Will Your Wi-Fi Work in a Power Outage? The Half That Fails Is the Half You Own

The wind picks up, the lights go out, and within about four seconds the house is silent in a way it never normally is. Then comes the second realisation: the Wi-Fi is gone too. No streaming, no cameras, no thermostat, no way to look up when the power is coming back — and if you work from home, no work.

The natural assumption is that the internet went down with the power, in the same way the lights did, and that there is nothing to be done about it until the utility fixes things. That assumption is wrong, and it is wrong in a useful direction. In most outages the internet did not go anywhere. The network in your street kept running. What stopped was a modem and a router sitting on a shelf in your house, drawing between them about as much electricity as a bedside lamp.

That distinction is the whole subject, because it changes the problem from "wait for the power company" — which you cannot do anything about — to "keep twenty watts alive," which is cheap, small and entirely within your control. What follows is what is already protected and by what rules, how much power you actually need, how long the various options really last, and which of them your own utility may help pay for.

The short answer, and why it is not the one you expect

Your home internet connection has two halves. There is the network outside — the fibre or coaxial cable in the street, the equipment on the poles and in the cabinets, the cable company's local node, the telephone company's central office. And there is the equipment inside, which is the modem or the fibre ONT, the router, and any mesh nodes scattered around the house.

The outside half is built and funded by a company whose entire business is being available, and it is engineered accordingly, with batteries and generators at the places that matter. The inside half is a couple of consumer boxes plugged into a wall socket in your hallway. When the grid drops, the outside half generally keeps going and the inside half dies instantly.

So the honest headline is this: in the majority of outages you did not lose your internet service. You lost the ability to reach it. Restore power to two small boxes and the connection is simply there again, at full speed, as though nothing happened.

California requires the network in the street to ride out three full days

The "your provider has backup power" claim gets made loosely all over the internet, usually by somebody about to sell you a battery. In California it is not a vague reassurance — for a large part of our service area it is a regulatory requirement with a number attached, and it is worth knowing the number.

The California Public Utilities Commission adopted Decision 21-02-029, issued on February 18, 2021, covering wireline communications providers — the companies that run the cable and fibre to your house. The decision directs those providers to have, in its own words, emergency backup power for a minimum of 72 hours in Tier 2 and Tier 3 High Fire Threat Districts, to support essential communications equipment and minimum service levels for the public immediately following an electric grid outage. It set a staged deadline: eight months from issuance for critical facilities and the facilities that support wireless networks, and eighteen months for all of their facilities in those tiers.

The companion decision, 20-07-011, imposes the equivalent 72-hour requirement on wireless providers, which is why cell sites in those areas are also built to keep running when the grid does not. Both requirements have been in force for years now.

The reasoning in the decision is the same one you are applying in your kitchen with a torch. The Commission wrote that the public expects to hear a dial tone, receive emergency alerts and notifications, and have access to critical information during an emergency — especially when the power is out — and noted that Californians now depend on those networks for distance learning, working from home and telehealth appointments. In other words, the regulator has already decided that internet access during an outage is not a luxury. It just could not regulate the two boxes in your hallway.

The catch: those rules stop at a line on a map

Here is the part that the confident "your ISP has backup power" sentence leaves out, and you should know it before you build a plan on top of it. The 72-hour requirement applies to facilities in Tier 2 and Tier 3 High Fire Threat Districts. It is a wildfire measure, not a general reliability guarantee, and it is drawn on a map.

That map matters locally, because our service area falls on both sides of it. Tier 2 marks an elevated risk of utility-related wildfire and Tier 3 an extreme one, and around here those tiers cover the canyons, foothills and backcountry — the ground above the Angeles National Forest, the hillsides, the inland and mountain communities — while a great deal of flat, dense, coastal suburbia is outside them entirely. If your house is on the flat, the equipment serving your street may well have excellent backup power, but it is not there because of this rule, and the duration is whatever your provider chose. The CPUC publishes the High Fire Threat District map as a public map viewer you can search by address, and it takes about a minute to find out which side of the line you are on.

The second caveat is written into the decision itself. Providers are allowed to identify facilities that do not need backup power, that cannot support it because of a safety risk, or where deploying it is, in the decision's phrasing, objectively impossible or infeasible — and to seek waivers on that basis. So the rule is a strong floor, not a promise about your specific street corner.

The practical takeaway is not to distrust it. It is to treat the outside network as probably fine and unknowable, and to put your money and attention on the half you can actually verify, which is the half plugged into your own wall.

Your entire internet connection runs on about as much power as a light bulb

This is the number that makes the whole problem tractable, and almost nobody knows it, because home internet equipment feels like it ought to be power-hungry and is not.

You can check yours in thirty seconds without buying anything. Find the power adapter for your modem or ONT and the one for your router, and read the small print on the brick. It will give an output in volts and amps — commonly something like 12V and 1A, or 12V and 2.5A on a larger router. Multiply the two and you get watts. A 12V 1A adapter is a 12-watt supply; a 12V 2.5A one is a 30-watt supply. Add your two or three devices together and, for a typical household, you land somewhere in the region of twenty to forty watts.

And that is the ceiling rather than the reality. Those ratings are what the adapter can deliver, not what the device habitually draws, so real consumption usually sits comfortably below the figure on the label. Either way, the scale is the point. Keeping your internet alive is not a generator-sized problem. It is a phone-charger-sized problem that people mistake for a generator-sized one, and that mistake is why they never solve it.

Why the runtime printed on the battery box is wildly pessimistic for you

A UPS — an uninterruptible power supply, a battery in a box that sits between the wall and your equipment — is the standard answer, and the reason people dismiss it is that the runtime figures look hopeless. They read "6 minutes" on the box and conclude it is pointless. Those figures are real, and they are also measuring something completely different from what you are about to ask it to do.

Take a concrete example. CyberPower's ST425 is a small, common, inexpensive unit, and its own datasheet rates it at 425 VA and 260 watts, with a runtime of 1.5 minutes at full load and 6 minutes at half load. Six minutes sounds useless. But look at what half load means on that unit: it means 130 watts. Manufacturers quote runtime at full and half load because that is how you compare units, and those loads assume you are running a desktop computer and a monitor.

Your modem and router are not a desktop and a monitor. At roughly twenty watts you are asking for well under a tenth of that unit's half load. Runtime does not scale in a neat straight line as the load falls — the inverter has its own overhead and batteries behave differently at low draw — but the direction is dramatic and consistent: drop the load by an order of magnitude and you move from minutes into hours. This is why the same battery that gives a gaming PC barely enough time to save a document will keep a router going through most of an evening.

Do not guess at the exact figure, though, because it depends on the model. Both CyberPower and APC publish runtime charts and online runtime calculators for their own units. Find your model, enter twenty or thirty watts instead of the default, and you will get a realistic number for the thing you actually want to power.

The one place it is genuinely fine to buy the cheap one

There is a well-known trap with inexpensive battery backups, and we have written about it elsewhere: budget units produce a stepped, approximated waveform rather than a true sine wave when they switch to battery, and a desktop computer with an active power factor correction supply — which is most decent modern ones — can read that approximation as a power failure and shut down the instant the battery takes over. It feels like a faulty UPS and it is not. If you are protecting a desktop, that is a real reason to spend more.

It is not a reason to spend more here. A modem, an ONT and a router do not have that kind of power supply. They run from small external adapters of the same family as a laptop charger, which are undemanding about waveform. The cheap simulated-sine-wave unit that would be a poor choice under your desk is a perfectly sensible choice behind the router.

That is a genuinely useful thing to know, because it is the difference between a fifty-dollar purchase and a two-hundred-dollar one, and nobody selling either of them has much incentive to tell you.

When a battery backup is not enough: the multi-day version

A UPS solves the common case — a flicker, a brownout, an outage of an hour or two — and it solves it completely and automatically, with no involvement from you. What it will not do is carry you through a planned shutoff that lasts a day or three, because a UPS battery is small by design. For that you want a portable power station, which is the same idea built around a much larger battery with normal wall sockets on the front.

The sizing arithmetic is unusually easy here, because power stations are sold by capacity in watt-hours, which is exactly watts multiplied by hours. If your gear draws twenty watts and you want twenty-four hours, you need about 480 watt-hours of usable capacity. Two days is roughly a thousand. Round up rather than down — conversion losses are real, batteries lose capacity as they age, and you will inevitably want to charge a laptop and a couple of phones from it as well, which is most of the point of owning one.

The pairing that works best is both, not either. Leave the UPS permanently in place so the short interruptions are handled without anyone noticing or doing anything, and keep the power station for the announced, long events, where you have hours of warning and can plug things in deliberately. A power station does you no good at all during the two-second dip that resets the router at nine in the evening, because nobody is standing next to it.

What to actually plug in, and the four mistakes we see

The first mistake is powering half the chain. Your connection needs every box between the wall socket and the wire in the street to be alive at once. On cable that is the modem and the router, which are sometimes one unit and sometimes two. On fibre it is the ONT — the box the fibre terminates on, often in a garage or a closet, sometimes a good distance from the router — plus the router. Keeping the router up while the ONT is dark achieves precisely nothing, and because the ONT is frequently out of sight in another room, this is the single most common way a well-intentioned setup fails on the day.

The second is mesh. If you have a mesh system, only the unit physically plugged into the battery survives; the satellite nodes in the back bedroom and the garage go dark with everything else. Your coverage during an outage collapses to whatever the main unit can reach on its own, which may not include the room you actually wanted to sit in. Worth testing before you need it, so the discovery happens on a calm Tuesday rather than in the dark. The same applies to any ceiling-mounted access points, and to network switches, which people forget are in the chain at all.

The third is forgetting that you also need something to use it on. A desktop computer is not going to run for hours on a small UPS, and a house full of working Wi-Fi with nothing to connect to it is a strange sort of victory. In an outage the useful devices are the ones with their own batteries — laptops and tablets — so charge them when the warning arrives, not when the power goes.

The fourth is what you should keep off the battery, and there is one item in particular that can destroy the UPS you bought to protect everything else. We cover that, along with the outlets people plug into by mistake, in our guide to what to do when the power comes back and the computer does not.

Your phone is the other half of the plan, with one honest caveat

The obvious fallback is your phone's hotspot, and it is a good one — it is already in your pocket, it costs nothing extra on most plans, and it will carry a laptop through email and a video call perfectly well. Because of Decision 20-07-011, cell sites in the Tier 2 and Tier 3 fire-threat areas are subject to the same 72-hour backup power requirement as the wireline network, so in exactly the places most likely to see a deliberate shutoff, the towers are built to stay up.

The caveat is capacity rather than power. In a widespread outage, everybody in the neighbourhood reaches for the same towers at the same time, and a cell site that is running perfectly can still be congested to the point of uselessness. Treat mobile data as your backup, not your plan, and where it matters most — a home office, a small business that takes card payments, a household with someone on monitored medical equipment — have both.

One practical note: your phone will drain much faster than usual while it is acting as a hotspot, so the power station that is charging your phone is doing more work for your connectivity than it appears to be.

The option your provider will sell you

Providers have started building this into the product, and it is worth knowing about because for some households it is genuinely the simplest answer. Spectrum, which serves a good deal of our area, launched Invincible WiFi in February 2026: a Wi-Fi 7 router with a 5G cellular connection embedded in it and a battery unit that keeps the router running for up to eight hours. If the cable connection fails it switches to cellular on its own, and if the power fails the battery carries it.

The appeal is that it is one box and there is nothing to remember, which for a household that will never test a UPS or think about watt-hours is a real advantage. The trade-offs are equally real: it is a recurring monthly charge on most plans rather than a one-off purchase, it ties your resilience to one provider, and the eight-hour battery does not cover a multi-day shutoff any better than a power station you own outright. Pricing varies by plan and changes, so check what it costs on yours rather than trusting a number in an article.

Our own honest position, and we sell none of this: if you have a genuine need for continuity and you are the sort of household that will not maintain equipment, the provider option is fine and you should take it. If you are willing to plug in a battery once and leave it there, buying your own is cheaper within the first year and keeps working if you ever change provider.

Your utility may pay for part of it

This is the piece that almost never appears in articles on this subject, and it is free money that a lot of eligible households never claim.

If San Diego Gas & Electric is your utility, the Generator Assistance Program pays a rebate of $150 on a qualifying portable power station and $300 on a qualifying fuel generator for 2026, with an additional $200 on generators or $50 on power stations for customers enrolled in CARE or FERA. The eligibility conditions are specific: you must be a current SDG&E electric customer, live in a High Fire Threat District Tier 2 or 3, and have already been through one or more Public Safety Power Shutoffs. It is limited to one of each per household, the purchase must be made in California in 2026, the power station has to appear on their published qualified product list, and applications must arrive within 60 days of purchase or by January 5, 2027, whichever comes first.

If Southern California Edison is your utility, there is an equivalent for customers in PSPS-affected areas: up to $200 on qualifying portable power stations — SCE's own description of them mentions keeping laptops, phones, tablets and your router running — and up to $800 on qualifying generators, claimed through the SCE Marketplace.

And a caution that matters a great deal around here, because plenty of local advice gets it wrong: Edison is not everybody's utility in Southern California. Pasadena, Glendale, Riverside and Anaheim run their own city-owned electric utilities, Los Angeles is on LADWP, and much of the Coachella Valley is served by the Imperial Irrigation District rather than Edison, on a boundary that does not follow city lines. Rebate programmes, outage alerts and shutoff notifications all come from whoever actually sends you the bill, so start with the name on the bill rather than assuming.

The Southern California version: you usually get a warning

What makes all of this more actionable here than in a place with ordinary storm outages is that a large share of our planned interruptions are Public Safety Power Shutoffs — power switched off deliberately when strong wind, low humidity and dry vegetation make the lines a fire risk. Unlike a blackout, they come with a published notification ladder that starts days ahead, and the restoration is slower than people expect because crews must inspect the lines before re-energising them. We have written up the notice timings and what to do with them in our guide to a computer that will not turn on after an outage.

The relevant point for your internet is what that warning is worth. Advance notice converts this from a hardware problem into a checklist. When the notification arrives, charge the laptops and the power station, confirm the modem or ONT and the router are on the battery-backed outlets rather than the surge-only ones, and check that the room you intend to work in is actually covered by the one mesh node that will still be alive.

The unannounced version is the summer one, and it is smaller and more frequent than people picture: on a hot afternoon at peak load it is the brief dip that resets the microwave clock, rather than a long blackout, that takes the internet away for five minutes while the modem renegotiates. Those dips are invisible to a plan built around power stations and completely absorbed by a UPS that lives permanently behind the router — which is the argument for having the cheap, boring, always-plugged-in option regardless of what else you own.

How we can help

For most homes this is a genuinely simple job you can do yourself in an afternoon: read the wattage off the two adapters, buy a small battery backup, put the modem or ONT and the router on the battery-backed outlets, and test it by pulling the plug on a day when it does not matter.

Where it gets less simple is when the chain is longer than two boxes — an ONT in the garage, a switch in a cupboard, ceiling access points, cameras that need to stay up, a gate or an alarm tied to the network — or when the outage has real consequences, as it does for a small business that cannot take payments or a household where somebody works from home without an alternative.

We look after computers, networks and small-business setups across Southern California and the Coachella Valley, and this is ordinary work for us: mapping which boxes actually have to stay alive, sizing the battery honestly for what you have rather than for what is on offer, wiring the network gear onto the protected side, and testing the whole thing under an outage so you find the surprises in advance. We do not sell hardware, so if the honest answer is a sixty-dollar battery from the shop down the road, that is what you will hear — and if you are on SDG&E or Edison in a shutoff area, we will point you at the rebate before you buy.