ToolHuts

Herramientas prácticas para trabajos de precisión

Estimación de Autonomía del SAI para Racks AV

Estime la autonomía a partir de la capacidad total del banco de baterías y la carga medida del rack, comprobando tanto los vatios como los VA nominales del SAI.

VA
W
V

Use the voltage of the complete battery string, not one battery.

Ah

Series batteries add voltage, not amp-hour capacity.

W
%
%
W
Estimated runtime under entered assumptions20minutes
Within VA and watt ratingsYes
Watt load38.9%
VA load25.9%
Nominal pack energy216Wh
Usable output energy119Wh
Estimated pack current17.9A

Check both VA and watt ratings. Runtime uses the entered derating and a linear energy model; the UPS manufacturer's runtime chart is more authoritative when available.

Cómo funciona

What to enter: copy both UPS ratings and the total voltage and amp-hour capacity of the complete battery pack. Measure the rack load if possible, then use conservative loss factors.

Calculation. Runtime = pack voltage × pack amp-hours × usable fraction × efficiency ÷ (load + UPS idle draw).

Example. A 24 V, 9 Ah pack contains 216 nominal Wh before discharge-rate, age and conversion losses.

Ejemplo con los datos actuales

El resultado anterior utiliza exactamente estos valores. Esta captura se incluye al imprimir para cotejar la salida con las medidas originales.

UPS VA rating
1500 VA
UPS watt rating
900 W
Total battery-pack voltage
24 V
Pack capacity at that voltage
9 Ah
Measured AV rack load
350 W
Load power factor
0.9
Inverter efficiency
85 %
Usable battery capacity
65 %
UPS internal draw
15 W

Resultado principal: Estimated runtime under entered assumptions: 20 minutes.

Antes de usar el resultado

  • Measure from the datum or reference edge described by this tool, and do not mix inside, outside and centerline dimensions.
  • Keep inputs in the displayed units and preserve more precision than the final cutting or purchasing tolerance requires.
  • When the result is close to a limit, verify it with a test piece, field measurement, manufacturer drawing or qualified project professional.

Limitaciones

Real UPS runtime is non-linear. Discharge rate, chemistry, age, temperature, inverter cut-off, startup surge and firmware matter. Confirm the pack specification and use the manufacturer runtime chart for safety-critical loads.

Preguntas frecuentes

Why can this estimate exceed the UPS runtime chart?

The usable-capacity factor may be too optimistic. Small lead-acid packs deliver less rated capacity at high current, and ageing reduces it further.