UPS calculator hub → Scenario
UPS Runtime for NAS
Network-attached storage often runs 24/7 at modest steady watts. The decision is usually whether you can finish RAID sync and graceful shutdown before voltage collapse—not peak VA marketing.
Who this scenario is for
Best for: Home labs, Synology/QNAP users, and small business file servers on a dedicated online or line-interactive UPS.
Not ideal for: Whole-rack IT with mixed motor loads, or NAS units sharing a UPS with high-inrush laser printers.
Quick answer
Many NAS builds sit near 0.15 kW; on 48 V / 100 Ah with planning derates, screening math often exceeds one hour—still confirm disk shutdown policy and battery health.
Key variables
- Steady watts with disks spinning: Include all bays active and network switches if they share the protected feed.
- Target minutes vs. sync time: Match runtime to vendor guidance for safe shutdown during RAID resync or scrub operations.
- Online vs. standby topology: Online UPS paths add continuous inverter loss but cleaner output for sensitive electronics.
Example: light NAS load
0.15 kW on a 1 kVA frame with 48 V / 100 Ah commonly screens above 60 minutes before temperature and age derates—use measured draw from the NAS admin UI or a meter.
Next steps — tools
- UPS Runtime Calculator — minutes at your kW, V, and Ah.
- UPS Load Calculator — roll up devices before runtime.
- UPS Battery Calculator — Ah for a target minute goal.
- UPS Capacity Calculator — required kVA with PF and margin.
Assumptions and disclaimer
Figures on this page are planning estimates using typical efficiency (~0.8) and safety factor (~0.7). Battery age, temperature, discharge rate, and UPS topology change real minutes. Confirm procurement with manufacturer runtime charts and your licensed engineer where required.
Frequently asked questions
How long should a NAS UPS last?
Enough for graceful shutdown plus margin—often 15–60+ minutes depending on watts and Ah. Measure NAS draw, then run the runtime calculator.
Does Synology UPS support replace manual sizing?
USB signaling helps shutdown timing; you still need correct battery energy for the minutes you want before transfer.
Should the router share the NAS UPS?
If remote access during outages matters, include router and switch watts in load—or size them on a smaller dedicated unit.
Related UPS scenarios
Main UPS Runtime Calculator · How to calculate UPS runtime (guide)