Home Inverter & Battery Backup Hours Calculator

Determine the ideal inverter VA capacity (Luminous, Microtek, Exide) and tubular battery size for your home. Calculate total watt load and exact battery backup duration during power outages.

Interactive Home Inverter & Battery Backup Hours Calculator
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Formula & Calculation Methodology

Backup Hours = (Battery Ah * 12 Volts * 0.8 efficiency) / Total Connected Wattage Load.

Step-by-Step Worked Example

Load: 3 Fans (225W) + 5 LED Bulbs (75W) + 1 TV (100W) = 400W | Battery: 150Ah 12V

  1. Total Connected Wattage: 400 Watts
  2. Recommended Inverter Rating: 400W / 0.8 Power Factor = 500 VA -> 700-900 VA Inverter
  3. Battery Energy: 150Ah * 12V * 0.8 Efficiency = 1,440 Watt-Hours
  4. Backup Duration: 1,440 Wh / 400 W = 3.6 Hours
Result: Inverter: 900 VA | Backup Duration: 3.6 Hours continuous operation

Frequently Asked Questions

What is the power factor in inverter sizing?

Most residential inverters operate at a 0.8 power factor. To find required VA, divide total watts by 0.8 (e.g., 400 Watts / 0.8 = 500 VA).

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