Electrical safety review, August 9, 2026: Bemo Editorial manually checked outlet, grounding, load, waveform, and battery-service cautions against the current manufacturer pages. Follow the exact model manual.
The CyberPower ST425 is the best-value UPS for a basic modem and router. Its 260W output is already ample for a small network stack, CyberPower explicitly lists broadband routers among its applications, and four of its eight outlets receive battery power.[1]
Choose the APC BE600M1 when you want a larger UPS with a user-replaceable battery and five battery-backed outlets. Choose the CyberPower CP1500PFCLCD or APC BR1500MS2 only when the UPS will also support a desktop, NAS, or equipment that benefits from sine-wave output.
These recommendations compare published specifications, not hands-on battery tests. Measure your network and test the final setup before relying on it.
Specifications checked: August 9, 2026. Match the exact model number and electrical rating before buying.
For the complete preparedness and safety plan, return to Power Outage Solutions: The Complete Blackout Guide.
Quick picks
CyberPower ST425
A compact, inexpensive UPS whose 260W output is already more than a basic network stack needs.
- Four battery-backed outlets
- Compact 3.8 lb design
- CyberPower lists routers and modems as an intended application
- Small 2.9Ah battery
- Battery is not user-replaceable
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APC BE600M1
Five battery-backed outlets and an owner-replaceable battery make this a more serviceable step-up for a modem, ONT, router, and other small network devices.
- Five battery-backed outlets
- User-replaceable APCRBC154 battery cartridge
- USB charging port remains useful during an outage
- Stepped approximation to a sine wave on battery
- No USB data connection for computer shutdown
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CyberPower CP1500PFCLCD
A 1000W sine-wave UPS with AVR and a user-replaceable battery, justified when the load extends beyond networking.
- Sine-wave output
- Six battery-backed outlets
- User-replaceable battery and USB management
- Excess output for router-only use
- 24.9 lb and much larger than compact options
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APC Back-UPS Pro BR1500MS2
A 900W sine-wave alternative with AVR, six battery-backed outlets, LCD status, and a user-replaceable battery.
- Sine-wave battery output
- User-replaceable battery
- AVR and USB-A plus USB-C charging
- Overkill for a modem and router alone
- Large tower footprint
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Comparison
How we selected these UPS units
We started with the complete measured network load, not VA, and required a current US manufacturer specification page. For router-only candidates, we prioritized battery energy, low-load suitability, battery-backed outlet count, and physical size. For mixed network-and-computer candidates, we added waveform, automatic voltage regulation, transfer time, management support, and user-replaceable batteries. Published half-load runtimes were treated only as reference points because they do not predict runtime at a 10 to 30W network load.
We did not conduct comparative discharge or transfer-time tests, so “best” labels mean the strongest specification fit for the named scenario, not a universal laboratory winner. Load-test the final setup with the actual modem, ONT, router, switches, and computers.
Why the smallest pick is best for most networks
Output is not the same as runtime. A 1500VA UPS can support a much larger instantaneous load, but that does not guarantee proportionally longer runtime at a tiny 15W load. Inverter overhead and the manufacturer’s low-load curve matter.
The ST425 publishes 1.5 minutes at its full 260W load and six minutes at half load.[1] Those figures do not predict router-only runtime. They show why you must measure the actual stack and run a controlled test.
For most people, the ST425 wins because it avoids paying for computer-class output. Its disadvantage is a small, non-user-replaceable battery. If longevity and serviceability outweigh initial cost, skip to a larger model with a documented replacement cartridge.
Why the APC BE600M1 is the serviceable step-up
APC rates the BE600M1 at 600VA and 330W. It provides five battery-backed and surge-protected outlets, two surge-only outlets, and a USB charging port. APC also specifies the APCRBC154 as an owner-replaceable battery cartridge.[2] For a home network, the serviceable battery and additional backed-up outlet are more useful than the modest increase in maximum output.
The USB port supplies charging power rather than computer-management data. Choose one of the 1500VA models below if automated computer or NAS shutdown is part of the plan.
When a sine-wave 1500VA UPS makes sense
The CP1500PFCLCD supplies 1000W, sine-wave battery output, AVR, six battery-backed outlets, a 4ms typical transfer time, and user-replaceable batteries. CyberPower publishes ten minutes at half load and 2.5 minutes at full load.[3]
Those load points are hundreds of watts, so they still do not answer a 15W router-runtime question. Buy it when you need its waveform, output, outlets, AVR, management, or replaceable battery, not because 1500VA appears to promise all-day Wi-Fi.
APC’s BR1500MS2 is a closely matched alternative at 1500VA and 900W, with sine-wave battery output, AVR, ten outlets, six battery-backed outlets, and a user-replaceable battery.[4] Choose between them based on current model support, replacement-battery availability, outlet layout, and your measured load.
Map the complete internet power path
Your Wi-Fi router may not be the device that connects the home to the provider. Trace the cable:
- Fiber service may use a separate optical network terminal.
- Cable service uses a modem, whether separate or combined with the router.
- Fixed wireless may have a powered indoor receiver or PoE injector.
- Mesh systems need power at each node, though only the gateway node may be essential.
- A network switch or PoE switch may power cameras and access points.
Put every required local device on a battery-backed outlet. Leave printers and other nonessential loads off the UPS. CyberPower explicitly warns against high-drain equipment such as laser printers and space heaters on the ST425.[1]
How much runtime do you need?
- 5 to 15 minutes: enough to bridge brief interruptions.
- 30 to 60 minutes: useful for common local outages and an orderly shutdown.
- Several hours: measure carefully and compare a larger UPS against a portable power station.
- All day: a UPS alone is rarely the most economical architecture; consider a larger battery with a documented UPS function or DC backup designed for the network equipment.
Use How Long Will a UPS Run a Wi-Fi Router? for the calculation and test method.
UPS versus portable power station for Wi-Fi
A UPS transfers automatically and is designed to sit between the wall and equipment. A portable power station usually stores more energy per dollar and can power other devices, but only models with a documented UPS or EPS feature should be expected to transfer automatically.
For a five-minute flicker, choose a UPS. For an eight-hour outage, compare the UPS runtime curve with a measured portable power station size.
Final recommendation
Buy the CyberPower ST425 for a basic modem, router, and ONT when value matters most. Step up to the APC BE600M1 when you want five battery-backed outlets and a user-replaceable battery. Buy the CP1500PFCLCD or APC BR1500MS2 only when you also need to support a computer, NAS, or waveform-sensitive equipment.
Whatever you choose, measure the complete network stack, use only battery-backed outlets for essential devices, and test whether the provider connection actually remains available when utility power is removed.
FAQ (Frequently Asked Questions)
What is the best UPS for a modem and router?
For a basic modem and router, the CyberPower ST425 is the best-value starting point because CyberPower explicitly lists routers and modems as an application, and its 260W ceiling is already far above a typical small network load. Choose the APC BE600M1 when you want a larger, user-replaceable battery, or a sine-wave 1500VA unit when the UPS will also protect a desktop, NAS, or equipment whose manufacturer requires that waveform.
Will a UPS keep Wi-Fi working during a power outage?
It keeps your local network equipment powered. Internet still depends on the provider’s network, the fiber ONT or cable modem, neighborhood equipment, and any other required device. Put every required local box on battery-backed outlets and test service during a real or controlled outage.
How long will a UPS run a Wi-Fi router?
Runtime depends on total measured watts, the UPS runtime curve, battery age, temperature, and conversion losses. A router-only load can last much longer than manufacturer half-load figures suggest, but the only dependable answer is a controlled test with the modem, router, ONT, and mesh nodes you actually use.
Do I need a 1500VA UPS for a router?
Usually not for wattage. A modem and router may draw only a small fraction of 1500VA UPS output. A larger unit can provide more stored energy and a replaceable battery, but it also costs more and occupies more space. Compare low-load runtime and battery serviceability instead of VA alone.
Should the modem and router both be connected to the UPS?
Yes, along with the fiber ONT, PoE injector, or other device required for the internet connection. Plugging in only the Wi-Fi router preserves the local wireless network but cannot keep an unpowered modem or ONT online.