Best UPS for Home Assistant, Router and NAS

Quick Summary (TL;DR):
For a Home Assistant setup with a router and NAS, choose the UPS by watts, VA, shutdown support and outlet type rather than buying the largest number on the box. A practical 230V shortlist is the APC Back-UPS Pro BR900G2-GR for a compact Schuko-based setup, the CyberPower CP1500EPFCLCD for more capacity and pure-sine output, and the Eaton 5SC1000I for a storage/server-oriented installation with clean sine-wave output and USB HID communication. The UPS does not need to keep a NAS running for hours; the priority is to keep Home Assistant and the router alive through short outages and give the NAS enough time to shut down cleanly. Size the UPS from the actual combined watt load, leave sensible headroom, verify that your exact NAS supports the UPS communication interface, and test an automatic shutdown before relying on it. Home Assistant can monitor supported UPS hardware through the Network UPS Tools integration, but Home Assistant itself talks to a NUT server, not directly to the USB UPS.

Best UPS for Home Assistant, Router and NAS at a Glance

UPS	Capacity	Output / outlets	Why choose it
APC BR900G2-GR	900VA / 540W	230V, 4 × Schuko	Compact all-in-one choice for router, HA host and small NAS
CyberPower CP1500EPFCLCD	1500VA / 900W	Pure sine, 6 × Schuko	More headroom, active-PFC compatibility and replaceable battery
Eaton 5SC1000I	1000VA / 700W	Sine wave, 8 × IEC C13	Server/NAS-oriented UPS with USB HID and serial communication
APC BR1300MI	1300VA / 780W	230V, 8 × IEC C13	More APC capacity when several IEC-powered devices share one UPS

These are not ranked purely by battery size. They fit different installations.

What the UPS Is Actually Protecting

A smart-home UPS often powers three very different classes of equipment:

• Home Assistant host: Home Assistant Green, Raspberry Pi, mini PC or Proxmox server.
• Network equipment: router, fibre ONT, modem, switch and perhaps Wi-Fi access point.
• Storage: two-bay or four-bay NAS with spinning hard drives.

The first two benefit from staying online during short outages. The NAS mainly needs enough battery time and communication support to complete a controlled shutdown before the UPS is exhausted.

Do Not Size a UPS by VA Alone

A UPS normally has both a VA rating and a watt rating.

For example:

• APC BR900G2-GR: 900VA / 540W.
• CyberPower CP1500EPFCLCD: 1500VA / 900W.
• Eaton 5SC1000I: 1000VA / 700W.

Your connected equipment must remain below both limits.

The dedicated sizing guide later in this series goes deeper into power factor and measurement: UPS VA vs Watts: Sizing Backup Power for NAS, Router and Server.

Measure the Real Load Before Buying

The safest method is to measure the complete protected equipment with a plug-in power meter.

Measure the system during a realistic busy condition:

• NAS drives active.
• Mini PC running its normal applications.
• Router and switches connected.
• Any PoE devices powered if they will also be on the UPS.

Then choose a UPS with comfortable capacity above that measured load. Avoid operating a UPS continuously near its maximum watt rating because battery runtime collapses as load rises and future expansion leaves no margin.

A Useful Sizing Formula

For a first pass:

Required UPS watts
≈ measured protected load × 1.25 to 1.5

This is a planning margin, not a law. The final decision should also consider the manufacturer’s runtime curve at your actual load.

Runtime: Think in Terms of Shutdown Time

A common mistake is to ask, “How long will this UPS run my NAS?” without defining the goal.

For a Home Assistant/router/NAS stack, useful targets are usually:

• Ride through very short outages without rebooting anything.
• Keep the router and Home Assistant available while the power interruption is brief.
• Give the NAS several minutes to shut down cleanly if the outage continues.
• Preserve some battery reserve rather than running until the UPS dies.

UGREEN’s current NAS guidance recommends leaving roughly a 5–10 minute controlled-shutdown window rather than trying to use every last percentage of battery capacity.

APC Back-UPS Pro BR900G2-GR: Best Compact Schuko Choice

The APC BR900G2-GR is particularly convenient in Greece and other Schuko markets because it provides four Schuko outlets rather than IEC-only sockets.

• 900VA.
• 540W.
• 230V.
• Four Schuko outlets.
• Automatic Voltage Regulation (AVR).
• LCD status display.
• User-replaceable battery.
• Data port for APC PowerChute Serial Shutdown communication.
• Two USB-C charging ports.

That makes it easy to connect equipment that already uses normal domestic plugs: router, fibre ONT, mini PC power brick and a small NAS.

Who it suits

• Home Assistant Green or a low-power mini PC.
• Router + ONT.
• Small two-bay NAS.
• Users who prefer Schuko sockets without IEC adapters.
• Moderate total load where 540W output is comfortably sufficient.

Do not assume every APC USB-capable model is supported by every NAS. Check the NAS vendor’s UPS compatibility list before relying on automated shutdown.

CyberPower CP1500EPFCLCD: Best Pure-Sine High-Headroom Choice

The CyberPower CP1500EPFCLCD steps up substantially in capacity.

• 1500VA.
• 900W.
• Line-interactive topology.
• Pure sine-wave output on battery.
• AVR.
• Six Schuko outlets in the European version.
• HID-compliant USB communication.
• LCD status display.
• User-replaceable sealed lead-acid battery.
• Official half-load runtime figure of 10 minutes.

CyberPower explicitly positions this PFC Sinewave series for systems using conventional or active-PFC power supplies.

Network UPS Tools also lists the CP1500EPFCLCD as a supported USB HID device with tested shutdown commands, which makes it particularly interesting for NUT-based Home Assistant monitoring.

Who it suits

• Four-bay NAS plus mini PC.
• Router, ONT and switch on the same UPS.
• Users who specifically want pure-sine output.
• Higher combined load or longer short-outage ride-through.
• NUT-based monitoring where compatibility has been verified.

1500VA does not mean you should load it with 1500W. Its real-power ceiling is 900W.

Eaton 5SC1000I: Best Server/NAS-Oriented Choice

The Eaton 5SC1000I is less domestic-looking and more obviously designed for servers, networking and storage.

• 1000VA.
• 700W.
• Line-interactive topology.
• Sine-wave output.
• AVR.
• Eight IEC C13 outlets.
• LCD display.
• USB HID communication.
• RS-232 serial communication.
• User-replaceable battery.
• Eaton Advanced Battery Management.
• Automatic shutdown support.

The IEC outlets are ideal in a small equipment cabinet but less convenient if every device currently uses a moulded Schuko plug. Check the cabling before ordering.

Who it suits

• NAS and server hardware using IEC leads.
• Small racks or equipment cabinets.
• Users prioritising HID communication and controlled shutdown.
• Installations where clean sine-wave output is desirable.

APC BR1300MI: A Higher-Capacity APC Alternative

If you prefer APC but the 900VA model is too small, the BR1300MI increases capacity to 1300VA / 780W and provides eight IEC C13 outlets, AVR, an LCD and a user-replaceable battery.

It makes more sense when several IEC-powered devices share the UPS or when the measured load and required runtime justify moving beyond 540W.

Pure Sine Wave vs Other UPS Waveforms

A pure-sine UPS reproduces a smooth AC waveform while running from battery. The CyberPower CP1500EPFCLCD and Eaton 5SC1000I explicitly specify sine-wave output.

Pure sine is a useful preference when protecting equipment with active-PFC power supplies or when you want the least waveform-related uncertainty. However, do not reject a UPS solely because the marketing page does not use the words “pure sine” without first checking compatibility with the equipment you actually own.

AVR Matters More Than Many Buyers Realise

Automatic Voltage Regulation lets a line-interactive UPS correct some low or high mains-voltage conditions without switching to battery.

This is useful because:

• The battery is not consumed for every minor voltage fluctuation.
• Connected equipment sees more stable voltage.
• Battery cycling can be reduced.

All three main models in this shortlist include AVR.

USB Communication Is More Important Than an LCD

An LCD is useful, but the critical feature for a NAS is a communication path that tells the NAS that mains power has failed.

Utility power fails
      ↓
UPS switches to battery
      ↓
USB / network status reaches NAS
      ↓
NAS waits configured time
      ↓
NAS performs clean shutdown

A UPS that supplies battery power but cannot communicate with the NAS may still allow the NAS to crash abruptly when the battery finally empties.

Synology, QNAP and UGREEN Can Use UPS Shutdown Signalling

Current Synology DSM systems support USB and network UPS configurations under Control Panel → Hardware & Power → UPS. DSM can also act as a network UPS server.

QNAP QTS supports compatible USB or SNMP UPS hardware under Control Panel → System → External Device → UPS, with options including delayed shutdown and network UPS master operation.

UGREEN’s current UGOS Pro can detect compatible USB-connected UPS hardware, display battery/runtime status and trigger Standby Mode or Auto Shutdown. UGREEN also added a NUT Server mode for sharing UPS status with other compatible clients.

Always check the current vendor compatibility list for your exact NAS and UPS model before purchase.

How Home Assistant Monitors a UPS

Home Assistant has an official Network UPS Tools (NUT) integration.

Important: Home Assistant does not communicate directly with the UPS through this integration. It connects to a NUT server.

UPS
 ↓ USB
NUT server
 ↓ network
Home Assistant NUT integration

The NUT integration can expose information such as battery charge, UPS load, input/output voltage, status and other variables supported by the particular device.

Home Assistant can then notify you when the UPS goes on battery or when charge drops below a chosen level.

Our dedicated setup guide is planned at Network UPS Tools with Home Assistant and NAS: Safe Automatic Shutdown.

Which Device Should Own the USB UPS Connection?

If the NAS contains important writable storage, a sensible default is to connect the UPS communication cable directly to the NAS and let the NAS control its own safe shutdown.

If that NAS can act as a NUT or network UPS server, other systems can consume the power status over the network.

This avoids making NAS safety depend entirely on Home Assistant being online.

Keep the Router and Network Switch on Battery

If the router loses power immediately, Home Assistant may continue running but remote notifications, cloud integrations and network UPS signalling can disappear.

Protect the minimum network chain required for your environment:

• Router/firewall.
• Fibre ONT or modem.
• Essential Ethernet switch.
• Home Assistant host.
• NAS.

If the Wi-Fi access points are PoE-powered, remember that the PoE switch may be one of the largest loads on the UPS.

Do Not Put Everything in the House on the UPS

Battery capacity is finite. Avoid wasting runtime on equipment that does not need clean shutdown or short-outage continuity.

Examples that usually do not belong on the same smart-home UPS include:

• Laser printers.
• Large monitors.
• Desktop gaming PCs unless intentionally included in the sizing.
• Audio amplifiers.
• Non-critical chargers.

Laser printers in particular can have high transient loads and should not be connected to a small UPS battery output unless the UPS manufacturer specifically supports that use.

Schuko vs IEC Outlets

Outlet type is easy to overlook until the UPS arrives.

Model	Main output style	Practical consequence
APC BR900G2-GR	Schuko	Easy for consumer power bricks
CyberPower CP1500EPFCLCD	Schuko	Easy mixed home/network setup
Eaton 5SC1000I	IEC C13	Excellent for rack/server cabling; adapters may be required for wall-plug bricks
APC BR1300MI	IEC C13	Good equipment-cabinet layout

Replaceable Batteries Matter

The battery is a consumable component. A good UPS chassis can outlive its first battery by years.

All three main recommendations here use replaceable batteries. When comparing total ownership cost, include:

• Replacement battery availability.
• Battery cost.
• Warranty.
• Ease of replacement.
• Local recycling/disposal options.

What About UGREEN’s Small DC UPS?

UGREEN now sells compact UPS units such as the US3000 for compatible NASync systems. UGREEN lists the US3000 at up to 120W output with USB communication to supported NAS models.

This can be elegant if the only goal is protecting one compatible UGREEN NAS.

It is not a replacement for an AC UPS when you also need to keep the router, ONT, Ethernet switch and separate Home Assistant mini PC running. For a whole smart-home stack, a conventional AC UPS is far more flexible.

How Long Should You Delay NAS Shutdown?

There is no universal number.

A sensible design balances two goals:

• Do not shut the NAS down for every two-second flicker.
• Do not wait so long that there is insufficient battery left for a clean shutdown.

QNAP’s current guidance uses an example recommendation of roughly 3–5 minutes before shutdown. UGREEN emphasises retaining a 5–10 minute controlled-shutdown window. Treat these as configuration guidance rather than universal runtime requirements.

Test the UPS Before You Trust It

After configuration, perform a controlled outage test during a quiet maintenance window.

1. Finish important transfers.
2. Confirm the UPS battery is charged.
3. Confirm the NAS detects the UPS.
4. Disconnect mains power from the UPS input.
5. Verify that the UPS reports battery operation.
6. Confirm Home Assistant receives the expected NUT status if configured.
7. Wait for the NAS shutdown trigger.
8. Confirm the NAS shuts down cleanly.
9. Restore mains power.
10. Verify expected automatic restart behaviour.

Do not discover during the first real blackout that the USB data cable was never connected or that the NAS does not recognise the UPS.

A UPS Is Not a Backup

A UPS reduces the risk of interrupted writes and unclean shutdowns. It does not protect you from:

• Drive failure.
• Accidental deletion.
• Ransomware.
• Filesystem corruption unrelated to power.
• Theft.
• Fire or water damage.

Keep independent backups even when the NAS is protected by a UPS.

Which UPS Should You Choose?

Your setup	Recommended direction	Why
Router + HA host + small NAS	APC BR900G2-GR	540W, Schuko convenience, AVR, replaceable battery
Four-bay NAS + mini PC + network stack	CyberPower CP1500EPFCLCD	900W ceiling, pure sine, six Schuko outlets, HID USB
Equipment cabinet / IEC cabling	Eaton 5SC1000I	700W, sine wave, 8 × C13, USB HID + serial
Larger APC-based IEC setup	APC BR1300MI	780W and eight C13 outlets
Only one compatible UGREEN NAS	UGREEN US3000-type DC UPS	Compact NAS-specific protection, but not whole-network power

Best UPS for Home Assistant, Router and NAS: The Bottom Line

The best smart-home UPS is not automatically the one with the highest VA number. Start with the measured watt load, decide how long the system must remain usable, verify NAS communication support and choose the correct outlet type.

For a compact Greek/European setup, the APC BR900G2-GR is a convenient starting point. For a larger NAS and mini-PC stack, the pure-sine CyberPower CP1500EPFCLCD provides substantially more headroom. Eaton’s 5SC1000I is especially attractive when IEC cabling, USB HID communication and server/storage-oriented power management suit the installation.

Whichever model you choose, configure and test the automatic NAS shutdown. A UPS that only delays an eventual hard power cut is not doing the most important part of the job.

Continue the UPS and Home Server Series

• UPS VA vs Watts: Sizing Backup Power for NAS, Router and Server
• APC vs CyberPower vs Eaton UPS for Home Servers
• Network UPS Tools with Home Assistant and NAS: Safe Automatic Shutdown

Datasheets & External Resources

• APC BR900G2-GR – Official Schneider Electric specifications
• APC BR1300MI – Official Schneider Electric specifications
• CyberPower CP1500EPFCLCD – Official specifications
• Eaton 5SC1000I – Official specifications
• Home Assistant – Network UPS Tools integration
• Network UPS Tools – CP1500EPFCLCD device listing
• Synology DSM – USB/network UPS configuration
• QNAP – Configure USB or network UPS protection
• UGREEN – Connect and configure UPS protection in UGOS Pro