How to Calculate Your UPS's Back-up Time?

2022-07-04 11:39

The UPS backup time depends on the efficiency of the UPS, the power of the load, and the battery capacity. However, you can easily calculate the accurate battery backup time with a simple formula or use a battery backup calculator. Backup Time (in hours) = Battery Capacity (Ah) X Input voltage (V) X UPS Efficiency (%) X Discharging Rate (%) / Total Load (Watt)

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Let us assume that you have an UPS with 2 pcs of 12V/9 Ah batteries and 60% discharging rate, 80% efficiency. You want 3 tube lights, 2 fans, and 1 Wi-Fi router to run on that battery. So, what will be your UPS battery backup time, and how long will your appliances run in this specific case?

3 tube lights = 40 x 3 = 120 Watts

2 fans = 75 x 2 = 150 Watts

1 Wi-Fi router = 1×20 Watts = 20 Watts

So, the total load in your case is 120 + 150 + 20 = 290 Watts.

Now, let us apply all these values in the above-said battery backup time formula.

Backup Time (in hours) = 2 x 9 x 12 x 0.8 x 0.6 / 290 = 0.36

Therefore, the UPS will continue to supply power for about 21 minutes in this case. Please note that this data is only theoretical reference. In the actual scene, due to the limitations of various factors, the backup time often has certain errors. The efficiency of UPS plays a crucial role in its backup time. The higher ups efficiency, the longer backup time.

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