Inverter Battery Backup Calculator

About the Calculator

The Inverter Battery Backup Calculator helps you determine how long your inverter or UPS battery will last during a power outage. By inputting your battery's capacity (in Amp-hours), voltage (in Volts), efficiency (in percentage), and the total connected load (in Watts), the calculator provides an accurate estimate of backup time in hours. This tool is ideal for homeowners, businesses, or anyone planning a reliable power backup system. The formula used is:

Backup Time (hours) = (Battery Capacity × Battery Voltage × Battery Efficiency / 100) / Connected Load

How to Use the Calculator

Enter the battery capacity in Amp-hours (Ah), typically found on the battery label (e.g., 150 Ah).
Input the battery voltage in Volts (V), usually 12V, 24V, or 48V for inverters.
Specify the battery efficiency as a percentage (default is 90%). This accounts for energy losses.
Enter the connected load in Watts (W), which is the total power consumption of devices connected to the inverter.
Click the Calculate button to see the estimated backup time in hours.
Use the Reset button to clear all inputs and start over.

Example: For a 150Ah battery at 12V with 90% efficiency and a 400W load, the backup time is approximately 4.05 hours.