What Happens When Your Power Fails: Will the House Alarm Go Off if the Battery Dies?

Power failure is often a problem outside of your control. You can be going about your life, minding your own business and your whole town could suffer a power cut. For home security systems, this can be a worry. So what should you do when the power goes off? In this guide we’ll explain how power failures affect home security systems, and how batteries come into play.

Do home alarm systems work without power?

Wired alarm systems that run directly off of the mains power are designed to have a backup battery that kicks in during a power failure. This is designed to help in situations where your power fails, or someone directly tampers with your home’s power supply. Essentially this backup power source, usually in the form of a backup battery, is there to protect your home from tampering or during periods of power outage.

The Boundary hub connects directly to the mains power through a cable. This hub contains a backup power source in the form of a lithium backup battery that will last for 12 hours should the cable be cut or your power fails. This battery recharges too, and you’ll get an alert on your phone if your hub has switched from mains to back-up battery power.

In terms of wireless alarm sensors and outdoor sirens, things work a little differently. As each of these devices only requires a lithium battery, they aren’t reliant on mains power. This means there is no wire to cut and that they won’t fail if there is a power outage. It does mean, however, that they won’t function if the battery runs out.

Will my house alarm go off if the battery dies?

Your siren will not go off if the batteries run out. As batteries are your siren’s only source of power, it will not be able to function. However, you will receive a notification to the Boundary app on your phone telling you that the siren battery is low and alerting you when it is about to turn off. You’ll also be able to check battery levels at any time via the app. 

The same goes for other parts of your home alarm system. For the components that run purely on batteries, if those batteries are allowed to run out, that part of the system will not function. The parts of a Boundary system that run on batteries are:

Each of these comes with a LiPro battery that only needs replacing once every 12 months. You will receive a notification on your app when the battery is low.  Worth knowing as a guide if you’re wondering how often you should change your house alarm battery?

If one of your sensors goes offline, your outdoor siren will still sound, as long as it receives triggers from other sensors. Similarly, you’ll still receive notifications to your app if other sensors are live.

Why do alarms go off if there’s a power cut?

This is usually in place as a fail safe. Alarm systems are designed to see power failure as a problem and a trigger. This means some alarms sound during a power outage to advise that there’s an issue.

With a Boundary system, instead of the siren sounding, you’ll receive a notification on your phone that your alarm hub has switched over from mains to backup battery. Your outdoor siren will not sound if the battery fails, instead, you’ll receive an alert on your hub and phone.

How to turn off a house alarm during power cuts

This will vary, depending on the home alarm system you have installed. If your siren is hooked up directly to the mains, you will need to access your control panel to turn it off. This may mean you have to wait until the mains power is back, but if your hub has a backup battery you should be able to disable it with your PIN or passcode.

Always check the user guide for your specific security system though, as it may change. 

Do battery-powered sirens go off during a power cut?

A completely battery-powered system shouldn’t sound its siren simply because there’s a power cut. However, you will receive a notification to your app letting you know that the hub which controls the alarm system has switched to battery power. These alarm system backup batteries will then power your hub for up to 12 hours.

What to do after a power failure

If you’ve had a power cut you’ll need to make sure that your central hub is re-connected to the mains power supply before your battery backup dies. You’ve got a solid 12 hours to do this, which should hopefully be plenty of time as most power outages don’t last that long. 

In the case of batteries running out, you simply need to replace them. The Boundary home security system comes with its own app, and you’ll be able to see the status of all your batteries within the app. You’ll also be notified in plenty of time of a low battery, so you should be able to avoid battery failures before they happen.

Boundary offers a wireless security system that you can install yourself. There are a selection of different pay monthly security plans that are designed to bring you an affordable way to protect your home and family. Our Pro plan even includes a complimentary battery change every year. Another one less thing to worry about when it comes to maintaining a robust and reliable home security system. 

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