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UPS Runtime for CCTV
Security systems need enough battery minutes to keep recording through brief outages and to shut down NVR storage cleanly on longer events.
Who this scenario is for
Best for: Installers and owners sizing UPS for PoE switches, cameras, and NVR on one protected branch.
Not ideal for: Municipal-scale surveillance with generator-first designs—those need formal electrical studies beyond this screening page.
Quick answer
Aggregate camera + NVR watts (often near 0.5 kW for small systems). Extra parallel battery strings buy minutes faster than oversizing kVA alone.
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 aging; derate expected minutes for wall-mounted enclosures in sun load.
Example: small CCTV plant
0.5 kW combined load on a 3 kVA UPS with 48 V / 100 Ah often screens near 45–60 minutes before derates—add strings if you must cover overnight outages without generator start.
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
Should PoE switches and NVR share one UPS?
Common for small sites. Sum their steady watts; avoid mixing high-inrush loads on the same branch.
How many minutes for security cameras?
Match site policy—often 30–120 minutes. Use measured load and battery Ah in the runtime calculator.
Do lithium UPS packs change CCTV runtime?
Chemistry affects discharge curves and vendor charts; still enter your measured kW and nameplate Ah for screening.
Related UPS scenarios
Main UPS Runtime Calculator · How to calculate UPS runtime (guide)