Backing up a home network: routers, modems, NAS, and the UPS spec that actually matters
The most common "my first blackout" lesson: you have a power station, the fridge is fine, your phone is charging — and you discover your home internet has been down since the lights went out, because the cable modem and router lost power three hours ago and your phone has no LTE signal at your house. Backing up the network is a separate problem from backing up the fridge. Here's how to do it right.
How much power does home network gear actually draw?
Far less than you'd guess. Independent ENERGY STAR networking equipment measurements:
- Cable or fiber modem: 6–12 W
- Wi-Fi router (consumer dual-band, e.g., Asus AX86U, Eero, Netgear Nighthawk): 10–18 W
- Mesh node satellite: 8–14 W each
- VoIP phone base station: 3–6 W
- Small NAS (Synology DS220+ idle): 10–15 W; under disk activity 25–35 W
Add it up: a typical home network (modem + router + one mesh satellite + small NAS at idle) draws 35–50 W continuously. A 1 kWh power station runs all of that for 17–25 hours.
UPS switchover matters more for networks than for fridges
This is where people get caught. A fridge doesn't care if power drops for 5 seconds — the compressor restarts and everything is fine. A modem or router rebooting takes 90–180 seconds to fully renegotiate with the ISP, and many cable modems re-handshake DOCSIS in a way that ties up your IP for several minutes after the reboot completes.
If your power station has UPS pass-through with sub-25 ms switchover, the modem and router don't see the outage at all. If switchover is 30+ ms, most modern routers will reboot. FCC broadband resiliency documentation discusses these timing requirements in their carrier guidelines — same physics applies to your home equipment.
See our UPS switchover guide for the model-by-model breakdown of what each major brand actually delivers in real-world tests.
What about the wider mesh?
Mesh satellites that need to be powered at multiple physical locations are the hardest problem. Three options, in order of cost:
- Move them all to one location during the outage. Less coverage, but the network stays up.
- Small individual UPS batteries. APC BE600M1 ($60) or similar provides 30–60 minutes of router-only runtime. Useful as gap filler while you bring the main power station to the spot.
- Multiple power stations. Overkill unless the house is large and the outages are frequent.
The 24-hour internet checklist
- Verify your ISP's gear works on battery — some cable modems require utility power to authenticate; most do not. Test by plugging both modem and router into the power station's UPS outlet and pulling the wall plug.
- Confirm switchover time. Plug your laptop into the same UPS outlet, run a speed test, and yank wall power mid-test. If the test completes uninterrupted, you're fine.
- Identify which power outlet on the unit is the UPS pass-through one — not every AC outlet on every unit functions as UPS.
- Calculate runtime: total network gear watts × hours / (0.88 × 0.92) = required Wh. Add 30% headroom for unexpected loads.
- Test once a quarter. UPS function is one of the spec sheet items most likely to drift after firmware updates.
Sources & further reading
- ENERGY STAR Networking Equipment — U.S. Environmental Protection Agency
- Broadband Network Resiliency — Federal Communications Commission
- Network Outage Reporting System (NORS) — Federal Communications Commission