What Happens to Your Security System During a Power Outage?

Power outages expose the most overlooked gap in home security: most systems have components that stop working when the electricity goes out, and most homeowners don't find out until it actually happens. This guide explains exactly what keeps working, what fails, and how to protect against it.

Direct answer: A properly configured professionally monitored system continues operating during a power outage via battery backup (typically 24 hours) and cellular backup. Standard Wi-Fi cameras stop streaming. Smart locks continue operating on their own batteries. The weakest link is internet-dependent alarm communication — cellular backup eliminates it.

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What still works during a power outage

✓ Base station / control panel

Runs on built-in rechargeable battery. Most systems provide 4–24 hours of backup. Vivint, SimpliSafe, and ADT all provide ~24 hours.

✓ Door and window sensors

Wireless sensors run on their own batteries (3–5 years). They are completely independent of your home's electrical system.

✓ Siren / alarm output

The alarm siren is powered by the base station battery — it continues operating during an outage.

✓ Cellular alarm communication

Systems with 4G LTE cellular backup continue contacting the monitoring center over cellular networks, independent of your internet.

✓ Smart locks

Most smart locks use AA/AAA batteries and operate independently of home power. Manual key backup works always.

✓ Battery-powered cameras

Wire-free cameras (Arlo Pro 5, Ring Stick Up Cam battery) run on rechargeable batteries and continue recording independently.

What stops working during a power outage

✗ Wired/PoE cameras (without UPS)

Cameras powered via AC outlet or PoE switch lose power immediately unless the switch is on a UPS battery backup.

✗ Live camera streaming

Even battery-powered cameras need Wi-Fi to stream live video. If your router loses power, streaming stops (unless your router has UPS).

✗ Broadband alarm communication

Systems that rely on broadband internet (no cellular backup) lose alarm communication when the router dies.

✗ Smart home automations

Hub-dependent automations (auto-lock on arm, smart light control) may not trigger if the hub loses power — even if individual devices have battery backup.

Battery backup vs cellular backup: how they're different

These are two separate and complementary protections that address different failure modes:

Backup type	What it protects against	How it works	Duration
Battery backup	Power outage (no electricity)	Base station runs on internal rechargeable battery	4–24 hours
Cellular backup	Internet outage (broadband down)	Alarm signals route over 4G LTE cellular network	As long as cellular coverage exists
Both combined	Power + internet outage simultaneously	Battery keeps system on; cellular keeps monitoring connected	24 hours (battery-limited)

The ideal setup has both. A power outage takes out your router (losing broadband), so without cellular backup you also lose alarm communication — even though the base station is still on battery. Systems with both protections (Vivint, SimpliSafe Fast Protect, ADT) remain fully monitored during most outage scenarios.

Best systems for outage resilience

Vivint

Most resilient during outages

Vivint includes 24-hour battery backup in the base station, 4G LTE cellular backup (included, not an add-on), and battery-powered outdoor cameras that continue recording during internet outages. The Vivint system remains fully monitored during simultaneous power + internet failures.

Best for: Storm-prone areas, rural properties with unreliable internet, premium buyers · Not for: Budget buyers — Vivint starts at $29.99/month

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SimpliSafe

Best DIY option for outage resilience

SimpliSafe's base station provides 24-hour backup. Cellular backup is included starting at the $24.99/month Interactive plan. SimpliSafe's sensors are all battery-powered. The combination provides professional monitoring continuity through most power outage scenarios.

Best for: DIY buyers who want outage resilience, no-contract preference · Not for: Standard plan ($19.99/mo) — cellular backup requires the $24.99/mo tier

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Frequently asked questions

What happens to my security system when the power goes out? +

Most professionally monitored systems switch to battery backup automatically. The base station or control panel continues operating for 4–24 hours depending on the system. Sensors and the alarm siren continue to function. However, Wi-Fi-dependent cameras stop streaming until power is restored.

How long does a home security system's battery backup last? +

Most home security system base stations provide 24 hours of backup on battery. SimpliSafe and ADT both provide approximately 24 hours. Vivint provides up to 24 hours of backup. Individual sensor batteries are independent and last 3–5 years.

Do security cameras work during a power outage? +

Standard Wi-Fi cameras stop streaming and recording during a power outage because they lose both power and internet connectivity. Cameras powered by PoE (Power over Ethernet) connected to a UPS (Uninterruptible Power Supply) can continue recording locally. Battery-powered cameras (Arlo, Ring Stick Up Cam) continue operating on their own batteries.

Will my alarm still contact the monitoring center if my internet is down? +

Only if your system has cellular backup. Systems with 4G LTE cellular backup (Vivint, SimpliSafe at $24.99+/mo, ADT) can communicate with the monitoring center even when your broadband internet is completely down. Without cellular backup, an internet outage cuts off alarm communication.

Does a smart lock stop working during a power outage? +

Most smart locks retain their battery power independently of your home's electrical system — they continue working during power outages. The lock mechanism itself uses AA or AAA batteries. However, if the lock is integrated with a smart home hub that loses power, automations (like auto-lock on arm) may not trigger until power is restored.

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