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What Size UPS Do You Need for 16 PoE Security Cameras?

Plan UPS output capacity and runtime for sixteen PoE cameras, NVRs, network switches and internet gear with realistic nighttime power draw.

Updated September 13, 2026 · SecurityVerdicts research desk

Sixteen-camera systems can move from a small UPS problem to a genuine power-design problem because the PoE camera load alone may exceed 100W. Add the recorder, switch electronics and network gear and a compact desktop UPS may provide far less runtime than expected.

Worked example

Component	Example load
14 fixed cameras × 8W	112W
2 higher-draw cameras × 18W	36W
PoE switch electronics	20W
NVR	30W
Router + modem/ONT	20W
Total	218W

Applying roughly 20–25% output headroom puts the UPS output target comfortably above about 260–275W. Runtime then has to be checked against the manufacturer curve at roughly the real 218W load.

Nighttime can be the worst case

Infrared LEDs, white-light deterrence and heaters can increase camera power after dark. A switch that reports 140W during the day may jump when every camera switches modes simultaneously. Size the UPS and the PoE switch from maximum or measured worst-case draw rather than a calm daytime average.

One large UPS or two?

Splitting the system can improve fault isolation. One UPS might protect half the cameras and one switch while a second protects the other camera group plus NVR/network gear. The tradeoff is more batteries to maintain and more complex runtime planning.

Do not confuse PoE budget with UPS budget

The PoE switch must be able to deliver the camera watts. The UPS must power the switch's AC input, including switch losses and its own electronics. The two budgets are related but not identical.

Design principle: decide how many minutes of recording you actually need. A 10-minute bridge for short utility interruptions is a very different purchase from two hours of surveillance continuity.