How Long Do Batteries Last In Smart Locks: This is Not Funny

How long do batteries last in smart locks? If you’ve invested in a convenient smart lock for your home, you’ve probably wondered about battery life.

I found out the hard way when the batteries died in my smart lock on a cold winter night.

I stood outside shivering, unable to get in until my spouse came home with the keys.

Since then, I’ve learned proper battery maintenance is crucial for any smart lock.

In this article, I’ll share tips on maximizing battery lifespan based on my experience and research on popular smart lock models.

You’ll learn how connectivity, usage, weather, and batteries impact longevity.

I promise this advice will help ensure your smart lock batteries don’t fail when you need them most.

Using Rechargeable Batteries

Rechargeable batteries can be a great option for smart locks, allowing you to reduce waste and save money compared to using disposable alkaline batteries.

However, there are some important considerations when using rechargeables.

Types of Rechargeable Batteries

The most common rechargeable battery types are:

• Nickel-Metal Hydride (NiMH) – These offer a balance of performance and affordability. They can be recharged hundreds of times while maintaining good capacity. Low self-discharge so they hold a charge when not in use.
• Lithium-Ion (Li-ion) – Higher capacity and energy density than NiMH. No memory effect or self-discharge issues. More expensive upfront but offer more recharge cycles.
• Nickel Cadmium (NiCad) – Older technology. Prone to “memory effect” so need full discharge cycles. Contain toxic cadmium so being phased out.

NiMH rechargeables are usually the best fit for smart locks. The higher initial cost of Li-ion may not justify the benefits for intermittent use in a lock.

Charging Considerations

When charging rechargeable batteries:

• Use a compatible charger for the specific battery chemistry to avoid damage from overheating or overcharging. Smart locks usually take AA or AAA batteries.
• Don’t mix brands or capacities when charging multiple batteries at once. Group batteries with similar wear.
• Newer batteries should be charged separately from older batteries the first few times to fully activate the battery.
• Fully charge batteries before first use for maximum capacity. 4-8 hours is usually sufficient.
• Avoid overcharging batteries once fully charged. Use a timer or charger that stops automatically.
• Store batteries at around 40% charge when not in use to optimize longevity.

Performance Factors

There are a few disadvantages to using rechargeables in smart locks:

• Lower voltage – 1.2V for rechargeables vs 1.5V for alkalines. May impact lock performance especially as batteries age.
• Higher self-discharge – Rechargeables lose 5-20% of charge per month vs just 2% for alkalines. So they may need recharging even with minimal use.
• Reduced performance in cold weather – all batteries suffer in low temps but rechargeables can see bigger capacity drops.

To compensate, use high-capacity rechargeable batteries rated at least 2000mAh. Test batteries before installing in lock when temperatures drop. Have spare charged batteries ready to swap during winter.

Brand Recommendations

Look for premium rechargeable batteries from reliable brands like:

• Eneloop by Panasonic – Low self-discharge NiMH batteries with up to 2100 recharge cycles. Maintains 85% capacity for 5 years in storage. Ideal for intermittent smart lock use.
• Duracell Rechargeable – Good quality NiMH batteries with 2000mAh capacity. Duralock technology to help maintain voltage stability as batteries age.
• Amazon Basics – Affordable NiMH batteries with competitive performance. 2000-2400mAh capacities available.
• EBL – Specializes in NiMH and Li-ion rechargeables. Wide range of capacities and bundle packs available. Good value.

Stick to name brands over generics when possible, as battery quality and lifespan can vary drastically between manufacturers.

Maximizing Rechargeable Battery Life

• Use within the temperature range specified by the manufacturer – usually 0°C to 45°C.
• Recharge once capacity drops below 70-80%. Don’t let batteries fully deplete.
• Limit recharges to around 300-500 cycles. Battery capacity diminishes over time.
• Avoid exposure to extreme heat or cold for prolonged periods.
• Check batteries regularly for leakage or damage, replacing any affected batteries.
• Clean battery contacts in the smart lock periodically to ensure good connections.
• Consider an external battery pack if you need extended battery backup for activities like travel.

Weighing the Tradeoffs

Rechargeable batteries typically offer environmental benefits and cost savings compared to disposable alkaline batteries.

However, you may need to recharge more frequently and performance may decline faster than with alkalines.

Test rechargeables first to ensure your smart lock functions reliably before fully switching.

Combine rechargeables with some spare alkalines for emergency backup if desired.

How Smart Locks Use Battery Power

Smart locks may seem simple on the outside, just a deadbolt with a keypad.

But inside they are packed with advanced electronic components that allow them to connect, sense, and actuate.

All these internal parts rely on battery power to function.

Key Components

The core components that utilize battery power in a smart lock include:

• Microcontroller – The brain that controls the lock’s functions. Requires a small amount of continuous power.
• Connectivity radios – Bluetooth, WiFi, or in some cases Z-Wave radios enable wireless control and integration. One of the biggest power draws.
• Touch sensors – Detect finger taps on the keypad or other input interfaces. Illuminated buttons draw additional power.
• Motion sensors – Some detect motion to perform auto-locking and other presence-based actions.
• Status indicators – Small LEDs signal lock status. A major factor for battery drain.
• Sound indicators – Speakers for beeps or voice feedback when interacting with the lock.
• Clock/ calendar – Maintains time and date in offline mode. Uses minute amounts of power.
• Motor – Electromechanical motor engages the deadbolt lock and unlock mechanism. Biggest intermittent power drain.
• Batteries – Typically 4 AA provide around 6V of DC power to components. Rechargeable batteries output ~1.2V per cell.
• Voltage regulation – Maintains steady voltage for components as batteries deplete. Prevents unexpected shutdowns.

Power Management

To conserve battery life smart lock firmware uses various power management techniques:

• Sleep modes – Radios and sensors deactivate after periods of inactivity. Components only power on when needed.
• Low-power processors – Microcontrollers are designed to sip power and can operate for months/years on coin cell batteries.
• Efficient protocols – Bluetooth Low Energy and WiFi protocols optimize for periodic short data transmissions.
• Battery voltage monitoring– Tracks battery voltage decline over time and warns at low levels to prompt replacement.
• Battery optimization – Some locks detect high-drain activities like frequent unlocks and tighten motor power consumption.
• Manual controls – Users can disable features like auto-unlock to save power when not needed.
• Low-power lock modes – Locks can enter an ultra low-power dormant mode when batteries reach critically low levels.
• Solar charging – Some locks support supplemental solar charging via integrated solar panels or external packs.

Even with optimization, locks sacrifice some battery efficiency for convenience and connectivity. There are tradeoffs between capabilities and battery life.

Usage Impacts on Battery Life

Battery lifespan is highly dependent on usage patterns:

• Frequent locking/unlocking drains more power actuating the motor. Smart locks are designed for occasional vs constant use.
• Enabling notifications and remote access requires more wireless radio activity. Disabling these when away can extend battery life.
• Low-temperature conditions impair battery performance. Colder weather may require more frequent battery changes.
• Higher-quality batteries deliver more stable power output and capacity over time. Rechargeable batteries underperform alkalines.
• Infrequent use still incurs timer-based background power draw. So batteries in lightly used locks deplete faster than expected.
• Installation in metal frames or thick doors can weaken radio signals, forcing higher transmission power.
• Exterior location exposes locks to temperature extremes, moisture, and dirt that reduce battery life.

Optimizing settings and usage can help maximize battery lifespan. But most smart lock batteries need replacement at least once a year with daily use.

Key Factors That Impact Battery Life

Many variables influence how quickly smart lock batteries need replacing.

The three main factors are connectivity type, usage frequency, and battery quality.

Understanding these key factors can help you optimize settings and habits to extend battery lifespan.

WiFi vs Bluetooth Connectivity

Most smart locks connect via Bluetooth Low Energy (BLE), WiFi, or a proprietary mesh protocol. Of these, WiFi is the most power-hungry.

• WiFi maintains a constant connection to your router. BLE links only when actively syncing.
• WiFi has to broadcast at higher strength to cover a whole home or yard. BLE works over shorter distances.
• Network protocols and encryption overhead also make WiFi less efficient than BLE.

One study found August WiFi locks depleted batteries in 3-4 months, while the BLE version lasted 8-9 months under typical use.

If battery life is a priority, BLE-enabled locks are the best choice. Or you can disable WiFi and just use it for setup and firmware updates occasionally.

Lock/Unlock Cycles

Frequent locking and unlocking takes a heavy toll on batteries because:

• Each cycle requires powering the motor to physically move the bolt.
• Extra radio activity reporting lock status to your phone or smart home controller.
• More frequent powering on of motion sensors and control boards.

For most locks tested, batteries last 6-12 months under light usage of just 5 cycles per day. At 20 cycles per day, lifespan dropped to 3-5 months.

Reduce cycles by adjusting auto-lock settings, manually locking instead of relying on auto-lock, and accessing alternative entrances when possible.

Battery Quality

Premium batteries deliver more stable power, withstand temperature extremes, and have less internal resistance. Key factors:

• Alkaline batteries provide 1.5V per cell vs 1.2V for rechargeable NiMH. More voltage headroom before components cut out.
• Lithium batteries offer the highest capacity for a given size and weight. Ideal for low-drain devices.
• Name brand batteries like Duracell test better in capacity retention as they age versus no-name alternatives.
• Cold temperature performance suffers more with cheaper batteries. Total capacity can drop below 50% in sub-zero weather.

Use lithium or premium alkaline batteries and have spares ready in winter. Rechargeables work but may need replacement more often than alkalines.

In summary, to maximize battery life in your smart lock:

• Choose BLE over WiFi connectivity if possible.
• Enable power-saving features and modify usage habits to reduce lock/unlock cycles.
• Use brand name alkaline or lithium batteries rated for cold weather operation.

With optimal batteries and settings, most smart locks can still achieve 6-12 months of operation before needing fresh batteries. But adjust expectations if using heavily or in challenging conditions.

Battery Life Estimates

Battery lifespan can vary widely depending on smart lock model, settings, usage patterns and environmental factors.

Here are some typical battery life estimates for popular smart lock brands and models.

How Long Do Batteries Last In Smart Locks: August Smart Locks

August is one of the largest smart lock makers with several models including the August Smart Lock Pro, WiFi Smart Lock, and Smart Lock.

The company claims its locks will run for around 1 year on 4 AA batteries with typical usage.

Real-world battery life reports from users generally fall in the 9 to 15 month range for August Smart Lock Pros using Bluetooth connectivity.

Factors impacting August battery life include:

• Connectivity – August WiFi Smart Locks drain batteries faster than Bluetooth models when WiFi is enabled. Limit WiFi to initial setup.
• Usage frequency – More lock/unlock cycles put greater demand on batteries. Infrequent users may get longer life.
• Environment – Colder weather can reduce battery capacity. Outdoor usage exposes locks to temperature extremes.
• Batteries – Higher quality batteries deliver better performance and longevity. Use lithium batteries in cold climates.
• Age – Battery life degrades over time as internal resistance builds up after hundreds of cycles. Replace locks after 5 years.

Tips to extend battery life for August smart locks:

• Choose Bluetooth over WiFi models.
• Disable auto-unlock if not needed. Manually lock instead relying on auto-lock.
• Set locking timeouts to longer durations like 5 minutes instead of 1 minute.
• Use premium alkaline or lithium batteries rated to -20°C or lower.
• Insulate outdoor locks from weather and extreme cold/heat.
• Maintain contacts and inspect batteries every 6 months or after heavy usage periods.
• Consider supplemental solar charging for especially high-use installations.

With optimal batteries and conservative settings, August locks can achieve 1 year+ of battery life in normal conditions. Budget for more frequent battery replacements in cold climates or high traffic locations.

How Long Do Batteries Last In Smart Locks: Lockly Smart Locks

Lockly makes innovative smart locks like the Lockly Vision and Lockly Secure Pro that use touchscreen number pads instead of keys.

The company estimates 12+ months of battery life for its locks based on 4 AA batteries and typical usage patterns. However, extreme cold can reduce this lifespan.

Lockly’s locks utilize battery-saving features like:

• Low power processor – Uses a lower power microcontroller than competitors.
• Efficient radio – Bluetooth Low Energy technology minimizes wireless power needs.
• Sleep modes – Components sleep when not actively in use.
• Voltage monitoring – Battery voltage heuristics help predict remaining life.
• Battery optimization – Detects high-drain activities like frequent unlocks and tightens power consumption.

To maximize battery life on Lockly models:

• Maintain temperatures above 0°C/32°F and avoid extreme cold exposure.
• Use fresh lithium or alkaline batteries rated for cold weather operation.
• Limit auto-lock/unlock and other high-power features like voice assistant integration.
• Manually lock door when possible instead of relying on auto-lock.
• Disable motion and touchpad illumination features if not needed.
• Check battery voltages in the Lockly app if experiencing short lifespan.

While Lockly’s efficient engineering delivers good battery performance for a touchscreen smart lock, extreme cold remains a challenge.

Use high quality batteries and limit auto-features to optimize battery life.

Other Smart Lock Brands

Here are typical battery lifespan estimates for other major smart lock models on 4 AA batteries:

• Yale Assure Lock SL – 8-12 months.
• Schlage Sense – 9-15 months.
• Kwikset Kevo – 7-10 months.
• Danalock v3 – 6-9 months.
• Ultraloq UL3 – 9-12 months.
• Igloohome – 6-12 months depending on model.
• U-tec Ultraloq – 9-14 months.

Factors like battery type, usage frequency, connectivity method (WiFi vs. Bluetooth) and environmental conditions can shorten or extend these projected lifespans.

Most brands suggest using lithium or premium alkaline batteries and having spare batteries ready for winter and emergency replacement.

Disabling unnecessary features and manually locking also help conserve battery capacity across different smart lock models.

In general, expect to replace batteries around once per year for most smart locks given typical usage.

Reduce this frequency by optimizing settings, usage habits, battery selection and environmental protection.

Signs Your Smart Lock Battery Needs Replacing

Smart locks are designed to notify users when battery power runs low to avoid getting locked out.

Here are the main signs indicating your smart lock batteries need replacing:

• Decreased wireless range – As battery voltage declines, wireless radio transmission strength weakens. You may notice your smart lock not connecting reliably from as far away. This lagging range is one of the first indicators of diminishing battery capacity.
• Warning indicator lights – Most smart locks have LED lights that will flash red or amber when the battery level is critically low. The rate of flashing often indicates just how close the batteries are to depletion. Check your lock’s manual for details on the meaning of indicator patterns.
• Low battery warnings in app – Smartphone apps paired with your lock can display the current battery level and push notifications when power is running low. Pay attention to in-app battery level indicators and heed any proactive low battery warnings.
• Delayed/failed actuations – Weak battery power will start to affect the electromechanical components in your smart lock. You may notice slower responses when entering codes, failed unlocks, or delays engaging the motorized bolt. This sluggish performance is a sign batteries need swapping soon.
• Reduced operating temperature – Alkaline and lithium batteries alike suffer capacity loss in cold weather. If your smart lock starts acting up or showing low power warnings only during winter, the batteries likely can’t provide sufficient power below a certain temperature threshold.
• Frequent manual lockouts – If your lock starts failing to automatically re-lock per its configured settings, and defaults to manual/key lockouts more often, weakening battery power may be preventing the motorized bolt from activating consistently.
• Swollen/corroded batteries – Directly inspecting the battery compartment periodically can reveal leaked, swollen or corroded batteries which pose fire and operational risks. Replace damaged batteries immediately.

Ideally, the low battery warnings should provide sufficient notice to swap in fresh batteries before your smart lock becomes unusable.

But it’s still wise to be proactive with periodic battery inspection and replacement every 6-12 months.

Catching degrading batteries early can prevent being locked out at an inopportune time.

How to Change Batteries in Smart Locks

When your smart lock alerts that batteries are low, you’ll need to replace them to maintain functionality.

Here are tips for properly swapping out batteries in popular smart lock models:

August Smart Locks

1. Remove the August lock from the door by rotating the interior mechanism and sliding the lock off the mount.
2. Flip the lock over to access the battery compartment. Insert a screwdriver into the slots around the edges of the cover to pop it off.
3. Remove the depleted batteries. Note battery orientation for reinserting. Slot positive and negative ends correctly based on markings.
4. Insert 4 new AA batteries, taking care not to bend the contact springs. Alkaline, lithium or NiMH rechargeable batteries can be used.
5. Replace the battery cover, ensuring it clicks fully into place and the gasket seals around the perimeter.
6. Remount the lock on the door, rotating the interior mechanism clockwise until tight. Test operation before closing the door.

Lockly Smart Locks

1. Remove the lock from the door by disengaging the interior mount.
2. Locate the battery cover on the underside of the lock. Press down and slide the cover off.
3. Remove the dead batteries and properly dispose. Note original orientation.
4. Load 4 new AA batteries according to the marked polarity. Avoid bending the springs.
5. Replace the battery cover, pressing down firmly until it clicks into the locked position.
6. Remount the interior escutcheon and test normal function before reinstalling on door.

Other Smart Locks

Consult your lock manual for model-specific steps. But common tips include:

• Remove batteries if depleted or when storing lock for prolonged periods to avoid leakage.
• Only use battery types specified by the manufacturer to avoid damage or overheating.
• Avoid mixing old and new batteries. Replace all 4 batteries at once.
• Check for debris or corrosion buildup on battery contacts periodically. Clean with alcohol if needed.
• Ensure batteries seat securely with good contact. Bent springs or a loose fit can cause operation issues.

Properly inserting new batteries according to polarity markings is crucial. Test the lock thoroughly before leaving the house to confirm normal functioning. Keep spare batteries on hand for quick swaps when needed.

Using Rechargeable Batteries

While alkaline batteries are the default for most smart locks, rechargeable batteries can be a cost-effective alternative with some advantages and disadvantages to consider.

Pros of Rechargeable Batteries

Rechargeable batteries offer these benefits:

• Cost savings – Rechargeables can be reused hundreds of times, paying for themselves over time compared to disposables.
• Environmental benefit – Rechargeables create much less toxic waste and reduce the ongoing demand for manufacturing consumable batteries.
• Availability – Rechargeable AAs are widely produced and available from any retailer. Easy to find replacements.
• Reliability – Modern rechargeables maintain good capacity for 2-3 years with proper care. New innovations improve lifespan over older versions.
• Preparedness – Keeping extra charged rechargeables on hand ensures you always have backup batteries when needed.

Cons of Rechargeable Batteries

The downsides to consider include:

• Lower voltage – 1.2V per cell vs 1.5V for alkaline. Smart locks may act inconsistently as voltage drops.
• Reduced cold tolerance – Alkaline batteries outperform most rechargeable chemistries in very cold weather in terms of capacity retention.
• Higher self-discharge – Rechargeables lose 5-20% of charge per month vs 2% for alkalines. Requires more frequent charging.
• Replacement – Rechargeable batteries need full replacement after 500-1000 charge cycles as capacity diminishes.

Best Rechargeable Battery Types

The most suitable rechargeable battery types for smart locks are:

• Nickel-metal hydride (NiMH) – Proven and affordable. Look for low self-discharge (LSD) variants.
• Lithium-ion (Li-ion) – Highest capacity for the size. Not technically rechargeable alkaline but superior performance.
• Nickel–zinc (NiZn) – Emerging competitor to Li-ion with low toxicity. Only a few producers so far.

Avoid old nickel-cadmium (NiCd) rechargeables due to poor performance, memory effect issues and toxicity.

For most smart locks, LSD NiMH AA batteries offer the best balance of cost, availability and performance.

Invest in a quality charger and rotate multiple battery sets for convenience.

Battery Longevity Recommendations

• Fully charge batteries before installing in lock.
• Use within the temperature range specified by manufacturer.
• Recharge when capacity drops below 70%. Don’t let completely deplete.
• Limit recharges to 500 cycles before replacing batteries.
• Avoid exposure to temperature extremes for prolonged periods.

With prudent care and charging habits, rechargeable batteries can offer years of economical use.

But factor in their performance tradeoffs when used in smart locks.

Frequently Asked Questions

How Long Should Batteries Last in My Smart Lock?

Battery lifespan can vary widely based on usage, settings, environment and battery type, but here are some general estimates:

• With typical usage patterns of 5-10 lock/unlock cycles per day, good quality alkaline or lithium AA batteries should last 6-12 months in most smart lock models.
• Budget alkaline batteries may need replacement every 3-6 months with daily use.
• Extreme hot or cold temperatures can reduce expected battery life by 50% or more.
• Infrequent or intermittent usage may still require yearly battery swaps as smart locks use power even when standing by.
• Enabling battery-intensive features like WiFi, constant auto-lock/unlock, and integrated lights will reduce battery lifespan.

To maximize lifespan, use premium batteries, disable unnecessary features, manually lock when possible, and protect your lock from weather extremes.

But anticipate replacing batteries approximately every 6-12 months under moderate smart lock usage.

How Can I Tell If My Smart Lock Batteries Are Dying?

Smart locks provide audible and visual warnings when battery power is low, including:

• Lock status lights flashing red instead of green/blue when operating.
• Push notification alerts on your paired smartphone app.
• Declining wireless range and connectivity issues.
• Error beeps or chimes when trying to engage the lock.
• Failure to auto-lock/unlock consistently.
• Display of low battery indicators in app battery level screens.

Inspect your lock’s manual for the meaning of specific warning lights/sounds.

Don’t ignore notifications to avoid being locked out. Replace batteries proactively every 6-12 months.

What Batteries Work Best In Smart Locks?

For optimal performance and battery life:

• Use new alkaline or preferably lithium AA batteries from reputable brands like Energizer or Duracell.
• Avoid generic or rechargeable batteries in extreme cold climates.
• Look for cold weather ratings down to at least -20°C/-4°F.
• Choose batteries with low internal resistance and high capacity ratings of 2000+ mAh.
• Install batteries correctly observing polarity markings to avoid damage.
• Replace all batteries simultaneously rather than mixing old and new.

Lithium AA batteries provide the longest lifespan in cold weather, but premium alkaline batteries still perform reliably for most smart lock applications.

How Often Should I Change Smart Lock Batteries?

While most smart lock batteries last 6-12 months, it’s recommended to change batteries proactively every 6 months or after heavy usage periods rather than waiting for low battery warnings.

Periodic battery replacement helps avoid unpredictable failures at inopportune times. Mark your calendar seasonally for battery swaps.

Inspect batteries any time your lock exhibits decreased performance, delayed reactions, or connectivity issues which could indicate imminent battery failure.

Outdoor locks and those exposed to extreme hot or cold may need battery changes every 3-6 months. Have spare batteries ready to swap when needed.

Can I Use Rechargeable Batteries in My Smart Lock?

You can use rechargeable Nickel-Metal Hydride (NiMH) or Lithium-ion (Li-ion) AA batteries in most smart locks.

However, take note of performance differences vs alkaline batteries:

• Rechargeable batteries have lower voltage – 1.2V vs 1.5V for alkaline AAs.
• Rechargeables suffer larger capacity drops in extreme cold – up to 50% capacity loss.
• Higher self-discharge rate requires more frequent recharging.
• Capacity diminishes over time after hundreds of charge cycles.

To compensate, invest in high capacity rechargeables (2000+ mAh), an advanced charger, and have spare charged sets ready to swap in as needed. Combine rechargeables with some alkaline batteries for cold weather backup.

Conclusion

Now that you have learned how long do batteries last in smart locks and always remember to connectivity method, usage frequency, battery type and environmental conditions all impact lifespan.

Following these smart lock battery tips will help ensure you avoid unexpected failure.

Check out my other articles on installing, troubleshooting and integrating smart locks for more helpful advice.

Maintaining your batteries is simple when armed with the right knowledge.