What Happens to Smart Locks When the Power Goes Out?  

Smart locks bring convenience and security to modern homes—until the power goes out. If you’re considering a smart lock or already own one, you might wonder: “Will I be locked out during a blackout?”

The good news? Most smart locks have backup power options. But not all work the same way.

In this guide, we’ll cover:
How different smart locks handle power loss
Battery life & emergency power options
Can you still lock/unlock your door manually?
Best smart locks for power outages
How to prepare for an outage

By the end, you’ll know exactly what to expect—and how to ensure you’re never locked out when the lights go off.

1. Do Smart Locks Work Without Power?

It depends on the type of smart lock:

Key Takeaways:

Most residential smart locks are battery-powered and keep working in outages.
Hardwired smart locks (common in businesses) may fail unless they have a backup.
Always check if your model has a manual key override—just in case.

2. How Long Do Smart Lock Batteries Last?

Smart lock batteries typically last:

• 6–12 months (standard AA batteries)
• 12–24 months (lithium CR123 batteries)

Factors that drain batteries faster:

• Frequent locking/unlocking
• Cold weather (reduces battery efficiency)
• Weak Wi-Fi signal (increases power usage)

Best Practices to Extend Battery Life:

1. Use lithium batteries (better performance in extreme temps).
2. Enable power-saving modes (if available).
3. Replace batteries proactively (don’t wait for a full drain).

3. Can You Manually Unlock a Smart Lock During an Outage?

Most smart locks have a manual override option:

Physical Key Backup

• Many smart locks include a keyhole for emergencies.
• Pro Tip: Keep a spare key in a secure place (not under the doormat!).

External Battery Packs (9V Boost)

• Some locks (like August Wi-Fi Smart Lock) let you tap a 9V battery to the keypad for a quick power boost.

Mechanical Override (Thumbturn Inside)

• If the smart lock is installed over a traditional deadbolt, you can turn the thumb latch manually from inside.

Warning: A few keyless smart locks rely entirely on batteries—if they die, you may need an external power source.

4. What About Wi-Fi & Hub-Dependent Locks?

• Wi-Fi smart locks still work locally in an outage—but you lose remote access until power/Wi-Fi returns.
• Z-Wave/Zigbee locks need their hub powered. If the hub loses electricity, remote control stops.

Solution: Use a UPS (Uninterruptible Power Supply) for your router and smart home hub if outages are common in your area.

5. How to Prepare for a Power Outage

1. Keep spare batteries (check your lock’s type—AA, CR123, etc.).
2. Store a physical key in a lockbox or with a trusted neighbor.
3. Use a UPS for Wi-Fi/hubs if you rely on remote access.
4. Enable low-battery alerts in the lock’s app.
5. Consider a solar-powered smart lock for off-grid homes.

6. Frequently Asked Questions

Q: Will a smart lock unlock automatically if power is restored?

No—it stays in its last state (locked/unlocked) unless you change it.

Q: Can I charge a smart lock with a power bank?

Some models support USB charging—check your manual.

Q: Do smart locks freeze in cold weather?

Extreme cold can drain batteries faster. Lithium batteries handle cold better than alkaline.

Final Verdict: Are Smart Locks Safe During Outages?

Most battery-powered smart locks keep working—just replace batteries yearly.
Always have a backup key or manual override option for emergencies.
Avoid fully keyless locks if you live in outage-prone areas.

Smart locks are still more reliable than traditional key locks in blackouts—as long as you prepare properly.