Which feature is critical for ensuring that alarms are effective during a power failure?

Battery backup is essential for ensuring that alarms remain operational during a power failure because it provides an alternative power source when the primary electricity supply is disrupted. Without battery backup, alarms may become inoperative during a power outage, which could lead to significant security vulnerabilities. This feature allows alarms to continue to function and alert homeowners or security personnel to potential threats despite the loss of electrical power.

While visual indicators, network connectivity, and remote monitoring are valuable components of an alarm system, they do not directly address the need for continuous operation during power failures. Visual indicators can signal an issue, but if there is no power, the alarm might not be able to sound or send notifications. Network connectivity is essential for alarms that depend on internet access for alerts, but again, this relies on power to function. Remote monitoring can enhance response times and situational awareness, but without a reliable power source to keep the alarm system active, these benefits are moot. Hence, battery backup is the critical feature that ensures alarms can still operate that alarms are able to function when most needed.