UPS Backup Time Calculator
Find out how long your UPS or battery will last during a load-shedding break. Enter battery capacity, voltage, number of batteries and your load in watts to get an estimated backup time in hours, computed instantly and free.
Add load by clicking the chips below:
Backup Time
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Usable Energy
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Note: Actual backup also depends on the battery age and health. An old battery will give less backup.
How to use
- Enter the battery Ah (written on the label, e.g. 200Ah), voltage and number of batteries.
- Add the watts of the things you want to run — click the chips or type the total load yourself.
- The result will update instantly: backup time (hours + minutes) and usable watt-hours.
Formula: Usable Wh = Ah × V × Batteries × Efficiency ÷ 100. Backup hours = Usable Wh ÷ Load (W). For UPS, battery or solar work: Azlaan Electric AC Solar Center, Faisalabad — 0300-8987448.
Good to know
- Real backup time is usually less than the estimate — old batteries lose capacity.
- Add up all connected watts (fan, lights, router) for an honest load figure.
- Heavy loads like motors and irons drain batteries much faster than LED lights and fans.
- If the result is too short, adding one more battery of the same voltage helps.