Emergency Backup Power Calculator

Size your home backup power system for emergencies and power outages.
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Plan Emergency Backup System

How long do you need backup power? (24h = 1 day, 72h = 3 days)

Select Critical Devices

Choose devices you need to keep running during a power outage

How Emergency Backup is Calculated

Total Wh Formula: Sum of (Device Watts × Hours × Quantity)

Recommended Capacity: Total Wh × 1.25 (25% safety margin)

Output Wattage: Sum of all devices running simultaneously

The 25% buffer ensures you have enough power even with efficiency losses and ensures the battery isn't fully depleted (which shortens battery life).

Important Safety Notes

  • Medical devices: If you depend on life-critical medical equipment, consult with your doctor and power company about backup solutions
  • Carbon monoxide: NEVER run gas generators indoors or in garages - they produce deadly carbon monoxide
  • Refrigerated medicine: Ensure critical medications stay at proper temperature
  • Water supply: If you have a well pump, factor in its power requirements
  • Heating/cooling: Space heaters and AC units use significant power - consider alternatives
  • Battery maintenance: Keep your backup system charged and test it quarterly

Emergency Preparedness Tips

  • Keep it charged: Maintain your power station at 50-80% charge when not in use
  • Solar backup: Pair with solar panels to recharge during extended outages
  • Prioritize devices: Start with most critical (medical, fridge) and add others as capacity allows
  • LED lights only: Use LED bulbs (10W) instead of incandescent (60W+)
  • Minimize fridge opening: A closed fridge stays cold for 4 hours, freezer for 24-48 hours
  • Have a plan: Know which devices to power first and practice using your system