The blackout that takes your Wi-Fi with it: why the phone stays up and the router drops

Every generator plan has the same hole in it: the house has power again and the internet does not, because the fibre's little white box (the ONT) or the 4G router is the appliance nobody counts as a load. The phone keeps working because its battery is inside it; your connection keeps working only if you give it the same courtesy.

The two-box problem

A wired connection is a chain with two powered links: the carrier's box (ONT or mobile router) and your Wi-Fi router. A blackout drops whichever one sits behind the meter you switched off, and most homes lose both while the mast outside the house keeps running on its own backup. So the fix is a list of watts, not a brand: a typical ONT is a few watts, a mid-size router on its own charger a handful more - double digits total, which puts a whole night of connectivity in the range of a good power bank, and the desk's power-bank article covers the conversion maths (the Wh number is the fuel tank, the watts are the thirst, divide for hours).

The bridge, three ways, in money order

• The cable-swap trick: most small carrier boxes accept 5V USB power or a DC barrel that an adapter cable pretends is a USB wall - a power bank through the right adapter runs the box through the outage, zero new hardware if you already own the brick.
• The mini-UPS: the small "router UPS" class of device - a battery dongle inline with the existing barrel plug - exists exactly for this job: it keeps the link alive through a short outage and, on the long ones, buys hours while the genset is what runs the rest of the house. Check the output voltage list before buying - 5V/9V/12V selectable covers the boxes; a fixed 12V on a 5V-only ONT is a paperweight.
• Inverter-loop it: if the house has an inverter, the router's and ONT's chargers go on the inverter circuit - which they already were on some installs, which is why the house has power and no internet: the switchboard's ring main forgot the one desk on the wall. The electrician's five minutes is the cheapest permanent fix on this list.

The boot order that saves a minute every time

Power back is not the end: a router that boots before the carrier link is stable spends its first minute in a retry loop, and the fibre's handshake is slower than both. The order is: carrier box first, wait for its status light to settle (the PON/link lamp steady, not blinking), then the router. Genset owners: the box's switching power supply does not care about the generator's waveform, but a cheap phone-charger-style brick may, and a flickering router is a brown-out tell before it is a fault. Internet is a chain of appliances; treat the two boxes like the fridge - on the power you planned for, not the one you remembered.