TTLock Battery Replacement Without Losing Your Settings

• A full matched set of new AA batteries, not a mix of old and new or different brands, since mismatched cells can cause voltage sag under load.
• Lithium AAs where the manual allows them. They hold voltage more consistently in the cold and generally last longer than alkaline, though some locks specify alkaline only — check your model's documentation.
• A small screwdriver if the battery cover is secured with screws rather than a simple clip or slide mechanism.
• The app open and the phone nearby to resync the clock after the swap.

1. Open the battery compartment, usually on the interior side of the lock, following your model's manual for the release mechanism.
2. Remove all old batteries at once and note their orientation before taking them out.
3. Insert the new matched set in the same orientation, checking each cell is seated firmly against its contacts.
4. Close the compartment and confirm the keypad lights up or the lock beeps to indicate power is restored.
5. Open the app near the lock and let it connect over Bluetooth. This resyncs the time, refreshes the reported battery level, and confirms settings are intact.
6. Test a passcode or fingerprint you already had set up to confirm nothing was lost in the swap.

A lock powered down for more than a few seconds — or one that has been running on weak batteries for a while — can lose track of the correct time. Since many time-limited passcodes and scheduled eKeys depend on the lock's own clock, a drifted clock can make a valid code appear to fail or a schedule fire at the wrong hour. Connecting the app over Bluetooth after a battery change typically resyncs the time automatically, so it is worth doing even when everything already seems to work.

Most locks warn well before they die — typically a keypad message, an app notification, or both once the level drops below a threshold. Many models also include an emergency power option, commonly a pair of exposed contacts on the outer keypad that accept a 9V battery to supply enough current for one unlock when the internal batteries are fully dead. Check your lock's manual for whether it has this feature and how to use it.

• Mixing old and new batteries. This causes uneven voltage and can trigger false low-battery warnings or erratic keypad behaviour.
• Ignoring the low-battery warning for too long. A lock that dies mid-operation can occasionally leave the bolt in an awkward position, making the swap more fiddly.
• Skipping the app resync. The lock still works locally without it, but the clock can drift and the app's reported battery percentage stays stale.
• Using rechargeable batteries not rated for the lock, since their lower voltage can shorten the runtime dramatically compared with the manufacturer's rating.