Best small UPS for a home NAS, with a safe shutdown (2026)
Updated 2026-11-08
Short answer. If your NAS is a UGREEN NASync 2- or 4-bay (DXP2800, DXP4800 Plus, DXP4800 Pro, DXP480T Plus, DH2300, DH4300 Plus), buy the UGREEN NAS UPS US3000 ($109.99; buy: https://dealectric.com/go/ugreen-nas-ups-us3000-120w), $109.99 on 2026-11-03: a 120 W lithium battery that sits inline on the NAS's own DC lead, switches over in 0 seconds, and tells UGOS over USB to shut down at once, after a set time, or before the battery runs out; UGREEN quotes about 10 minutes of runtime. For any other NAS, the small AC unit to buy is the APC Back-UPS BE600M1 (600 VA / 330 W, USB shutdown, about $135–140): it is on UGOS's own supported list and on Synology's and QNAP's.
Two things to know. The US3000 powers only the NAS, not the router or switch, so remote access drops during the outage even though the data stays safe; and no lab has measured its runtime, the figures are UGREEN's 10 minutes and reviewers' 7–10 minute estimates at 35–55 W. For a NAS with an active-PFC power supply, or a 6- or 8-bay that the US3000 does not support, the CyberPower CP850PFCLCD (850 VA / 510 W, pure sine wave on battery, three-year warranty) is the safe AC pick.
- UGREEN NAS UPS US3000 (DC, NASync 2–4 bay), $109.99. Buy: https://dealectric.com/go/ugreen-nas-ups-us3000-120w
Published 2026-11-03 · prices checked 2026-11-03.
| Model | Rating | Waveform on battery | USB shutdown | Runtime (maker or reviewer) | Warranty | Price | Code |
|---|---|---|---|---|---|---|---|
| UGREEN NAS UPS US3000 (DC, NASync 2–4 bay) Buy: https://dealectric.com/go/ugreen-nas-ups-us3000-120w | 120 W DC, 43.2 Wh lithium | DC inline, 0 s transfer | USB to UGOS: Auto, Timed or Standby shutdown; NUT server toggle | About 10 min (UGREEN); 7–10 min estimated at 35–55 W (reviews) | 2 years | $109.99 | No discount code applies. |
| UGREEN NAS UPS US2000 (DC, DH series and DXP2800) | 72 W DC, 43.2 Wh lithium | DC inline, 0 s | USB to UGOS | Not published | 2 years | $69.99 (UGREEN NAS store, 2026-11-03) | Not sold through Dealectric; listed for comparison. |
| APC Back-UPS BE600M1 | 600 VA / 330 W | Simulated sine | USB data port; on UGOS's, DSM's and QTS's lists | 67 min at 40 W, 10 min at 180 W (APC datasheet) | 3 years (retailers) | about $135–140 (SHI, undated) | Not sold through Dealectric; listed for comparison. |
| APC Back-UPS BE425M | 425 VA / 255 W | Simulated sine | Not stated | 45 min at 40 W (APC datasheet) | Not found | about $77–80 (MSRP $106) | Not sold through Dealectric; listed for comparison. |
| APC Back-UPS BE850M2 | 850 VA / 450 W | Simulated sine | Not stated | 90 min at 40 W, 14.8 min at 180 W | Not found | Not found | Not sold through Dealectric; listed for comparison. |
| CyberPower CP850PFCLCD | 850 VA / 510 W | Pure sine (line-interactive) | USB | 2 min at full load (retailer) | 3 years + connected-equipment guarantee | Not found | Not sold through Dealectric; listed for comparison. |
| CyberPower EC650LCD | 650 VA / 390 W | Simulated sine | USB management | Not found | 3 years | Not found | Not sold through Dealectric; listed for comparison. |
| CyberPower CP685AVRG | 685 VA / 390 W | Simulated sine | USB and RS-232 | Not found | 3 years | Not found | Not sold through Dealectric; listed for comparison. |
| Eaton 5S 700 | 700 VA / 420 W | Not found | USB | 12 min at half load (retailer) | 2–3 years (sources differ) | Not found | Not sold through Dealectric; listed for comparison. |
| Tripp Lite AVR650UM | 650 VA / 325 W | Not found | USB | Not found | 3 years | Not found | Not sold through Dealectric; listed for comparison. |
Rows marked with a code and buy link are products Dealectric lists: the price was verified on the brand's own US store on 2026-11-07 and the code is tested daily in that brand's cart; the date shown is its last pass (last check 2026-11-13). The other rows (APC, CyberPower, Eaton, Tripp Lite, UGREEN) are included so the comparison is complete; their figures and prices were read from the makers' own US pages on 2026-11-03 and are not re-checked daily. The buy links are affiliate links: they open the brand's official US store at no cost to the shopper, and the commission pays for the testing; see the disclosure.
DC inline or AC box
UGREEN's DC UPS takes the NAS's own power brick as input (12 V 10 A, 19 V 7.9 A or 20 V 7 A), feeds the NAS from its four 18650 cells and reports over USB; there is no inverter and no switchover gap. It supports only UGREEN's DC-powered 2- and 4-bay NASync units (the 6- and 8-bay DXP6800 and DXP8800 use internal AC supplies and are listed as not supported), powers nothing else, and its battery replacement path is not published. An AC UPS backs up the NAS plus the router and switch, so the NAS stays reachable and NUT can share one UPS with several machines; it needs a model on your NAS's compatibility list for the USB shutdown to work, and its lead-acid battery lasts roughly three to five years.
What each NAS OS does
- UGOS Pro: detects a USB UPS under Control Panel → Hardware & Power → UPS, with Auto Shutdown (immediate, logged within two seconds in NASCompares' test), Timed shutdown and Standby (shut down before the battery is empty) modes, restart on power return, and a NUT server toggle. UGREEN's supported list names the US3000, APC BE600M1, APC BK650M2-CH and SANTAK TG-BOX850; other USB units may or may not be recognised.
- Synology DSM: USB, SNMP and network UPS with one NAS as server and others on an allow-list, plus a standby-mode trigger; Synology advises a real outage test.
- QNAP QTS: USB, SNMP and network master with up to 20 clients; QNAP suggests a 3–5 minute shutdown delay and keeps a per-model list.
- TrueNAS and Unraid: NUT; the US3000 needs manual configuration there, and one TrueNAS SCALE 25.10 user could not get NUT to see it.
Why bother
A NAS that loses power mid-write can leave a RAID array resyncing for hours or a file system to repair; the UPS's job is the clean shutdown, not hours of runtime. Ten minutes is enough if the shutdown is automatic; pick Auto Shutdown on UGOS, or a short delay on DSM and QTS, and test it by pulling the plug once.
Sources
- UGREEN NAS UPS US3000 — ai.ugreen.com
- UGREEN NAS UPS US2000 — ai.ugreen.com
- UGREEN: UPS for NAS buying and setup guide — ai.ugreen.com
- UGREEN support: supported UPS models — support.ugnas.com
- NASCompares: UGREEN US3000 review (UGOS modes, shutdown test) — nascompares.com
- rack2reality: UGREEN US3000 review (connection, runtime table) — rack2reality.com
- needtoknowit: UGREEN 120W UPS review (supported models) — www.needtoknowit.com.au
- TrueNAS forum: US3000 and NUT on TrueNAS SCALE — forums.truenas.com
- APC Back-UPS BE600M1 — www.se.com
- APC BE425M datasheet — www.mouser.com
- CyberPower CP850PFCLCD (CDW listing) — m.cdw.com
- Eaton 5S 700 (SHI listing) — www.shi.com
- Synology DSM: UPS settings — kb.synology.com
- QNAP: using a UPS with a QNAP NAS — www.qnap.com
Published 2026-11-03; figures for other brands read on 2026-11-03; our prices verified 2026-11-07. Corrections welcome at [email protected] or /feedback.