Can you still use your home WiFi after a power outage? I tested it with a UPS and optical modem router, and the 14W three-piece set lasted four to five hours

last month, during transformer maintenance in the community, the entire building went dark at nine p.m. The first thing my mom said in the dark was, "Even without WiFi, my show is still on." I stared at the weak current box and remembered something I struggled with for half a year to figure out: the power outage is the power outage, not the internet . As long as you find a way to keep the optical modem and router powered on, there's a high chance the broadband at home won't be cut off at all. I will explain the tricks, timelines, and connections in between.

first settle this account: the power outage is the power cut off, not the internet

many people think a power outage equals a blackout, confusing the two as one. Broadband is the operator's fiber optic link, while WiFi is the wireless signal sent by your home router. If the router runs out of power, WiFi will naturally disappear, but the link on the other end of the fiber may not be cut off.

key is a little-known fact: fiber-optic line entering the home does not require a of watt-hour. From the operator's data center to your home, there's a splitter in between—the weak current shaft in the hallway or the small box in the optical interchange box that divides a single fiber into dozens of units. It's a passive device with no electronic components inside, relying solely on optical paths for splitting, and it works without power. There are only two real sources of power: the OLT equipment in the central office computer room and your home optical modem. The server room has backup power all year round, so when there's a power outage, it never gets to lie down.

so the accounts are easy to calculate: the mains power goes out, your fiber modem router runs out of feed and collapses, but the connection is still connected. One day, when you supply electricity to these two, the grid will come back.

But there is one exception that starts with cold water. Many old residential communities use FTTB fiber to the building —the fiber only reaches the hallway, where a device that uses mains electricity is hung in the hallway and connected by network cables to each household. When the hallway loses power, that device goes down, and whatever you plug in at home doesn't work—the whole building breaks down. The method to determine is simple: check whether the fiber cable you are entering is yellow or just a network cable plug. For those using the leather line to enter the home, congratulations, it's FTTH fiber to the door, and your own home decides; If the network cable is in the home, maintaining the network is not up to you. Please be patient when you call. My family uses a leather line to enter the household, so the lower accounts are counted.

what was lost during the three hours of the night at my house's WiFi

I actually have a 600VA UPS at home, which I installed when the NAS tripped last year ( wrote about whether to get UPS at the time). The optical modem, router, and NAS are all attached to it. Everything went on for 47 minutes of blackout, and I even felt a bit proud. At 47 minutes, the battery runs out and the whole family is completely black.

NAS there was nothing wrong over there. Before the power outage, it detected the battery was nearly dead and gracefully shut down according to the settings. This is exactly what a UPS is supposed to do. But the internet has also perished with it—phones are cutting data to the top, WeChat and Douyin are not affected, but the real pain is those dozens of smart devices.

the camera at the entrance was completely black, and I wanted to check if anyone had come or gone in during the power outage, but there was no footage; The speaker calls but there is no response; The vacuum cleaner is lying in its nest. The next day, I checked the app and saw that the blackout records from that time were all flashing with a blank space, the Mi Home device collective offline alert filled half the screen. After the call came in, it was even more exhausting: the optical modem registered, routers restarted, then dozens of devices queued to reconnect. The old 2.4G module devices were the slowest, and the cameras took about ten minutes to come online— these smart devices that only recognized 2.4G had slow connection was an old problem.

That night, I reviewed and came to a conclusion: NAS wants to "hold out until the power shuts down," while the network wants to "hold out until mains power returns." These two goals are completely different. Forcing a UPS just ends up with no one getting enough to eat.

Time Ledger: How long can a single battery hold up the network

understand the division of labor, you need to equip a small UPS separately for the network. Let's first calculate the power. The optical modem is rated at 15W, the router at 10W. Sounds scary, but I tested each metering socket one by one ( the electricity bill ): the modem is actually 6W, AX3000T router is 5W, 8-port switch is 3W, trio is 14W . The nominal price is the upper limit of the power adapter, not the actual power consumption; this account only counts based on actual measurements.

let's look at the battery. A backup 600VA small UPS costing over a hundred yuan contains a 12V 7Ah lead-acid battery, theoretically 84 watt-hours. With an inverter efficiency reduced to 20%, the actual output is about 67 watt-hours. 67 divided by 14 equals about 4.8 hours. I specifically chose an afternoon to pull off the grid for drills, holding out from 2:10 to 7:00 sharp, four hours and fifty minutes, which was to the accounts.

if you also install the same NAS, the N100 dual-drive read/write 26W comes in, and the load jumps straight to 40W, reducing the time to just over an hour—so my final setup is two separate UPS systems: the old NAS UPS handles data security, and if it shuts down gracefully, that's the mission; This newly purchased small UPS is dedicated to network protection. The 14W light load endures slowly, and regular maintenance and power outages simply can't handle it.

Hands-on Checklist: Which devices should be connected to the UPS and which should not

only three essential plug-ins: optical modem, main router, and switch. If you miss one thing, the link will be cut off—if the optical modem isn't plugged in, the broadband drops; if the router doesn't plug in WiFi, the switch won't be plugged in; if the switch isn't plugged in, those wired ports with the switch hanging on will be disconnected. If your home uses Mesh networking and the sub-router relies on wireless backhaul, you also need to plug in the sub-router; otherwise, if the main router is alive but the backhaul is disconnected, it's basically useless.

depends on the situation. For storage devices like NAS and surveillance hard drives and recorders, their UPS demand that data isn't online. The logic is the same as I wrote in my article about pairing a NAS with a UPS: just hold out until the safe shutdown, just one unit, don't compete with the network for battery.

clearly not plugged in: set-top boxes (you can't turn on your TV even if the power goes out), various charger desk lamps—feeding batteries to these devices that "have power but no output" is a pure waste of watt-hours. UPS output ports are already limited. I recommend plugging in the tag controller with the "optical modem" and "main router" so you won't get caught during the next maintenance. And there's another rule: never have an electric kettle or hair dryer on the UPS socket. 600VA can't handle it, but if it does, it will instantly drain your battery life.

Also, lead-acid batteries clearly degrade after two or three years. Try unplugging the mains power every six months to test real range. Just check the meter like I did—don't wait until the power outage is real to realize the battery is already tired.

without UPS's safety net, it's all legitimate roads

not every company is worth spending over a hundred on "blackout grid protection," claiming three guarantees as a safety net. First, mobile hotspots. Nowadays, data plans are generous, and turning on hotspots in half an hour after a power outage is more than enough. This is a zero-cost solution and the one that should be the default. Second, the 4G portable router. I used it for three months as broadband ( wrote about that experience ). Even during rush hour, it was more than enough for half an hour in emergencies, provided it fully charged itself.

third point is most easily overlooked: leaving a local backup route for cameras that go blind when the power goes out. My approach is to have the main camera at the entrance insert an SD card. Before the network and power are cut off, it can't record due to its last bit of inertia, but once the power is restored, it can resume recording on its own. Combined with the split-head of recording storage, I try to use the NVR local drive for important locations rather than pure cloud storage—during a power outage, the cloud path is cut off, but local storage recovers quickly. surveillance can't be seen in that article about remote links, and in the face of a power outage, everything is completely useless—don't count on it.

by the way, don't rush to turn off 5G on your phone during a power outage. Most base stations are still alive (the office server room has backup power), so data is used as needed. Power saving is enough by lowering brightness and locking the backend.

don't rush to get happy after the call comes in; do these three things in order

the moment mains power is restored, the device is actually at its most vulnerable. The voltage often fluctuates, and my sequence has always been three steps. Step one: Wait for the optical modem to register itself—letting the PON light flash slowly for a minute or two is a normal registration process. Don't be reckless and repeatedly unplug the power; every time the power goes out, the registration process starts over again (PON details have been covered in a special ). Step two: give the router and smart device ten minutes to reconnect. The 2.4G old devices are the slowest. If they're still gray after ten minutes, go to a single check—don't reset right away.

Step 3: Wait two minutes for the NAS to power on, and wait until the voltage stabilizes before proceeding; I casually checked the power strips of valuable equipment— the lessons of burning equipment during thunderstorms, as mentioned in the : the power surges and lightning are the same as lightning when a power comes in, and the few dozen yuan worth of good power strips are worth their value here.

the cost-performance ratio was unexpectedly high: over a hundred yuan, a 14-watt load, four to five hours of battery life, all in exchange for the reassurance of having a bit of "internet" at home on the night of a power outage. If your home also uses fiber optic cables, you can copy this matter as a homework.