Energy - PowerFree

Inverter Battery Runtime Calculator

Calculate how long your inverter battery will last based on the connected load and battery capacity.

Enter Values

Result

Enter values above and click Calculate to see your result.

AI Assistant

Ask about this calculator

I can help you understand the inverter battery runtime calculator formula, interpret your results, and answer follow-up questions.

Try asking

Formula

Runtime = (Battery Ah × Voltage × Efficiency) ÷ Load (Watts)

Converts chemical energy capacity to watt-hours and divides by the power demand, adjusting for conversion losses.

Worked Example

A 200Ah 12V battery with 80% efficiency powering a 100W load lasts about 19 hours.

Maximizing Battery Life

Understanding runtime helps in managing critical loads during outages.
  • Turn off non-essential appliances to extend runtime.
  • Temperature affects battery capacity; keep them in a cool area.
  • Lithium batteries offer higher usable capacity than lead-acid.

Regularly test your batteries to ensure they hold the expected charge.

You can also calculate changes using our Battery Backup Calculator or Inverter Load Calculator.

Frequently Asked Questions

Why 80% efficiency?

Inverters lose energy as heat during the DC to AC conversion process.

Can I discharge a lead-acid battery to 0%?

No, it significantly shortens life. This calculation assumes full capacity for simplicity, but 50% is recommended for lead-acid.

Secure and Private

All calculations run locally. Your data never leaves your browser.

Precise Calculations Powered by Calculory AI