UPS battery 

Tips & techniques for UPS-Batteries


Luminous is all about innovating to perfection and ensuring complete benefit to consumers worldwide. The UPS is one such product by luminous that has been carefully crafted keeping in mind all the safety norms, aesthetic appeal, longevity and productivity. As we read further, we shall also learn about its other additional components, technical specifications with calculations that are equally important and play a huge role in making this product one of a kind.

Know your UPS
A power UPS or UPS is an electronic device or circuitry that changes direct current (DC) to alternating current (AC).The input voltage, output voltage and frequency and overall power handling depend on the design of the specific device or circuitry. The UPS does not produce any power; the power is provided by the DC source.A power UPS can be entirely electronic or may be a combination of mechanical effects (such as a rotary apparatus) and electronic circuitry.

Choosing the right UPS and battery for your homes entirely depends on your power requirement , the VA rating that is required based on the power requirement and battery that is suitable for the UPS. Once you know the total requirement , picking the right product just becomes easier.

Battery : The backbone of the UPS
The battery is the most important component of the UPS. It is responsible for the good performance and long life of your UPS.Therefore regular maintenance and care of the battery is very crucial. Just like any other home appliance, your UPS and its battery require regular maintenance for effective operation and longer life.Although they do not beautify your home like your steel coating double door refrigerator or your black shiny microwave, they do help you live comfortably in the most difficult time during power cuts.

Some maintenance tips to ensure proper efficiency of the UPS:

  • Battery placement: Always use a well ventilated area for UPS installation. The UPS battery gets heated up during charging and operation. An airy place reduces the heating up of the battery.It also reduces the frequent water topping requirement.
  • Battery usage: After installation use battery on a regular basis. If the power cut does not occur, discharge the battery completely once every month and then recharge it.
  • Water level check: Check the water level of battery every two months. Ensure that the water level is maintained between the maximum and minimum water limit. Always top up the battery with distilled water. Do not use tap water or rainwater as it contains excess minerals and impurities which affect the life and performance of the battery.
  • Cleanliness: Always keep the surface and sides of battery clean and dust free. Use cotton cloth to clean these surfaces
  • Protection from rusting: Keep the battery terminals corrosion free and rust free. If the terminals get corroded pour hot water + baking soda solution on the corrosive area or use a toothbrush for cleaning. This will remove the corrosion.Once the terminals become corrosion free, apply petroleum jelly or Vaseline on to the terminals, nuts and bolts to avoid future corrosion. Rusting and corrosion are very bad for battery performance. Rusting in terminals reduces the current flow to and from from the battery. This restricted flow of current results in slow battery charging which ultimately reduces battery life.
  • Open vents: Be careful that the vents around battery are dust free and open. Blocked vents lead to hydrogen gas accumulation which may lead to bursting of battery.
  • Safe installation:From safety point of view, install the UPS at safe places in your home which is out of the reach of children or a less used area. But at the same time make sure that it is airy and properly ventilated.
  • Battery replacement: Replace your battery if it is dead or damaged. Regular inspection will keep you updated on your UPS and battery conditions.

Tech Specs

Calculate size of UPS and battery bank
It is simple to calculate the size of the required UPS in proportion to the battery bank depending on the electrical load of any given space
Electrical Load detail:

  • 2 No of 60W,230V, 0.8 P.F Fan.
  • 1 No of 200W,230V, 0.8 P.F Computer.
  • 2 No of 30W,230V, 0.8 P.F Tube Light.

UPS / Battery Detail:

  • Additional Further Load Expansion (Af)=20%
  • Efficiency of UPS (Ie) = 80%
  • Required Battery Backup (Bb) = 2 Hours.
  • Battery Bank Voltage = 24V DC
  • Loose Connection/Wire Loss Factor (LF) = 20%
  • Battery Efficiency (n) = 90%
  • Battery Aging Factor (Ag) =20%
  • Depth of Discharge (DOD) =50%
  • Battery Operating Temp =46ºC
Calculation

Step 1: Calculate Total Load:
Fan Load= No x Watt =2×60=120 Watt
Fan Load=(No x Watt)/P.F=(2×60)/0.8= 150VA
Computer Load= No x Watt =1×200= 200 Watt
Computer Load=(No x Watt)/P.F =(1×200)/0.8= 250VA
Tube Light Load= No x Watt =2×30= 60 Watt
Tube Light Load=(No x Watt)/P.F =(2×30)/0.8= 75VA
Total Electrical Load=120+200+60 = 380 Watt
Total Electrical Load=150+250+75= 475VA

Step 2: Size of UPS:
Size of UPS =Total Load+(1+Af) / Ie VA
Size of UPS = 475+(1+20%) / 80%
Size of UPS = 712 VA

Step 3: Size of Battery:
Total Load of Battery Bank= (Total Load x Backup Capacity) / Battery Bank Volt
Total Load of Battery Bank=(380 x 2) / 24 Amp Hr
Total Load of Battery Bank= 32.66 Amp Hr
Temperature Correction Factor for 46ºC (Tp)=1
Size of Battery Bank=[ (Load) x (1+LF) x (1+Ag) x Tp] / [n x DOD] Amp/Hr
Size of Battery Bank= (32.66 x (1+20%) x (1+20%) x 1) / (90% x 50%)
Size of Battery Bank= 101.3 Amp/Hr

Step 4: Connection of Battery:
If We Select 120 Amp Hr , 12V DC Battery for Battery Bank:

  • Series Connection:

Series configurations will add the voltage of the two batteries but keep the amperage rating (Amp Hours) same.

  • Condition-I :

Selection of Battery for Voltage = Volt of Each Battery <= Volt of Battery Bank
Selection of Battery for Voltage =12< 24
Condition-I is O.K
No of Battery for Voltage = Volt of Battery Bank / Volt of Each Battery
No of Battery for Voltage =24/12 = 2 No’s

  • Condition-II :

Selection of Battery for Amp Hr = Amp Hr of Battery Bank <= Amp Hr of Each Battery
Selection of Battery for Amp Hr =3<=120
Condition-II is O.K
We can use Series Connection for Battery & No of Battery required 2 No’s

  • Parallel Configuration:

In Parallel connection, the current rating will increase but the voltage will be the same.
More the number of batteries more will be the amp/hour. Two batteries will produce twice the amp/hour of a single battery.

  • Condition-I :

Selection of Battery for Amp Hr = Amp Hr of Battery Bank / Amp Hr of Each Battery <=1
Selection of Battery for Amp Hr =101/120 = 0.84=1 No’s
Condition-I is O.K

  • Condition-II :

Selection of Battery for Voltage = Volt of Battery Bank = Volt of Each Battery
Condition-II :Selection of Battery for Voltage for Amp Hr = 24<=12
Condition-II is Not Full Fill
We cannot use Parallel Connection for Battery as per our requirement But If We do Practically It is Possible and it will give more Hours of back

  • Parallel Configuration
  • Condition-I :

Selection of Battery for Amp Hr = Amp Hr of Battery Bank / Amp Hr of Each Battery <=1
Selection of Battery for Amp Hr =101/60 = 1.63=1 No’s
Condition-I is O.K

  • Condition-II :

Selection of Battery for Voltage = Volt of Battery Bank = Volt of Each Battery
Condition-II :Selection of Battery for Voltage for Amp Hr = 24=12
Condition-II is Not Full Fill
We cannot use Parallel Connection for Battery as per our requirement.

  • Series-Parallel Connection:
  • Condition-I :

Selection of Battery for Amp Hr = Amp Hr of Each Battery <= Amp Hr of Battery Bank
Selection of Battery for Amp Hr =120<=60
Condition-I is OK
No of Battery for Amp Hr = Amp Hr of Battery Bank / Amp Hr of Each Battery
No of Battery for Amp Hr = 120/60 =1.68 =2 No’s

  • Condition-II :

Selection of Battery for Voltage = Volt of Each Battery <= Volt of Battery Bank
Selection of Battery for Voltage = 12<=24
Condition-II is OK
No of Battery for Voltage = Volt of Battery Bank / Volt of Each Battery
No of Battery for Voltage = 24 / 12 =2 No’s
No of Battery Required = No of Battery Amp Hr x No of Battery for Voltage
No of Battery Required = 2 x 2= 4 No’s
We can use Series-Parallel Connection for Battery

  • Summary:

Total Electrical Load= 380 Watt
Total Electrical Load= 475VA
Size of UPS = 712 VA
Size of Battery Bank= 101.3 Amp/Hr
For 120 Amp/Hr , 12V DC Battery : Series Connection & 2 No’s of Battery or
For 60 Amp/Hr , 12V DC Battery : Series-Parallel Connection & 4 No’s of Battery

Defining our requirements and understanding the specifications of our homes is the first step in making that right choice of UPS and batteries. However, in many situations, not enough care is taken in establishing correct requirements up front.This causes problems and we end up buying the wrong product and spend more time and money in fixing several ambiguities. Therefore, it is necessary that requirements are established in a systematic way to ensure complete accuracy and comfort.