ToolHuts

Outils pratiques pour un travail de précision

Estimation d'Autonomie Onduleur pour Baie AV

Estimez l'autonomie à partir de la capacité totale du bloc de batteries et de la charge mesurée de la baie, en vérifiant les puissances nominales en watts et en VA de l'onduleur.

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.

Fonctionnement

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.

Exemple avec les saisies actuelles

Le résultat ci-dessus utilise exactement ces valeurs. Cet instantané est inclus à l’impression pour comparer la sortie aux mesures d’origine.

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

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

Avant d’utiliser le résultat

  • 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.

Limites

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.

Questions fréquentes

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.