What Kind of Batteries Do Smart Locks Use?

Smart locks offer keyless convenience, but unlike traditional locks, they rely on batteries to function. Choosing the right battery type is crucial for reliability, longevity, and avoiding unexpected lockouts.

This guide explores the most common battery types used in smart locks, their pros and cons, and best practices for maximizing battery life. Whether you’re a homeowner, landlord, or tech enthusiast, understanding smart lock power requirements will help you make informed decisions.

1. The Most Common Battery Types in Smart Locks

Most smart locks use standard, replaceable batteries rather than built-in rechargeable ones. This ensures users can easily swap them out when needed. The most common types include:

A. AA Batteries (Most Popular Choice)

• Why they’re used: Widely available, affordable, and long-lasting.
• Number of batteries: Typically 4 to 8 AA batteries, depending on the lock’s power needs.
• Expected lifespan: 6–12 months (varies based on usage and climate).
• Best for: Most residential smart locks due to balance of cost and performance.

B. AAA Batteries (Less Common but Still Used)

• Why they’re used: Smaller and lighter, ideal for compact smart lock designs.
• Number of batteries: Usually 4 AAA batteries.
• Expected lifespan: 4–8 months (shorter than AA due to lower capacity).
• Best for: Slim-profile smart locks where space is limited.

C. CR123A Lithium Batteries (High-Performance Option)

• Why they’re used: Longer lifespan and better performance in extreme temperatures.
• Number of batteries: Often just 1 or 2 needed.
• Expected lifespan: 1–2 years (ideal for low-maintenance setups).
• Best for: High-security smart locks or locations with harsh weather.

D. 9V Batteries (Rare but Used in Some Models)

• Why they’re used: Higher voltage for locks with stronger motors.
• Number of batteries: Usually just one.
• Expected lifespan: 6–12 months.
• Best for: Older or industrial-grade smart locks.

E. Rechargeable Battery Packs (Growing in Popularity)

• Why they’re used: Eco-friendly and cost-effective over time.
• Charging method: USB-C or proprietary charger.
• Expected lifespan: 3–6 months per charge.
• Best for: Tech-savvy users who prefer sustainability.

2. Factors Affecting Smart Lock Battery Life

Not all smart locks consume power the same way. Several factors influence how long batteries last:

A. Lock Mechanism Type

• Motorized deadbolts drain batteries faster due to mechanical movement.
• Latch-based locks are more energy-efficient.

B. Frequency of Use

• Locks in high-traffic homes (multiple daily unlocks) need more frequent battery changes.
• Vacation homes or rarely used doors may last over a year.

C. Wireless Connectivity

• Bluetooth-only locks consume less power.
• Wi-Fi-enabled locks drain batteries faster due to constant connectivity.

D. Temperature & Weather Conditions

• Cold climates reduce battery efficiency (lithium batteries perform better).
• Humid environments may cause corrosion if batteries aren’t sealed properly.

E. Smart Features & Alerts

• Locks with motion sensors, cameras, or voice control use more power.
• Frequent app notifications also contribute to faster drain.

3. Alkaline vs. Lithium Batteries: Which Is Better?

Most smart locks support both alkaline and lithium batteries, but they have key differences:

Recommendation: If you live in a cold area or want maximum reliability, lithium batteries are worth the extra cost.

4. How to Extend Smart Lock Battery Life

To minimize battery changes and avoid lockouts, follow these best practices:

A. Use High-Quality Batteries

• Avoid cheap, no-name brands (they leak more often and die faster).
• Recommended brands (without naming specifics): Look for reputable manufacturers with good reviews.

B. Enable Power-Saving Features

• Turn off unnecessary Wi-Fi or Bluetooth when not needed.
• Reduce auto-lock frequency if possible.

C. Regularly Check Battery Levels

• Most smart locks provide low-battery warnings (beeps, app alerts, LED flashes).
• Replace batteries before they completely die to avoid lockouts.

D. Keep Spare Batteries Nearby

• Store extras in a weatherproof container near the door (but not outside where thieves can find them).

E. Clean Battery Contacts

• Corrosion can disrupt power flow—wipe contacts with a dry cloth during battery changes.

5. What Happens When Smart Lock Batteries Die?

If your smart lock runs out of power, here’s what you can do:

A. Use the Physical Key Override

• Almost all smart locks have a hidden keyhole for emergencies.
• Pro tip: Keep a spare key with a trusted neighbor or in a secure lockbox.

B. External Power via USB (If Supported)

• Some locks have a USB-C or micro-USB port for emergency power.
• A portable power bank can temporarily revive the lock.

C. Call a Locksmith

• If no backup method works, a professional can help—but ensure they’re experienced with smart locks.

6. Rechargeable vs. Disposable: Which Is Better?

Best choice: If you prefer low-maintenance use, disposables are simpler. If you want eco-friendliness, rechargeables are better.

7. Future Trends in Smart Lock Battery Technology

As smart locks evolve, so do their power sources:

A. Solar-Powered Smart Locks

• Some newer models include small solar panels for self-charging.

B. Kinetic Energy Harvesting

• Experimental locks use motion energy (from turning the handle) to recharge.

C. Longer-Lasting Solid-State Batteries

• Emerging tech could extend battery life to 5+ years per charge.

Final Recommendations

For most users, AA lithium batteries offer the best balance of lifespan and reliability.
Check your lock’s manual for exact battery requirements.
Always have a backup key in case of battery failure.
Replace batteries proactively—don’t wait for a total shutdown.

By choosing the right batteries and maintaining your smart lock properly, you can enjoy keyless convenience without unexpected lockouts.

Conclusion

Smart locks rely on batteries, and the type you choose impacts performance, longevity, and reliability. AA and lithium batteries are the most common, with lithium being ideal for extreme climates. By understanding power needs and following best practices, you can ensure your smart lock remains functional for years.

Whether you prioritize cost, longevity, or eco-friendliness, there’s a battery solution that fits your needs. Stay powered, stay secure!