Answer / ananth

T = N.V.X / VA

T= Time in Hours
N = No. of batteries
V= Voltage of Battery
X= Amp-Hour of the Battery
VA= Load

Answer / subir kumar manna

numbers of battery * ah of battery /output kva*130
34*200 /160*130
6800/20800
0.32 hours .

Answer / bhushan

UPS / Invertor Battery Backup Time =
----------------------------------


Batt Voltage X No.of (Batteries) X Ah (Single Battery) /
Total Load (Watts) = No.Hours Backup


Example :- 12v X 20(Batteries) X 200Ah (Single Battery)
/ 6000 (Watts) = No.Hours Backup


48000 / 6000 Watts = 8 Hours Backup

Answer / dhruvendra

V*AH/VA

Answer / a. dutta

To get one hour battery backup:

BATTERY AH = 1000 × VA × PF /( NO. OF BATTERY × BATTERY
VOLTAGE × LOAD% × PF

Answer / sayyed fayyaz ahmed

Calculating the UPS and Battery Backup Time
Before calculating the Battery Backup, let us know a few
factors that vary battery backup.
For and UPS with 875Va we can us a maximum load of 640
watts 677Va we can us a maximum load of 540 watts
The main thing we should understand is that whatever may be
the UPS wattage the battery backup will not vary.
The battery backup will only vary depending on the battery
Ah and the Usage Load.
To calculate UPS backup, we have a simple formula.
UPS Backup = Battery Ah * (Volts/Load) * (1/Power Factor)
Example: Let us calculate the backup for a system UPS
Load is the usage power, suppose we are running a PC then
the load is around 300 watts
Power Factor varies for device to device, the average power
factor is 1.4
Voltage is the voltage of the battery.
For a single battery the voltage is 12v.
If the batteries are connected in a series Voltage = 12 *
no. of batteries.
Battery Ah is the battery ampere used for the ups,
System UPS battery AH is 7
Then Battery Backup = 7 * (12/300) * (1/1.4)
= 7 * (0.04) * (0.7)
= 0.19 hours
= 11.4 Minutes
Note: You can use the same formula for calculating the
battery backup for home UPS or an INVERTER.

Answer / narayanarao.s

back up( in hours)= system dc volts x AH rating(
battery)/kva(load)x system power factor.

Answer / balajiram

Time=ups efficiency*battery efficiency*battery low volts*battery AH/ups output(watts)

Answer / prabhu

Battery Backup= No.of Batteries X Voltage of the batteries X Capacity of the batteries X Pf (0.8) / Load in Watts

Answer / prakash dhanshetty

backup time=(kva rating*power factor)!dc low of system

we use capister for power factor. when we use capaciter in dg circuit  than defect dg. can we use capaciter bank for dg circuit

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