment and in the end I would much rather have a functional machine the a non working one that you can say is "Just like it was in the casino " That's crap especially if you install a TITO system, those were never in the casinos either but if you want the "casino ticket in" feel you install them.
For me I want my machines functional for as long as possible and removal of that nasty green battery is the first thing a home user should do.