Why does my smoke alarm go off when I install a battery or turn on the AC power?

It is normal for smoke alarms to go off and sound briefly (up to 5-10 seconds) when you install a new battery or when they are powered up. If the alarm continues to go off and no smoke is present, the cause may be one of the following: 
• There may be insufficient battery power, try new batteries.
• Problems with voltage or insufficient electrical power (brown out) may cause a continuous weak sounding alarm. For AC or AC/DC models, temporarily disconnect power at the service panel until the brown out is over. If you do not restore the AC power, your smoke alarms cannot warn you of a fire.
• Incompatible warning device. If an incompatible alarm or auxiliary device is linked into a series of AC or AC/DC smoke alarms it may cause the system inadvertently go off.