August Smart Lock Battery Draining Fast? 7 Fixes That Work

You put fresh batteries in your August Smart Lock a month ago — and the app is already flashing that low-battery warning. Again. A smart lock that eats batteries isn’t just annoying; it can leave you locked out at the worst possible moment.

Here’s the good news: an August lock draining batteries fast almost always has a fixable cause. August locks run on two CR123A lithium batteries (not AAs), and when something makes the motor work overtime or the radio stay awake, those batteries disappear in weeks instead of months. Work through these 7 fixes in order — most locks go back to normal battery life by Fix #4.

Fix #1: Put In Fresh, Name-Brand CR123A Lithium Batteries

This sounds obvious, but it’s the #1 real-world cause — and most people get the battery type wrong:

Your August Smart Lock takes two CR123A lithium batteries — not AA, not rechargeable. Rechargeable CR123As run at a lower voltage and die fast; alkalines can’t handle the lock’s power bursts.
Buy a name brand (Panasonic, Energizer, Duracell). Cheap no-name CR123As often arrive half-dead and drain in weeks.
Check the expiration date on the package — old stock loses charge sitting on the shelf.
When you swap them, clean the contacts with a dry cloth and make sure both batteries sit flat with the + ends facing the right way (marked inside the compartment).

If the last “fast drain” started right after a battery swap, bad or wrong batteries were almost certainly the cause. Start every troubleshooting round with a known-good fresh pair.

Fix #2: Check Your WiFi Signal — a Struggling Radio Drains Batteries

The August WiFi Smart Lock stays connected to your home WiFi, and a weak signal forces its radio to work much harder — retransmitting, reconnecting, staying awake:

Open the August app → select your lock → check the WiFi signal indicator. If it shows weak signal, the lock is burning battery just trying to stay online.
Front doors are WiFi dead zones — brick, metal doors, and distance from the router all kill signal. Move your router closer to the door side of the house, or add a WiFi extender halfway between.
Make sure the lock is on your 2.4GHz network, not 5GHz — 2.4GHz reaches farther and the lock holds the connection with less effort.
If your router recently changed or rebooted, the lock may be stuck in a reconnect loop — that’s Fix #5.

Our Ring doorbell battery guide covers the same weak-signal battery drain pattern — the physics are identical even though the device is different.

Fix #3: Recalibrate DoorSense — a Confused Sensor Wakes the Lock Constantly

DoorSense is the little sensor that tells your lock whether the door is open or closed. When it’s miscalibrated, the lock can’t tell the door’s state — so it stays awake, re-checks, and sometimes auto-locks and unlocks repeatedly:

In the August app → lock settings → DoorSense → run calibration again from scratch.
Make sure the DoorSense sensor (the small round piece on the door frame) is still firmly stuck in place — if it fell off or shifted, calibration is meaningless.
After recalibrating, watch the app for a day: the door open/closed status should update correctly every time.

A lock that auto-locks, immediately unlocks, and locks again is the classic DoorSense failure — and every one of those motor cycles costs battery.

Fix #4: Check Your Door Alignment — a Straining Motor Is a Battery Killer

This is the most overlooked cause. Your deadbolt has to slide smoothly into the strike plate. If the door sags, swells with humidity, or the strike plate shifted:

The lock’s motor strains and retries every lock/unlock — each failed attempt burns far more power than a clean cycle.
Listen closely when it locks: grinding, buzzing, or multiple attempts mean the bolt is fighting the frame.
Test it manually: turn the thumb turn by hand. If it feels stiff or catches, the door needs adjustment — tighten hinge screws, or slightly file/adjust the strike plate.

Fix the alignment and many “battery drain” complaints vanish overnight, because the motor finally does one clean cycle per lock.

Fix #5: Tame Auto-Unlock and Activity Frequency

Convenience features cost battery. Audit what your lock is actually doing all day:

Auto-Unlock: if you walk past your home frequently (or your geofence is huge), the lock wakes up and prepares to unlock dozens of times a day. Shrink the geofence radius in the app, or turn Auto-Unlock off if you don’t use it.
Auto-Lock timer: a very short timer means constant motor cycles. A 5–10 minute delay is the sweet spot for most households.
Activity feed: every lock/unlock syncs to the cloud. You can’t disable logging, but reducing unnecessary cycles (above) cuts the syncing too.
Turn off notifications you don’t read — each push keeps the phone app polling, which keeps the lock’s Bluetooth radio busier.

Fix #6: Update Firmware and the August App

August regularly ships firmware that improves power management — running old firmware can mean running old, hungrier code:

Update the August app from your phone’s app store first.
In the app → lock settings → check for a firmware update and install it (stay near the lock with your phone during the update).
After updating, restart the lock: remove one battery for 10 seconds, reinsert it, and let the lock reboot.

If the drain started right after a firmware update, this step matters most — updates occasionally reset calibration or settings, so re-run DoorSense calibration (Fix #3) after any firmware change.

Fix #7: Factory Reset, Then Check for a Dying Lock

If fresh batteries still vanish in weeks after all of the above, reset and rule out hardware:

In the August app: remove the lock from your account.
Factory reset the lock (hold the reset button per your model’s manual — on most August locks it’s the small button on the back, held until the lock beeps/flashes).
Set it up fresh — new batteries, fresh DoorSense calibration, clean WiFi join.
If the drain persists on a reset lock with aligned door and strong WiFi, the lock’s power circuitry may be failing — contact August support through the app. If it’s under warranty, this is a replacement conversation.

Frequently Asked Questions

How long should August Smart Lock batteries last?

With normal use, a pair of quality CR123A lithium batteries lasts 3 to 6 months. Heavy use (many daily lock cycles, weak WiFi, cold weather) pushes that toward 3 months. If you’re replacing batteries every few weeks, something in the fixes above is wrong — that’s not normal.

Can I use rechargeable batteries in my August lock?

It’s not recommended. Rechargeable CR123A batteries suffer voltage sag under load and inconsistent capacity. August officially recommends non-rechargeable lithium CR123A batteries. Rechargeables are the #1 cause of “I just changed them and they’re dead already.”

Why does cold weather kill my smart lock battery?

Lithium handles cold better than alkaline, but extreme cold still slows the chemical reaction — voltage drops, the lock thinks batteries are dead, and the motor needs more current to turn stiff, cold metal parts. If your door faces brutal winter wind, expect 20–30% shorter battery life in January and February.

Does the August WiFi bridge drain the lock battery faster?

The built-in WiFi on the WiFi Smart Lock uses more power than the Bluetooth-only models paired with a separate bridge — that’s the price of direct WiFi. If battery life is your top priority and you have the Bluetooth model, using the August Connect bridge plugged into a wall outlet (instead of the lock’s own WiFi) actually saves lock battery, because the bridge handles the power-hungry WiFi work.

The Bottom Line

An August Smart Lock chewing through batteries is telling you something is making it work too hard — wrong or cheap batteries, a weak WiFi signal keeping the radio awake, a miscalibrated DoorSense sensor, or a misaligned door straining the motor. Start with fresh name-brand CR123A lithiums, check your signal and alignment, and recalibrate DoorSense. Do those four and the vast majority of battery-drain complaints disappear for good.