If your premises is operating a battery-powered alarm system, a power outage is unlikely to affect your alarms. However, most businesses will have at least one fire alarm 'hardwired' to the mains. The extent to which your alarm operates in an outage depends on its health in the first place. If you keep up with a. Many fire alarm systems that are mains powered have two backup batteries to call upon in a blackout. The first is a backup battery in each external sounder – the type of alarm we often see. When a fire alarm rings during a power cut, it almost always means a battery is dead. Whether it's your kitchen fire alarm or at work, ringing smoke. After you've dismissed alerts and checked the backup batteries are working, your alarms should return to normal operation. Depending on your system, uncharged or faulty batteries can be. There is currently no law requirement for any commercial property to have a fire alarm system. However, the FSO does state that adequate fire safety equipment be used and this most.