Should smart door locks connect to WiFi or use a gateway? If you use two locks for a year, the battery is three times worse, and you've covered all the pitfalls

last year, I replaced the smart lock on the entrance door. When choosing, I kept an eye on the fingerprint module and peephole, glanced at the network connection section, and immediately ordered the WiFi direct connection version. Four months later, the low battery alarm came in half the time I expected, and only then did I squat at the door to figure it out. It turns out there is more than one way to connect door locks to the internet, and the differences are so great that you have to tinker with the battery every few months.

first break down the three networking methods and explain them clearly

smart locks on the market, there are only three ways to connect them.

The first is WiFi direct connection : The lock has a built-in WiFi module, allowing you to connect to your home router, just like connecting to WiFi on your phone. The advantage is that no extra equipment is needed; once installed and connected to the internet, you can use it remotely. The downside is that WiFi modules are the most power-hungry of the three methods, and whether the lock can reliably connect to the network depends entirely on the WiFi signal at that location. By the way, locks with electronic peepholes and cameras consume more power, mostly requiring two sets of batteries and a lithium battery, with the camera part basically relying on charging to survive.

The second is Bluetooth plus gateway : The lock usually only uses Bluetooth to talk to a device at home, which should have a Bluetooth gateway function, such as my speaker Pro or a dedicated gateway costing just a few dozen yuan. The lock hands the message to the gateway, which then transmits it over the network to the phone. Bluetooth has low power consumption, and the battery is naturally durable.

The third option is Zigbee gateway : the route is the same as the second, except with a more power-saving protocol. There are plenty of devices that use Zigbee like bulbs, sockets, and sensors. I counted 49 smart devices in home and in that article, the gateway version's power-saving is systematic. But in the door lock category, Zigbee models are actually rare; Xiaomi's mainstream choice is Bluetooth.

First WiFi Direct Lock: Remote Connection Is Really Convenient, Battery Really Doesn't Disable

WiFi direct connection version is really enjoyable to use. When you're at the office, whoever opens the door at home immediately pops up the record; When my mother-in-law came to deliver something and I wasn't home, I sent her a temporary password remotely, sent it to her phone, and in two minutes she opened the door and left. In the first month, I praised this lock to perfection.

problem came at the end of the third month. The manual claims 8 months of battery life, while the Bluetooth version of the same model says 12 months. I accepted this price difference before buying. But what I didn't calculate was the location of my front door. The router is next to the TV cabinet in the living room, separated by a wall at the door plus a metal security door. Check the lock signal strength in the app, and it swings between -72 and -75dBm all year round. The weaker the signal, the more the WiFi module needs to repeatedly increase power and reconnect, which consumes much more power than normal standby and only makes things worse.

about four months and days later, the low battery alarm came. I wasn't satisfied. After replacing the battery, I took the lock off the door and hung it on a bookshelf two meters from the router. I ran for two days, and the battery drain visibly slowed down. The lock has no issues; the problem lies in the position. This is the deadlock of the WiFi direct connection version: you don't have the say where the lock is installed; the door locks exactly there.

switch to a Bluetooth gateway version, this account is settled

later switched to the Bluetooth version during a promotion, which is the current one. It only mentions Bluetooth to the speakers inside the door. The speakers are three meters from the door, so Bluetooth is very secure. The gateway is a freebie bought from home speakers, so not a penny was spent. Now, just over a year old, the battery still has about half a bar, and at this rate, it can last 14 months without issue.

Bluetooth version has a common misconception: before buying, you must understand this: Bluetooth version does not have a gateway, remote functionality is equivalent to no . The door opening record is only stored in the lock; the phone only syncs when the phone connects via Bluetooth at the door; Temporary passwords cannot be issued; When you're not home, you can't do anything. It becomes a "local fingerprint lock." So the correct way to buy a Bluetooth version is to first check if you have a device at home with a Bluetooth gateway. If not, include the cost of the gateway in the lock price and compare it together.

I've tried both methods for

remote experience, and honestly, there's not much difference. The Bluetooth version's door opening record is pushed two or three seconds slower, and that's about it. After all, the door lock message is just a few words, unlike cameras that stream video.

door lock installation is often the area with the worst signal in the entire house

after figuring this out, it became clear: the entrance door is the very edge corner of the layout, with the hallway outside, a metal security door in the middle, and some doors have a ring of metal trim on the inside. WiFi attenuation is much worse than ordinary brick walls when exposed to metal, with reflections and shielding. Yet the router is almost always on the TV cabinet in the living room, farthest from the door. The door lock is essentially placed in a blind spot of the family's WiFi.

so before installing a lock, don't skip a step: stand your phone on the inside of the door, at the height where the lock will be installed, and check the signal. You can install a WiFi test app on your phone to check the dBm level. If the drops below -70dBm, you have to find a way to . This threshold is recognized by both manufacturer customer service and locksmiths. At my home, the test was: living room -52, entryway -63, door lock position -72—basically following the line closely. You can figure out where the signal in the whole house is weak and where it's not. Just take a walk around your phone and you'll know the method. I wrote about this method in my article on Signal Blind Spot Self-Check locking the door lock is just right for this blind spot.

remedies are arranged by how much money is spent: zero-cost means moving the router toward the entryway; For just a few dozen yuan plus a signal amplifier, I once wrote a test whether an amplifier is worth buying. amplifier bandwidth is cut in half, but a door lock with a message load of just a few words is simply not enough; in fact, amplifiers are the best place to use them; If your budget allows, go for Mesh. Place the router on the entryway shoe cabinet, and the lock position can return to around -58. Placement is important—I've tested 8 points once and . Or simply choose Bluetooth or Zigbee, completely avoiding WiFi signal issues and placing the gateway wherever you want.

network setup and router replacement are two unavoidable hurdles

pitfalls in door lock network setup are similar to those of other smart devices. The top pitfall is still 2.4G: Router dual-band integration uses one name, so when you lock and configure the network, you might be assigned to the 5G band and fail immediately. I explained the reasons in my article on Robot Vacuum Robot Network Setup and the solution is the same: temporarily disconnect the dual-band and reconnect after finishing.

second hurdle is change WiFi name or router . Once the name is changed, the lock disappears, and the network must be re-connected. Being at home doesn't matter, it's just a matter of two minutes; When you're away on a business trip, the elderly at home guard a lock that says 'lost but doesn't affect the door opening,' which makes you feel uneasy. Even if the lock runs out of power or you lose contact, fingerprint unlocking doesn't affect the design. This is a guaranteed design, but remote recording is interrupted. The troubleshooting approach is the same as the offline Mijia device: first check the gateway or router, then check the lock end for reconnection.

door locks have their own temperament: if the grid fails several times, the lock will temporarily lock for a few minutes before trying again. This is a protection mechanism against tampering and violent attempts. The first time, I didn't know. After failing three times in a row, I kept pressing the reset port, but the more I pressed, the more it locked tighter. I waited eight minutes. Don't panic when it gets locked, and don't keep poking the needle holes—wait for it to unlock on its own before coming back.

buy which type of person to buy, and here's the order at the end

in the end, how do you choose? It depends on your three situations.

four steps in sequence: first test the signal at the entrance, speak with numbers; Then, based on the existing smart device ecosystem at home, the network is set accordingly. If you have many Mijia devices, use Bluetooth—no WiFi, so direct connection is the most convenient. Choose a daily setup where someone is home, and remove dual-band in advance for the 2.4G slot; If the battery drops after use, don't delay. Some locks have completely empty batteries and only recognize mechanical keys, leaving the key in a company drawer is awkward. During the few days when the battery was nearly depleted, the records would be sent intermittently, so don't think the lock is broken and you mess around.

a lock is normal for five or eight years, but the networking options section is worth a closer look than the peephole or fingerprint modules.