Best AA Batteries for Smart Locks: What Schlage, August & Yale Say (2026)

If your smart lock seems to eat batteries, the obvious fix, rechargeables, is exactly what most lock makers tell you not to use. This guide sets out what Schlage, August, Yale and Kwikset say about batteries, with links to their own pages, then explains why, and how long a set should last.

We have not run battery tests on smart locks. Where this guide gives runtimes, they are the makers’ own figures or estimates worked out from battery capacity, and the math is shown.

What Each Lock Maker Says

Other brands have their own guidance. Check your lock’s manual or the maker’s support site before switching battery type.

Why Lock Makers Want Alkaline

The makers give two kinds of reason.

Capacity. Schlage says lithium and rechargeable batteries have reduced capacity. August says rechargeables have limited capacity.

Battery reporting. Kwikset says its lock software and app are optimized for the distinct way an alkaline battery discharges, so the battery percentage stays accurate and the low-battery warning arrives on time. Rechargeables have a flatter discharge curve, so the percentage may be wrong, and you might not get a correct warning when the batteries are nearly empty. Yale makes the same point more briefly: the correct battery type keeps its Battery Insights reporting accurate.

In practice:

• Alkaline starts at about 1.5V and its voltage falls steadily as it drains. A lock can read the charge left from the voltage.
• NiMH runs at a nominal 1.2V per cell (Battery University, BU-203). That is below a fresh alkaline, so a lock tuned for alkaline can read NiMH as part-drained from the start.
• A 1.5V lithium AA with a built-in regulator does the opposite. It holds about 1.5V for most of the charge, then drops to about 1V near empty, so the lock can read it as full almost to the end, and the low-battery warning may come late. On a door lock, a late warning is the one you least want.

Getting the Most From Alkalines

The makers’ own tips:

• Use name-brand alkalines. Schlage says to replace lithium or low-quality alkalines with name-brand alkalines if battery life is poor.
• Fix the door alignment. Kwikset says even slight misalignment between the door bolt and the strike plate adds friction and costs power. It calls this by far the most common cause of short battery life, and says to check it first.
• Strengthen the Wi-Fi. Schlage says a missing or weak Wi-Fi signal keeps the lock searching for the network, which drains the batteries.
• Watch the usage. Schlage says fewer than 10–15 lock and unlock cycles a day is acceptable. Heavier use drains faster.
• Avoid dual pairing. Schlage says pairing an Encode Plus with both the Schlage Home app and Apple HomeKit significantly increases battery use.
• Turn off extras. Kwikset suggests turning off lock sounds and the status LED in its app, and making sure the lock is firmly mounted.
• Clear the alert properly. After changing batteries in an August lock, operate it three times from the August app, over Bluetooth or remotely. August says operating it by hand will not stop the low-battery notifications.

How Long a Set Lasts

• Schlage Encode Series: Schlage gives 6 months as the expected battery life.
• August: The August app doesn’t show a battery level for its locks. It notifies you when the batteries reach 25% capacity, and sends daily emails and push notifications as they near the end.
• Yale (Yale Access app): Battery Insights reports one of four states (Sufficient, Low, Critically Low, or Check Battery Status / Unknown). When the batteries are Sufficient, it may also show an estimate of how long they will last, which improves as it learns how you use the lock.

If Your Lock Allows Lithium or Rechargeable AA (Estimated)

This section applies only if your lock’s manual does not exclude lithium or rechargeable AAs. It does not apply to the Schlage, August, Yale and Kwikset locks above.

Method. In the same lock, used the same way, runtime is roughly proportional to the energy stored in the set of batteries. So if you know how long one kind of set lasts, the estimate for another is:

estimated runtime = (energy of the new set ÷ energy of the set you know) × how long the set you know lasts

Taking disposable lithium as the set you know:

For example, if a set of Energizer Ultimate Lithium lasts your lock a given number of months, a set of SCIGOLD AA should last about 0.99 times that per charge, and a set of Eneloop Pro about 0.69 times that. These are estimates from capacity, not measurements. Energizer gives no mWh figure for its Ultimate Lithium AA: the constant-power chart in its L91 datasheet shows roughly 4,200 mWh at a 1 W draw and roughly 5,000 mWh at 0.1 W, and we use about 4,500 mWh. A lock draws little power most of the time, so disposable lithium may do somewhat better than this table shows. SCIGOLD’s capacity is SGS-measured (test summary); the other figures are manufacturer-reported.

Two cautions if you go this way:

• Don’t wait for the warning. A regulated 1.5V cell can read full for most of its charge. Note the install date and recharge the set a little before your estimate runs out.
• Charge and replace as a set. SCIGOLD AA cells have no charging port of their own. They charge in the 4-slot Pocket Case (CW505) or the 8-slot Home Case (CW508), which runs from one USB-C cable. A full charge takes about 2.5 hours from a 5V/3A source. Never mix old and new cells, or different chemistries, in one device.

Summary

Use the alkaline AAs your lock’s maker specifies. Schlage, August, Yale and Kwikset all say so, and all four advise against rechargeable batteries; Schlage and Yale also advise against lithium. Most short battery life comes from door alignment, weak Wi-Fi and heavy use rather than the battery brand, so fix those first.

SCIGOLD AA is for AA devices whose makers do not exclude rechargeable lithium AA cells. If your lock’s manual allows them, the estimate above shows what to expect. Otherwise, stick with alkaline.