How To Calculate The Back-Up Time of Your Inverter Batteries

Incase you want to calculate the back-up time of your batteries, there is a simple calculation for it. The right formula to us is

VDC * AH * PF / Load



VDC stands the volts of the direct current
AH stands for the amperes hour
P.F stands for power factor
Load stands for the summation of the total wattage of the load to be carried


Note that all batteries are 12volts but different AH

So if we have 5 12volts 200ah batteries with a load of 1280w, calculate the back up time

Solution

Given
VDC = 12 * 5 = 60v
P.F = 0.8
Load = 1280
Ah = 200ah

60 * 200* 0.8 / 1280 =7.5hours.