Can you still get in if a smart lock's battery dies?

Short answer

Yes, with the locks we track: both have a keypad code and a physical backup key, and Eufy's S3 Max adds AAA batteries as emergency power.

Last checked Oct 21, 2026

Which products can do it?

Eufy S3 Max Video Smart LockYes
The S3 Max runs up to 5 months on two batteries, has 4 AAA backup batteries for outages, and also opens with a code or key.
Good to know: Battery life is Eufy's figure and depends on use.
LG Smart Deadbolt Lock (Apple Home Collection)Announced
LG's Apple Home lock comes with a keypad and a backup key.
Good to know: On sale from December 2026. Not yet reviewed.

Being locked out by a flat battery is the most common fear about switching to a smart lock.

How much warning each lock gives before its battery runs out.

How we know (3 sources)

Aug 25, 2025EFTMIndependent
Hands-on review of the Eufy S3 Max Video Smart Lock, which unlocks by reading the veins in your palm (up to 50 users), plus code or key, and doubles as a 2K video doorbell. The palm reader was touchy at first: you hover your hand for a few seconds, re-enrolling helped, and older users may struggle with holding a hand in mid-air.
Read the source
Oct 13, 2026TechliciousIndependent
Apple Home Collection, built by LG and Schneider Electric, goes on sale from December 2026, some items in early 2027. LG Smart Deadbolt ($349.95) unlocks via Ultra Wideband as you walk up with Home Key on iPhone or Apple Watch, has a keypad and backup key, works with Matter and locally without internet. Cameras $199.95-$399.95 (Video Doorbell Wired $249.95) recognize people, familiar faces, pets, vehicles and packages; recordings need iCloud+ ($0.99 for one camera, $2.99 for five, $9.99 unlimited), live view works without, and a HomePod, Apple TV or HomeView is required as hub.
Read the source
undated, read Oct 21, 2026EufyFrom the company
US product page for the FamiLock S3 Max, read Oct 22, 2026: $399.99; palm vein unlocking with the data stored on the lock; built-in 2K video doorbell; two batteries for up to 5 months of use plus 4 AAA backup batteries for power outages. Works with Matter, though camera streams aren't available over Matter.
Read the source

No status has changed since we started tracking. Every entry is dated and backed by the sources on this page.

Oct 21, 2026First recorded: Coming soon
LG Smart Deadbolt Lock (Apple Home Collection)
LG's Apple Home lock comes with a keypad and a backup key.
Oct 21, 2026First recorded: In stores
Eufy S3 Max Video Smart Lock
The S3 Max runs up to 5 months on two batteries, has 4 AAA backup batteries for outages, and also opens with a code or key.