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Inverter Battery Backup Calculator

Using this result: Calculates estimated runtime based on battery capacity and continuous wattage load, factoring in inverter conversion efficiency and depth of discharge.

Category: Home & Solar · How to check a result

Calculate estimated battery runtime hours from battery amp-hour capacity, voltage, and connected load.

Instant browser calculation Transparent formula No registration needed 100% free utility

Total Battery Capacity (Ah)

System Voltage (V - e.g. 12, 24, 48)

Total Active Load (Watts)

Usable Depth of Discharge % (50% Lead-Acid, 85% Lithium)

Your result

Enter your parameters and click Calculate.

FASTRuns directly in your browser

CLEARTransparent step-by-step logic

PRIVATENo server data storage

How this calculation works

Calculates runtime by multiplying Amp-hours by battery voltage to find total nominal energy, applies the safe Depth of Discharge (DoD) to protect battery longevity (typically 50% for lead-acid/tubular, 80-90% for lithium LiFePO4), applies an 85% inverter efficiency factor, and divides by running watts.

Practical worked example

A 12V 200Ah tubular battery running a 350W load at 50% DoD provides approximately 2 hours and 55 minutes of continuous power.

Important considerations & limitations

Actual runtime decreases if inductive loads (fridges, fans) cause voltage dips, or if battery temperature deviates from 25°C.

About the Inverter Battery Backup Calculator

The Inverter Battery Backup Calculator on naijaloyal.com.ng is an interactive tool created to help households and businesses plan inverter battery backups accurately during power outages.

Using results for planning

When modeling backup times, test both peak load scenarios (all lights and appliances active) and conservative base load scenarios to understand total runtime flexibility.