The Power Is Out and Your Smart Lock Says Offline. Can You Still Get In?

The power goes out, or the internet drops, and you reach for your phone to check the front door — and the app says "offline." It is a genuinely alarming moment, and it usually arrives with two separate fears stacked on top of each other: that the door is now unlocked and you cannot see it, and that when you get home you will not be able to get in at all.

The good news is that the first fear is almost always misplaced, and the reason is simple enough to settle in one sentence. The bad news is that the second fear is real for a specific and surprisingly common set of households — and whether you are one of them is not a question about smart locks in general. It is a question about the exact model screwed to your door, and the answers differ so much between brands, and even between two product lines from the same brand, that nearly everything written about this topic online is wrong for somebody reading it.

We set up and untangle smart homes for households and small businesses across Southern California and the Coachella Valley, in an area that gets planned power shutoffs every fire season, so this comes up a lot. Here is the honest version, sourced to what the lock makers themselves publish.

The short answer: your lock is not on the grid

Almost every residential smart lock sold in the United States is battery-powered. It is not wired into your house current, it has no relationship with your electricity meter, and a blackout is not an event it can even detect. Schlage states it about as plainly as a manufacturer can: "Schlage Residential Electronic and Smart Locks are all battery-operated, so the lock will continue to function even during a power outage."

So during an outage the deadbolt still throws, the keypad still lights up, and the code you gave the dog walker still works. Your door did not silently unlock itself when the lights went out, and it did not silently lock you out either. What stopped is the part that reaches your phone.

Schlage draws that line too, in its documentation for the Encode Plus: "The Encode Plus is a battery-powered lock, ensuring that the keypad and app features continue to function even when there is a power outage," while "the lock's history and activity logs may experience delays in updates during internet disruptions. This information is stored in the Schlage cloud and requires a Wi-Fi connection to sync." That is the shape of it in general. Local access keeps working. The cloud-dependent conveniences — remote lock/unlock, notifications, the activity log, letting someone in while you are at work — are the part that goes dark, and they go dark because your internet went dark, not because anything happened to the lock.

What "offline" actually means here

When the app says offline, it is telling you that it could not reach the lock through the maker's servers. Between your phone and the deadbolt sits a chain of things that all need power and a working connection: your modem, your router, in many cases a separate bridge or hub, and the internet service itself. Every one of those runs on house current. The lock is the only battery-powered link in the chain, which is why it is the only one still standing.

That is worth internalising because it redirects all your effort. People spend outages worrying about the lock and resetting it, when the lock is the one component that is definitely fine. If you want the remote features to survive a power cut, the thing to fix is upstream — and we have written up that whole problem separately, because it turns out the network in the street is legally required to ride out three days while the equipment in your house typically lasts minutes. Our guide to keeping your internet working during an outage or PSPS covers what to put on battery backup and for how long.

And if your lock shows offline while the power is perfectly fine, that is a different problem with a different answer — usually a band-steering router, a hub that got unplugged, or a Wi-Fi network that was renamed. Our guide to smart-home devices that keep going offline walks through that one, including the case where a whole group of Matter devices disappears at once because of a single border router.

The real risk is not the outage. It is the batteries

Here is the thing to actually worry about, and it is almost never what people arrive worried about. A power cut does not threaten your access. Dead batteries in the lock do — and an outage can make dead batteries much more likely to catch you out, because during one you lose exactly the warning system that was supposed to tell you.

Smart locks do warn you, generously. Kwikset's documentation describes the lock beginning to show a low battery icon and play a low battery tone at 10% remaining, with a typical warning period of two to three weeks before the batteries are actually done. Schlage records low and critically-low battery events in the history log inside the Schlage Home app, and flashes a low-battery icon on the touchscreen after a code is entered. Under normal conditions you get plenty of notice.

But a chunk of that warning system is app-based and cloud-delivered — a notification on your phone, an entry in a history log that syncs over Wi-Fi. When the internet is down, those do not reach you. So the classic bad sequence is not "the power went out and the lock stopped." It is: the batteries were already low, the notification never arrived because the network was down, nobody looked at the keypad closely for a few days, and the lock finally died at the least convenient moment.

The battery mistake almost everyone makes for exactly the right reasons

This is the single most useful thing in this article, and it is counterintuitive enough that we see smart, careful people get it wrong constantly — usually while trying to be more prepared, not less.

When you decide you want your door lock to be reliable through outages and fire season, the natural move is to put the best batteries you can buy in it. Premium lithium AAs are the obvious choice: they last longer, they perform far better in cold, and they hold their voltage. Everything you know about batteries says this is the upgrade.

Schlage says not to. Its help centre states directly that "Schlage locks are not compatible with lithium batteries," and that "using lithium batteries can lead to battery drain issues and affect lock performance." What it asks for instead is unglamorous: four AA high-quality alkaline batteries for its smart locks, and a 9-volt high-quality alkaline battery for its keypad locks. Guidance in the same family applies to rechargeables, which Schlage's battery-change instructions steer away from on the grounds that they may not provide steady power.

The mechanism is worth understanding, because it explains why the upgrade backfires rather than simply being unnecessary. These locks decide how much charge is left by measuring voltage. An alkaline cell drains along a long, sloping curve, so the lock can watch the voltage sag and give you those weeks of warning. Lithium cells are prized for the opposite behaviour — they hold a near-flat voltage almost to the end and then fall off a cliff. A lock reading that flat line has no way to see the end coming, so you can lose the low-battery warning entirely and go from "fine" to "dead" with nothing in between. The premium battery does not make the lock more reliable; it removes the early-warning system you were relying on.

So: check your own manufacturer's stated battery type and follow it, even when a better battery is sitting right there on the shelf. This is one of the few pieces of tech advice where the cheap option is the correct one, and it is written down in the documentation almost nobody reads.

Your emergency way in is a per-model fact, and the differences are severe

Now the part that the rest of the internet flattens into a single confident paragraph, and should not. When the batteries in a smart lock are genuinely dead, how you get into your house depends entirely on which lock you own. There are three broad answers, they are mutually exclusive, and at least one brand ships all three across its own catalogue.

The first answer is a mechanical key. Most keyed smart locks retain a normal keyway, and if the batteries die you use it like any other deadbolt. Schlage's guidance for a dead Encode is exactly this: use the mechanical key to lock or unlock the door until the batteries are replaced.

The second answer is a 9V jump start. Some locks have a pair of exposed contacts on the outside of the unit; you hold a 9V battery against them, which powers the lock just long enough to type your code and get the bolt to retract. Kwikset documents this for its Obsidian model, which "has a set of 9V battery terminals underneath the touchscreen," with the procedure being to touch a 9V battery to the outside terminals and maintain contact, wait for the screen to light up, enter a valid user code, wait for the motor to retract the deadbolt, and then replace the batteries immediately once you are inside. Yale offers the same style of emergency terminal on its Assure Lock 2 range.

The third answer is that there is no answer, and this is the one that strands people. Yale sells its Assure Lock 2 in explicitly key-free versions — marketed on the strength of having no cylinder to pick, which is a genuine security advantage and also means there is no keyhole to fall back on. On a key-free lock, the 9V terminal is not a nice extra; it is the entire contingency plan. If you own one, a 9V battery in the glovebox is not optional preparedness, it is the difference between getting in and calling a locksmith.

Two locks from the same brand can behave completely differently

It would be convenient if these answers sorted neatly by manufacturer, so you could learn "Schlage does this, Kwikset does that" and be done. They do not, and assuming they do is how people end up on their own porch discovering a fact they should have learned in daylight.

Schlage is the cleanest illustration. Its help centre states that "the Schlage Encode series locks do not have a jumpstart feature like the Schlage Touch series," and spells out the contrast: "While the Touch series offers a 9V battery jumpstart option for emergency power, Schlage Encode locks rely solely on their internal AA batteries for operation." Two product lines, one brand, same shelf at the same store, opposite emergency behaviour. And note which way round it falls — the Encode is the more advanced, Wi-Fi-connected, more expensive lock, and it is the one with fewer ways in.

Kwikset splits internally too. The 9V terminals are documented for Obsidian; for its other models the published behaviour is simply that the lock stays in whatever state it was last in when the batteries run out, with no external emergency power method described.

The practical instruction that falls out of this is short. Do not reason from the brand, and do not reason from what you read about smart locks generally. Go and find out what your specific model does, once, while you are comfortable and indoors — search the manufacturer's own support site for your model number, which is usually printed on a label on the inside half of the lock or on the original box. Then act on the answer: hang the mechanical key somewhere real if you have one, or put a 9V battery somewhere you can reach without needing to be inside the house if you do not. Five minutes now, and the failure mode stops existing.

Where the key or the 9V should actually live

Having established what your backup is, the obvious follow-up is where to keep it, and there are a couple of traps. The backup key inside the house is not a backup. Neither is the 9V in the kitchen drawer, for exactly the same reason — both live on the wrong side of the door they are meant to open.

A lockbox mounted outside works, and it is what we most often suggest, but treat the code on it as seriously as you treat the lock's own code: a lockbox with the builder's default combination still on it is a decoration. A trusted neighbour is the low-tech option that has never once failed anybody. A car glovebox is reasonable for a 9V provided the car is not usually parked inside the garage you cannot open. And if you have a detached garage or a side gate, check whether the backup gets you through that too, or only through the front door.

One more, specific to the 9V approach: check the battery occasionally. A 9V that has sat in a hot glovebox through a Coachella Valley summer for three years may not have enough left in it to drive a motor, and the moment you need it is not the moment to find out.

A hub in the mix changes which half stops working

If your lock talks to a hub rather than straight to your Wi-Fi — most commonly a Z-Wave lock paired to a home hub, or a Matter lock running over Thread — then an outage splits your capabilities differently, and it is worth knowing which side of the split you are on.

The lock keeps working at the door regardless, because that is a battery and a keypad and nothing else. What depends on the hub is everything remote: app control, notifications, and any automation such as auto-locking at night. And here the hub becomes the fragile link precisely because, unlike the lock, it is plugged into the wall. When the power goes out, the lock is unbothered and the hub is dead, so the door works and the app does not.

That is a strong argument for putting the small box on a battery backup rather than fussing over the lock. It is also worth knowing which device in your house is doing this job, because it is often not the one you would guess — in a Thread setup the role belongs to a border router, which might be an Apple TV, a HomePod mini, a Nest Hub or an eero, and unplugging it to make room for a Christmas tree has taken down a whole floor of devices for more than one customer of ours. We cover finding yours in our smart-home offline guide.

One widely repeated rule about Wi-Fi bands is now out of date

While we are correcting things: if you go looking for why a Wi-Fi lock will not reconnect, you will be told everywhere and with total confidence that smart locks only work on 2.4GHz Wi-Fi and never on 5GHz. That was reliably true for years, it is still true for a great deal of hardware, and it is no longer true as a blanket rule.

Yale announced on October 23, 2025 that the Assure Lock 2, Assure Lock 2 Touch and Assure Lock 2 Plus with Wi-Fi modules support 5GHz networks, subject to running firmware version 1.0.32 and a current Yale Access app. The exclusions in that same announcement matter as much as the headline: locks that connect through a Yale Connect Bridge, and locks without Wi-Fi capability, do not get this — and Yale notes that not all its smart locks connect to Wi-Fi in the same way.

The reason to care is practical. If you own newer hardware, an installer or a forum post may talk you into rebuilding your home network around a separate 2.4GHz-only SSID that your lock does not actually need. If you own an older module or a bridge, the old rule still governs and the band question is still the first thing to check. Either way, the answer is a firmware-and-model question now, not a smart-locks-in-general question — which is the same lesson as the emergency-access one, and it is the reason this article keeps pointing you at your own model number instead of giving you a rule.

The Southern California version

Two things make this less theoretical here than it would be elsewhere. The first is that our outages are often scheduled. Public Safety Power Shutoffs during fire season mean the utilities frequently tell you in advance that the power is coming off, which converts this entire article from an emergency into a checklist you can work through the afternoon before: check the lock's battery level while the app can still tell you, make sure the backup key or 9V is outside the house, and put the router and any hub on a battery backup if the remote features matter to you.

The second is evacuation. In a fast-moving fire or debris-flow warning, the failure that hurts is not the deadbolt — it is being somewhere else and unable to see or change anything at home, or needing to let a neighbour, a family member or a fire inspector in while you are stuck outside the area. That capability is the cloud half, the half that dies with your internet connection. It is worth deciding in advance whether it matters enough to you to keep the network alive on battery, and worth knowing that a physical code shared with a trusted neighbour keeps working when every clever remote option does not. A lock code is one of the few things in a smart home that survives having no power, no internet and no phone signal.

The third, for the many people around here who run a short-term rental: an offline lock does not stop a guest's existing code from working, but it does stop you issuing a new one remotely. If your check-in process depends on generating a code on the day of arrival, that process has a single point of failure at your property's internet connection, and it is worth having a manually-set backup code that you can give out over the phone.

What to do this week, in order

Find your model number on the inside half of the lock and look up, on the manufacturer's own support site, exactly two things: what battery type it requires, and what your emergency access method is. Everything else follows from those answers.

Put the correct batteries in it — the type the maker specifies, not the best batteries in the shop. If the manual says alkaline, that is not a cost-saving suggestion, it is how the low-battery warning works.

Move the backup outside. A key in a properly-coded lockbox, or a 9V somewhere reachable without entering the house, and if the lock is key-free make sure everyone in the household knows that the 9V is the only way in.

Set a calendar reminder to change the lock batteries on a schedule rather than waiting for the warning, since the warning is the part that gets lost when the network is down. Once a year, or before fire season, is plenty for most households.

If the remote half matters to you, put the router and any hub or bridge on a battery backup — not the lock, which does not need one.

How we can help

To be clear about what we are: we are not locksmiths. We do not install, rekey, or drill door hardware, and if you are locked out right now the person you want is a locksmith, not us. What we do is the part of a smart lock that is actually a network device — the Wi-Fi, the hub, the bridge, and the power behind them.

That covers most of what goes wrong. We sort out locks that will not reconnect after a new router or a renamed network, band and channel problems that leave a lock at the far end of the house dropping off, hubs and border routers that turn out to be a single point of failure nobody had identified, and battery backup sized properly for the equipment that actually needs it. We will also just tell you, honestly, which of your smart-home gear is worth keeping alive through an outage and which is not — we do not sell locks, so there is nothing we are steering you toward.

If your smart lock has been dropping offline, or you want the front door and the network behind it to be genuinely ready for the next shutoff, tell us which lock you have and how it connects, and we can usually tell you where the weak point is before we come out. We work with homes and small businesses across Southern California and the Coachella Valley, onsite or remotely.