UPS applications → Scenario
UPS for CCTV Systems: Sizing, Runtime & Battery Requirements
Plan battery backup for IP cameras, PoE switches, and NVR/DVR recorders: estimate total load, pick a UPS size, then verify backup minutes before procurement.
Who this scenario is for
Best for: Installers and owners sizing UPS for PoE security camera systems, network video recorders, and small-to-mid CCTV plants on one protected branch.
Not ideal for: City-wide surveillance with generator-first designs or stamped electrical studies—use formal engineering beyond this screening guide.
Quick answer
Sum IP camera, PoE switch, and NVR watts (many 4–8 camera sites land near 0.1–0.3 kW). Size UPS kVA with power factor headroom, then add battery Ah—or parallel strings—for your required backup minutes.
How much power does a CCTV system use?
PoE class limits on a switch datasheet are not the same as measured draw. Budget per camera, add switch overhead, and include the recorder and any uplink router on the protected feed.
| Device | Typical power | Notes |
|---|---|---|
| IP camera (non-PoE, local adapter) | 6–10 W | Fixed dome, no IR heaters |
| PoE IP camera | 8–15 W | Higher with IR or motorised PTZ |
| PoE+ / high-power camera | 15–25 W | Long-range IR, heaters, PTZ |
| NVR (4–16 channel) | 25–60 W | Add storage bays and fans |
| DVR (legacy coax) | 20–45 W | Cameras powered separately |
| PoE switch (8-port) | 15–25 W | Excludes delivered PoE to cameras |
| PoE switch (24-port, partial load) | 40–80 W | Scale with active ports |
Last reviewed: June 2025. Values are planning estimates—meter each channel where possible.
Example: 4, 8, and 16 camera systems
| System | Cameras | NVR | PoE switch | Total (approx.) |
|---|---|---|---|---|
| 4-camera site | 4 × 12 W = 48 W | 30 W | 20 W | ~98 W |
| 8-camera site | 8 × 12 W = 96 W | 40 W | 35 W | ~171 W |
| 16-camera site | 16 × 12 W = 192 W | 55 W | 60 W | ~307 W |
Convert total W to kW (÷ 1000), then use the UPS Capacity Calculator for kVA with your site power factor—typically 0.8–0.9 for mixed IT/CCTV loads.
UPS size for CCTV loads (screening chart)
Line-interactive UPS frames with ~25–35% headroom above real kW. Confirm binding procurement with manufacturer charts.
| Total load | Screening UPS (VA / W) | Typical use |
|---|---|---|
| ~100 W (0.1 kW) | 650 VA / 400 W | 4-camera + NVR closet |
| ~200 W (0.2 kW) | 1000 VA / 600–700 W | 8-camera small office |
| ~350 W (0.35 kW) | 1500 VA / 900–1050 W | 16-camera retail / warehouse edge |
| ~500 W (0.5 kW) | 3000 VA / 2100 W | Multi-switch plant or PTZ-heavy site |
Recommended backup time for CCTV
- 15 minutes: Graceful NVR shutdown and brief blips—minimum for unattended recorders.
- 30 minutes: Common retail / office policy; covers most utility reclosers.
- 60 minutes: Sites without generators that must keep recording through longer outages.
- 120+ minutes: Remote sites, gate security, or until manual generator start—size extra battery strings.
Match minutes to site policy first, then enter load and Ah in the UPS Battery Calculator and verify in the runtime tool below.
Key variables
- PoE budget vs. measured draw: Switch PoE class limits differ from real camera consumption—sum per-channel measurements when possible.
- Required recording window: Define minimum minutes of continued recording during outages before intentional shutdown.
- Outdoor cabinet temperature: Heat accelerates battery aging; derate expected minutes for wall-mounted enclosures in sun load.
- Night / IR load: Infrared illumination can add 2–5 W per camera versus daytime steady draw.
UPS battery sizing for CCTV
Battery minutes scale with usable Ah at your system voltage, UPS efficiency (~0.8 screening), and safety factor (~0.7 for aged cells). Parallel strings increase Ah when the UPS supports them.
Example: 0.17 kW (8-camera plant) on a 1 kVA UPS with 48 V / 100 Ah often screens near 45–75 minutes before temperature and age derates—add a second string if policy requires 120 minutes.
Workflow: Load → Capacity → Battery Ah → runtime calculator in the next section.
Runtime calculator — verify your CCTV plant
Enter measured kW, UPS kVA, power factor, battery voltage, Ah, and string count. Default preset reflects a ~0.5 kW multi-switch CCTV plant for quick screening.
Use UPS Runtime Calculator (CCTV preset)
See also: How to calculate UPS runtime · UPS battery sizing guide · Choosing a UPS system
Next steps — tools
- UPS Load Calculator — roll up cameras, switch, and NVR watts.
- UPS Capacity Calculator — required kVA with PF and margin.
- UPS Battery Calculator — Ah for a target minute goal.
- UPS Runtime Calculator — minutes at your kW, V, and Ah.
- How long will UPS last? — guided entry across the UPS tool chain.
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. VA recommendations are screening ranges, not product endorsements. Confirm procurement with manufacturer runtime charts and your licensed engineer where required.
Frequently asked questions
What size UPS for 8 cameras?
Screen roughly 150–250 W total load (8 PoE cameras + NVR + switch). A 1000 VA / 650 W line-interactive UPS with ~30% headroom is a common starting point—confirm with measured watts and your target backup minutes.
Can a UPS power a PoE switch?
Yes—PoE switches are often the largest steady load in small CCTV plants. Include switch PoE budget and any uplink gear on the same protected branch when sizing VA and battery Ah.
How long should CCTV stay online during an outage?
Many sites target 30–120 minutes so recording continues through brief outages. Critical sites or those without generators may need several hours—size battery Ah to your policy, not a generic default.
What battery Ah is required for 60 minutes of CCTV backup?
Depends on total kW, battery voltage, string count, UPS efficiency, and age derate. Use the UPS Battery Calculator for Ah from load and minutes, then verify minutes in the Runtime Calculator with your nameplate values.
Should NVR and cameras share one UPS?
Common for small installs: one UPS feeds PoE switch, cameras, and NVR. Sum steady watts; avoid mixing high-inrush loads (motors, large HVAC) on the same branch.
How much power does a 4-camera CCTV system consume?
Typical screening: 4 × 12 W PoE cameras (48 W) + 30 W NVR + 20 W PoE switch ≈ 98 W (0.1 kW). Night IR and heater-equipped outdoor cameras can run higher—measure per channel when possible.
What UPS works for outdoor CCTV cabinets?
Choose a temperature-rated enclosure and derate battery minutes for heat. Lithium packs tolerate wider temperature swings than VRLA in many cabinets—still follow the manufacturer chart for your ambient range.
UPS vs generator for CCTV — which is better?
UPS bridges seconds-to-minutes instantly; generators cover long outages but need start time. Many sites use UPS for ride-through and recording continuity, plus a generator for extended events.
Can I use inverter batteries for CCTV UPS?
Only when the UPS or external battery cabinet is designed for that chemistry and BMS. Do not substitute automotive or inverter cells on a VRLA-rated string without an engineer-approved plan.
Do I need online or line-interactive UPS for NVR recording?
Line-interactive UPS units cover most small CCTV sites. Online double-conversion helps when input power is noisy or sag-heavy; either type must be sized on real kW, not VA nameplate alone.
Often planned together
- UPS for network closet — PoE switches at remote sites
- UPS for server rack — Rack-mounted NVR or larger recorders
Related UPS scenarios
UPS applications on hub · How long will UPS last? · UPS Runtime Calculator · Runtime calculation guide · Battery sizing guide