Best battery backups to keep your Wi-Fi on in a power outage (2026)
A UPS (uninterruptible power supply) switches to its battery the moment the power cuts, so your modem and router stay on and a desktop computer gets time to shut down safely. Ready.gov suggests finding out whether your home phone will work in an outage and how long its battery backup lasts; if your phone runs over your internet connection, that means keeping the modem powered. Here are the models worth buying.
By PreparedStates editors · Updated October 22, 2026 · 5 products, prices indicative
Our picks
APC BE600M1
Keeping a modem and router online
APC BR1500MS2
Sensitive electronics and desktop PCs
CyberPower CP1500PFCLCD
The most capacity here, with sine-wave output
All 5 compared
| UPS | Rating | Outlets | Output on battery | Runtime (maker) | Price |
|---|---|---|---|---|---|
600VA · 5 battery backup, 2 surge-only, USB charging port · 23 min at 100 W (maker) Keeping a modem and router online | 600VA | 5 battery backup, 2 surge-only, USB charging port | — | 23 min at 100 W (maker) | |
Our verdictOur verdictResearched The classic small UPS for a modem and router: APC rates it at 23 minutes with a 100 W load, and a modem and router draw much less than that. The USB port charges a phone during an outage. Best for Keeping a modem and router online Good
Worth knowing
Who shouldn't buy it: Don't buy it if you need to keep a desktop computer and monitor running. | |||||
1500VA / 900W · 6 battery backup, 4 surge-only · Pure sine wave Sensitive electronics and desktop PCs | 1500VA / 900W | 6 battery backup, 4 surge-only | Pure sine wave | — | |
Our verdictOur verdictResearched Pure sine wave output, which suits desktop computers with active PFC power supplies, plus six battery-backup outlets. Best for Sensitive electronics and desktop PCs Good
Worth knowing
Who shouldn't buy it: Don't buy it if you only need to keep a modem and router running. | |||||
1500VA / 1000W · 6 battery backup, 6 surge-only · Sine wave The most capacity here, with sine-wave output | 1500VA / 1000W | 6 battery backup, 6 surge-only | Sine wave | — | |
Our verdictOur verdictResearched 1,000 W of sine-wave backup over six outlets: the most capacity on this page, for a desktop, monitors and networking gear together. Best for The most capacity here, with sine-wave output Good
Worth knowing
Who shouldn't buy it: Don't buy it if you only need to keep a modem and router running. | |||||
1500VA / 900W · 5 battery backup, 5 surge-only A home office: computer, monitor and router | 1500VA / 900W | 5 battery backup, 5 surge-only | — | — | |
Our verdictOur verdictResearched 900 W of backup across five outlets, enough for a desktop, monitor and router through a short outage, with automatic voltage regulation for brownouts. Best for A home office: computer, monitor and router Good
Worth knowing
Who shouldn't buy it: Don't buy it if you only need to keep the internet on: the BE600M1 is smaller. | |||||
850VA / 510W · 5 battery backup, 5 surge-only · Sine wave Sine-wave output at a mid size | 850VA / 510W | 5 battery backup, 5 surge-only | Sine wave | — | |
Our verdictOur verdictResearched Sine-wave output in a mid-size unit: more headroom than a router-only UPS for a small computer setup, with an LCD showing load and runtime. Best for Sine-wave output at a mid size Good
Worth knowing
Who shouldn't buy it: Don't buy it if you need to run a gaming PC. | |||||
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Before you buy
Size it to what you'll plug in.
A modem and router draw little, so a small 600VA unit runs them much longer than its runtime figure at 100 W; a desktop computer needs a 1500VA-class unit.
Use the right outlets.
Most UPS units have battery-backup outlets and surge-only outlets: the modem and router go in the battery-backup ones.
Sine-wave output (APC BR1500MS2, the CyberPower PFC Sinewave models) suits desktop computers with active PFC power supplies.
For a modem and router, any of these works.
The battery wears out and is replaceable.
Check the replacement battery model before you buy.
We verify every product's specifications against at least two independent sources, re-check its US price and stock on a schedule where we can track it automatically, and cross-check safety-relevant claims against official guidance. Every review is labelled Researched or Used and reviewed by us: where we've bought a product, or been sent it free, and used it ourselves, its review says which; where we haven't, our verdict is a considered spec-and-evidence comparison, not a hands-on test — and commissions never change a ranking either way. Read our full methodology →
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Common questions
How long will a UPS keep my Wi-Fi on?
It depends on the battery and the load. APC rates its BE600M1 at 23 minutes with a 100 W load; a modem and router usually draw far less than that, so it runs them for longer. Check your devices' power ratings.
What's the difference between VA and watts?
Both are ratings of how much the UPS can supply; size by watts. Add up the watts of what you'll plug in and stay under the UPS's watt rating.
Do I need a pure sine wave UPS?
For a modem and router, no. Sine-wave models suit desktop computers with active PFC power supplies and other sensitive electronics.
Will my internet work in a power outage?
Only if your provider's equipment still has power. Ready.gov suggests checking whether your home phone will work in an outage and how long its battery backup will last.