How do I calculate how long a UPS will last?

UPS runtime = (Battery Capacity in Ah × Battery Voltage × Power Factor × Efficiency) ÷ Load in Watts. Use the ExTell Systems UPS Runtime Calculator at extellsystems.com/ups-calculator for a quick automated estimate.

How long will a 1kVA UPS run with a 500W load?

A 1 kVA UPS (typically 700–800W usable) with standard 7Ah batteries will run approximately 5–10 minutes at 500W load. Adding external battery packs can extend this to 30+ minutes.

What is the formula for UPS battery runtime?

Approximate UPS runtime (hours) = (Battery Ah × Voltage × 0.8 efficiency) ÷ Load in Watts. For example: (100Ah × 48V × 0.8) ÷ 500W = 7.68 hours.

How many watts can a 1000VA UPS handle?

A 1000 VA UPS with a 0.8 power factor can handle up to 800 watts of connected load. Exceeding this rating will cause the UPS to alarm or shut down.

Can I connect a generator to a UPS?

Yes, many ExTell Systems UPS models support generator compatibility mode. This adjusts the input voltage/frequency tolerance to accept the variable output typical of diesel generators. Check your UPS model specifications or contact support@extellsystems.com.

UPS Runtime Calculator — Estimate Battery Backup | ExTell Systems

UPS Runtime Calculator

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