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Question
How to calculate the ups battery back up? give the formula.
 Question Submitted By :: Electrical-Engineering
I also faced this Question!!     Answer Posted By  
 
Answer
# 1
numbers of battery * ah of battery /output kva*130
34*200 /160*130
6800/20800
0.32 hours .
 
Is This Answer Correct ?    54 Yes 22 No
Subir Kumar Manna
 
Answer
# 2
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
 
Is This Answer Correct ?    38 Yes 7 No
Ananth
 
 
 
Answer
# 3
V*AH/VA 
Is This Answer Correct ?    28 Yes 15 No
Dhruvendra
 
Answer
# 4
To get one hour battery backup:

BATTERY AH = 1000 VA PF /( NO. OF BATTERY BATTERY
VOLTAGE LOAD% PF
 
Is This Answer Correct ?    4 Yes 0 No
A. Dutta
 
Answer
# 5
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.
 
Is This Answer Correct ?    3 Yes 0 No
Sayyed Fayyaz Ahmed
 
Answer
# 6
Time=ups efficiency*battery efficiency*battery low volts*battery AH/ups output(watts) 
Is This Answer Correct ?    8 Yes 6 No
Balajiram
 
Answer
# 7
backup formula= KVA/DC LOW *POWER FACTOR

FOR EX:2 KVA/120 DC VOLT(SYSTEM VOLT)OUR MAINTAINED POWER

FACTOR (0.8 P.F),PER BATTERY=12V(DC LOW=10.8),HERE USING THE

SYSTEM VOLT=120V SO,10 BATTERIES-10*12=120V


DERIVATION : 2000/108*0.8

AH=14.81(APP.17 AH BATTERY) given 30 minutes backup
 
Is This Answer Correct ?    6 Yes 5 No
Sathiyanarayanan
 
Answer
# 8
back up( in hours)= system dc volts x AH rating(
battery)/kva(load)x system power factor.
 
Is This Answer Correct ?    1 Yes 0 No
Narayanarao.s
 
Answer
# 9
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
 
Is This Answer Correct ?    2 Yes 1 No
Bhushan
 
Answer
# 10
backup time=(kva rating*power factor)!dc low of system 
Is This Answer Correct ?    3 Yes 3 No
Prakash Dhanshetty
 

 
 
 
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