Not necessarily. Many alarm systems are designed to trip when the mains supply is interrupted. The fact that the alarm was sounding indicates that there is life in the battery.

On my system the alarm also trips when the the mains re-connects and it is necessary to punch in the alarm code to re-set the system.

That being said, it is a sad fact that the re-chargeable gel cells which provide the back-up for most systems do eventually die and must be replaced. Again, depending on the system, the alarm panel may indicate when the battery needs replacing. Alternatively you can check the voltage as it should be fully charged when on standby.

If you are monitoring battery condition yourself, an annual check when you replace your smoke alarm batteries ( or other standby batteries ) is a good idea.

If a replacement is indicated you either need to change the battery or have your alarm company do this for you. As the alarm companies generally charge a small fortune for this service it is much cheaper if you can do it yourself. If you have a monitored alarm you may need to warn the alarm company in advance that you are servicing the system to save on the cost if the security have to pay a visit, or the grumbles if the constabulary have to attend!

Pero

Yes but sometimes the battery in the panel is duff but the SABU batteries are ok. So it goes off.