Best UPS options for keeping a smart home alive during outages
The best UPS picks for Home Assistant servers, network gear, and hubs, with NUT integration so your automations keep running through a power outage.
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A local-first smart home that dies every time the power blinks is not actually resilient. You’ve done the work to keep everything off the cloud. Now keep it off the floor when the lights go out.
Here’s where we’d start:
- Budget pick: APC Back-UPS BE600M1
- Mid-range pick: CyberPower CP1500PFCLCD
- Premium pick: APC Smart-UPS SMT1500C
What actually needs a UPS
Battery-powered Zigbee and Z-Wave sensors keep running during an outage, but the mesh they report through does not. Routing is done by your mains-powered devices — bulbs, plugs, in-wall switches — and those die with the power, while battery sensors are end devices that never route for themselves. So a UPS buys you the brain and the path to it, not the whole mesh. That means your hub, your router, and the switch connecting them.
Plug these in:
- your Home Assistant box (a Green, a mini PC, or an older Yellow - the Yellow was discontinued in October 2025) - see choosing the right power supply for Home Assistant if you also run one off a bare DC brick
- your router
- one PoE switch if you run PoE access points or cameras
- a mains-powered Zigbee or Z-Wave router near any sensor that must keep reporting through a cut — a single smart plug is enough to keep that hop alive
Do not plug these in:
- monitors
- printers
- laser printers especially (massive draw on startup)
- anything with a heating element
- anything you wouldn’t miss for an hour
The goal is runtime, not convenience. Every watt you waste on a monitor is a minute your automations lose.
What matters in a smart home UPS
Sine wave output. Simulated sine wave (stepped approximation) is fine for routers and most hubs. But if you’re running a mini PC or NAS, a pure sine wave UPS avoids weird shutdowns and power supply stress. The CyberPower CP1500PFCLCD and APC Smart-UPS lines are pure sine wave. The budget APC BE600M1 is simulated, which is acceptable for a hub and router but not ideal for more sensitive gear.
Runtime at your actual load. A Home Assistant Green, a router, and a small switch together pull maybe 30-40W. At that load even a 600VA unit gives you 30+ minutes. A 1500VA pure sine wave unit can keep a mini PC and full network stack alive for over an hour. Check the manufacturer’s runtime charts at your expected wattage, not the headline VA number.
USB or network management port. This is the piece most people skip. A UPS with a USB HID interface lets your system detect power loss and shut down gracefully. Better yet, it feeds into NUT (Network UPS Tools), which integrates directly with Home Assistant.
NUT integration with Home Assistant. The Home Assistant NUT integration exposes battery level, load, runtime remaining, and power state as sensors. You can build automations around it: send a notification when power drops, trigger a graceful shutdown at 20% battery, or log outage duration. If your UPS supports NUT over USB, this is nearly zero effort to set up.
Budget: APC Back-UPS BE600M1
APC Back-UPS BE600M1 is the right choice when you just need to keep a hub and a router alive. It’s small, cheap, has a USB charging port on the front, and provides a USB HID interface for NUT.
The tradeoffs: simulated sine wave, limited runtime under heavier loads, and no network management card. For a Home Assistant Green or Hubitat plus a router, it’s plenty. For a mini PC setup, step up.
Mid-range: CyberPower CP1500PFCLCD
CyberPower CP1500PFCLCD is the sweet spot for most serious smart home setups. Pure sine wave output, 1500VA/1000W capacity, an LCD panel showing real-time stats, and USB HID support for NUT.
This comfortably handles a mini PC running Home Assistant, a router, a PoE switch, and a few peripherals. At a typical smart home load of 80-100W, you’re looking at well over an hour of runtime. It’s the one we’d pick for most people running a local-first stack.
Premium: APC Smart-UPS SMT1500C
APC Smart-UPS SMT1500C is for the rack crowd - though the SMT1500C itself is a tower unit, so if you actually need it in the rack, buy the 2U SMT1500RM2UC instead. Pure sine wave, 1500VA/1000W, and a SmartSlot for a network management card (sold separately - that card is what gets you SNMP and NUT over the network instead of USB), plus a SmartConnect port for APC’s cloud monitoring if you want it.
This is overkill for a single hub and router. It makes sense when you have a proper network rack, multiple switches, a NAS, and a dedicated Home Assistant server. The network management card also means the UPS itself can be monitored from any machine on the network, not just the one plugged into the USB port.
Setting up NUT in Home Assistant
If the UPS plugs into the Home Assistant machine itself, install the Network UPS Tools community add-on (Home Assistant OS or Supervised only), then add the NUT integration and point it at the add-on. If the UPS is plugged into a NAS that already runs a NUT server, skip the add-on and point the integration straight at the NAS. Either way you get sensors for:
- battery charge percentage
- estimated runtime remaining
- input/output voltage
- UPS load percentage
- UPS status (online, on battery, low battery)
From there, build a simple automation: if UPS status switches to “on battery,” send a push notification. If battery drops below 20%, trigger a graceful shutdown script. This closes the loop on a properly resilient local-first setup.