Find Your System
Backup Runtime Calculator
Estimate how long your battery can run selected loads.
Calculator
Enter battery capacity, usable capacity, load power, and inverter efficiency to estimate backup runtime.
Quick battery size
Runtime = Usable Battery Capacity ÷ Total Load Power
Runtime Examples
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10kWh Battery Runtime
WiFi / Lights / POS / Refrigerator / Small office loads
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20kWh Battery Runtime
Home backup / Freezer / Small business backup / Longer outage protection
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50kWh Battery Runtime
Commercial backup power / Refrigeration / Pump loads / Warehouse loads
Load Runtime Guide
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Low Loads
WiFi / LED lights / Laptop / POS
Longer runtime
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Medium Loads
Refrigerator / Freezer / Office equipment / Security system
Medium runtime
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High Loads
Cold room / Pump / Air conditioner / Compressor
Shorter runtime, starting current must be checked
Upgrade Options
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Basic Backup
Choose 10kWh Battery
View option -
Longer Backup
Choose 15kWh Battery or 20kWh Battery
View option -
Refrigeration or Pumps
Choose 30kWh Battery or 50kWh Battery
View option -
Commercial Runtime
Choose Commercial Battery Storage
View option
Recommended Products
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10kWh Battery
- Capacity
- 10kWh
- Recommended For
- WiFi / Lights / POS / Refrigerator
- System Fit
- Basic backup runtime
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15kWh Battery
- Capacity
- 15kWh
- Recommended For
- Home backup / Office backup / Longer essential loads
- System Fit
- Extended backup runtime
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20kWh Battery
- Capacity
- 20kWh
- Recommended For
- Freezer / Small business / Longer outage protection
- System Fit
- Home and business battery backup
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30kWh Battery
- Capacity
- 30kWh
- Recommended For
- Pump loads / Solar battery backup / More runtime
- System Fit
- Medium backup battery runtime
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50kWh Battery
- Capacity
- 50kWh
- Recommended For
- Commercial loads / Refrigeration / Warehouse / Pump backup
- System Fit
- Commercial backup runtime
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Commercial Battery Storage
- Capacity
- Project-Based
- Recommended For
- Business backup / Solar storage / Long runtime needs
- System Fit
- Commercial battery backup system
Project Videos
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Battery Runtime Test
Test Loads: Lights / WiFi / Refrigerator
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Refrigerator Backup Test
Test Loads: Refrigerator / Freezer
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POS Backup Power Test
Test Loads: POS / WiFi / Lights / Cash register
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Commercial Battery Installation
Test Loads: Refrigeration / Office loads / Security
FAQ
How long will a battery backup last?
Runtime depends on battery capacity, usable energy, load power, inverter efficiency, and load changes.
How do I calculate battery runtime?
Use battery capacity and total load power. This tool estimates backup time from usable kWh and connected load.
Is this the same as a UPS battery backup runtime calculator?
No. This battery backup time calculator is for kWh battery backup systems. Small UPS units may use different battery ratings and runtime curves.
Why is the real runtime shorter than the calculator result?
Real runtime can be shorter when loads increase, motors start, inverter efficiency drops, or the battery does not use its full rated capacity.
Can a 10kWh Battery run a refrigerator?
Yes, when the refrigerator load and starting current match the inverter output.
Is a 20kWh Battery enough for home backup?
Yes for many essential loads. Air conditioning, pumps, heating, and large appliances need separate checks.
What size battery do I need for POS, WiFi, and lights?
POS, WiFi, lights, and cash registers often fit smaller systems. Final runtime depends on total wattage and target backup hours.
Can a battery run freezers or cold rooms?
Yes, but freezers, cold rooms, compressors, and refrigeration systems need inverter output and starting current checks.
What information do you need to size my backup system?
Load list, wattage, target backup hours, inverter model, solar system size, and installation site details.