Usually that indicates a low battery charge or bad battery. Make sure you do not have the battery backup side overloaded with too many devices. Do not plug inductive loads with motors or heating elements into the backup. Turn the device off and unplug anything that is plugged into the bachup. Plug the battery backup into the wall with nothing attached and turn on. Wait 10-15 minutes. this will charge the battery. If beeping continues after this with nothing attached, you likely need a new battery or the control/monitoring system is bad. If beeps stop, reinstall and do not attach more wattage than the unit can suppluy