UPS/Inverter Run Time Calculator


How long can I run inverter/UPS on my batteries?

To estimate how long power batteries & inverter/UPS combination will run, please use this handy calculator.


1. Enter the voltage of your battery or bank of batteries. Battery Voltage
Battery Type Voltage Amp Hours
22 NF 12 50
24 NF 12 75
27 NF 12 100
8 D 12 200
2. Enter the total Amp/Hrs of the battery or bank of batteries. Amp/Hrs
3. Enter the combined Watt value of the appliances you plan to run from your battery. Watts
Examples Watts
19" Color TV 100
Circular Saw 1500
Computer System 300
Microwave Oven 1100
Power Drill 400
Toaster 1000
Represents actual power consumption as measured on sample products. Click below for Chart of Typical Appliance/Tool Usage

Click the Calculate button to see the number of hours your configuration should run.

hour(s) of operating time, approximate. Based on fully charged batteries.


Tip: deep cycle battery generally have the highest reserve rating, they are also capable of withstanding repeated dains of power and recharging, they should not be discharged below 50% charged state. Doing so will shorten life span of battery based on most battery manufacturers' recommendations.