Things to Keep in mind before buying an inverter

Buying Guide 305 comments

Boiling summer is just few weeks ahead, scheduled and unscheduled power cuts are expected as usual. Inverters are one of the most demanded products of summer season. Are you planning to buy or upgrade your inverter in this season? Then instead of being trapped in the marketing gimmicks, understand some basic facts and do a little bit home work. Here some facts you must know before buying an inverter

inverter thumb Things to Keep in mind before buying an inverterCalculate your power requirements

Before going to purchase an inverter- You have to make a rough estimation of your power requirements. remember- Inverter is not a Generator. Inverter has it’s own limitations. You can’t power and run your complete home with a normal inverter. If your power requirement is  more than 3000 VA, then an inverter alone can’t cater your demands effectively. No doubt a high power inverter can run your refrigerator and air conditioners, but how long?  Here your battery will not last more than few hours. Hence it it better to go for a home generator. However if you don’t want a single minute power downtime, then a power inverter – electric generator combination is a good option.

 Wattage rating of typical home appliances

Appliances  Power
Fan (Ceiling) 50-75 Watts
Fan (Table) 25-50 Watts
CFL 18 Watts 18 Watts
Computer (Desktop) 80- 150 Watts
Laptop 20- 75 Watts
LCD TV (32”) 150 Watts
Refrigerator 160 – 250 Watts
Tube Light (4 Feet) 40 Watts

Starting power and running power

Starting and running power requirement of all electric appliances are different. An 18 Watts CFL takes around 25 Watts power to start and after few seconds it stabilizes to 18 Watts. Some appliances like Refrigerator, Washing Machine etc take almost double power to start as compared to the normal running power. Hence before selecting an inverter you must calculate the starting power requirement also.

Difference between VA and Watts

Often people confuse with the difference between Watts and VA ratings of inverter or other home appliances. Manufacturers use both these terms according to their requirements to confuse and mislead the consumers. Power drawn by the equipment (Power using equipment like Bulb, Fridge, Washing Machines, ACs, Stabilizers etc.) and Power generated by the equipment (Generators, Inverters, UPS etc) can be expressed in Watts or VA (Volt Ampere). In general Power generating or stabilizing equipment manufacturers use the term VA to specify their ratings and power consuming products use Watts to specify their ratings. Here comes the difference. Power in Watts is the real power drawn or supplied by an equipment, this is the real value. VA is the apparent power (more theoretical)  which is obtained by multiplying the Voltage and Current drawn/supplied by an equipment. We can equate the VA and Watts ratings:

Power in Watts = Power in VA- Losses


Power in Watts = Power in VA x Efficiency of the equipment

The ratio of Power in Watts to Power in VA is termed as Power factor. Unfortunately manufacturers often don’t specify the power factor or efficiency in their products.

Let’s see an example. You are purchasing an inverter with 650 VA power ratings. This 650 VA indicates, it can supply 650 VA power under ideal situations( means efficiency of the inverter is 100%). If we take 80% as a typical efficiency figure, the said inverter can supply 80% of 650 = 520 Watts only. Now you can understand why inverter manufacturers only publish the VA rating on their products. If an inverter or UPS is coming without mentioning power factor, you must take a safe value of 0.6 (60%) as power factor while connecting appliances.

Inverter or Home UPS?

Nowadays we can see a new segment in inverter market- Home UPS. Functionally both inverter and UPS do the same job- Converting Direct Current from batter to Alternating Current which is  used as a backup power generating device in case of mains power failure. UPS as the name suggest provide Uninterrupted Power Supply to equipment. The equipment will not feel the switching delay from mains to UPS supply. Switching over time of a typical UPS is 3 to 5 Milli Seconds only. A standard inverter takes around 500 Milli seconds which is unacceptable for the electronics devices like computers, Modems, Routers, printers etc.

Home UPS is a combination of Inverter and UPS. Here the switching delay of inverter has been brought down to UPS standard. Hence you need not to go for a separate UPS for PCs and associated devices. One thing you must remember- UPSs are further classified in to three- Offline, Online and Line interactive. Home UPS are normally Offline only, hence they cannot replace your online UPS requirements to drive sophisticated devices.

Digital Inverter

What is digital in inverters? First generation inverters were using power transistors as switching devices and transistorized circuitry for  monitoring/controlling applications. That is an old story. Nowadays inverter technology has changed a lot. A complete transition from old square wave technology to Pure Sine wave technology with the help of advanced Digital Signal Processing (DSP) techniques. Micro controllers are extensively utilized for précised monitoring and controlling applications. Switching transistors are replaced with high efficient MOSFETs.


Batter- the vital part of inverter. Performance and life of an inverter is greatly depends upon battery. We can see several classifications of inverter batteries. Normally high power Lead Acid batteries are used to power inverters. Lead acid batteries are classified in to different types as per application, design, technology etc.

Battery Capacity

Capacity of a battery is expressed in terms of Ampere Hour (Ah). It indicates the rate of current a battery can supply for a given duration. If the capacity of a battery is 100 Ah, that battery can supply 100 Ampere current for 1 Hour or 1 Ampere Current for 100 Hrs, 2 Amps Current for 50 Hrs .Capacity of inverter batteries are generally 100 Ah, 150 Ah or 180 Ah.

Why automotive batteries are not suitable for inverters?

Lead acid batteries used for automotive purpose are termed as “High Cycle” lead acid batteries. These batteries are designed to provide high current for a very short duration (To start the vehicles). Automotive lead acid batteries are not designed to be regularly discharged by more than 25% of their rated capacity. Here the requirement of inverter is totally different. Inverter require “Deep Cycle” type batteries to provide continuous power which can be discharged at least 50% of their rated capacity. Some good deep cycle batteries can be discharged over 80% of their capacity. Deep Cycle batteries have specially designed thick plates to withstand frequent charging and discharging.

Maintenance Free batteries

Lead acid batteries require regular maintenance. You have to check the electrolyte level and require to be topped up on regular intervals. Moreover these batteries release poisonous gases during charging and discharging. If you don’t keep the batteries in a properly ventilated place, it can invite serious health problems. You have to keep the terminals of normal lead acid batteries corrosion free by applying petroleum jelly or grease regularly.

Maintenance free batteries are sealed lead acid batteries which do not require topping up or additional ventilation.

Disadvantages of Maintenance free batteries:

  • Cost of Maintenance free batteries are very high as compared with normal lead acid batteries.
  • Life- Life of maintenance free batteries are comparatively low. For example if a normal lead acid battery run for 3 years, you can expect 2 years from a maintenance free battery.
  • Scrap value- You will not get much more from a maintenance free battery as scrap.

If you like a fit and forget inverter system or your situations don’t permit you to do periodic maintenance of batteries then go for a maintenance free battery. Let me quote one example- My friend uses Maintenance free batteries in his home because his old aged mother is living alone and she don’t have enough knowledge on battery maintenance. In that situation maintenance free battery is a right choice.

Tubular batteries

This is the most popular segment of inverter batteries-Tubular batteries have several advantages compared to flat plate batteries.  More complex design increases the manufacture cost but the high electrical efficiency and extra long life make tubular batteries suitable for both domestic and industrial applications. A good maintained tubular battery can run unto 8 years or more. Tubular batteries comparatively require less maintenance. Cost of tubular batteries can go up to double of a normal flat plate battery, however if you have a high efficiency inverter then go for a tubular battery, you will not regret. Almost all popular battery  brands in India like Exide, Prestolite, Amaron etc have specially designed tubular batteries for inverters.

Batteries from Inverter manufacturers

We can see that almost all inverter manufacturers supplies battery along with inverter. I strongly suggest-don’t go for such batteries. This is a simple business technique, often they just market batteries on their brand name. As battery costs more than inverter, it is always better to go for a  reputed and trusted battery brand. I have personal experience with Exide and Prestolite tubular batteries. Exide Invatubular batteries run flawlessly upto 5 years.

Local made batteries

We can see a common trend- People often go for branded inverter and local battery combination. Local batteries costs around 60% of the cost of same rated tubular batteries. However I don’t recommend local batteries because of the following reasons:

  • Poor life: A well maintained local battery can run maximum up to 3 years.
  • Poor efficiency: Electrical efficiency of local batteries are very poor, which requires more time to charge.
  • Safety hazards: Lead acid batteries are very much prone to explosion if not maintained well. We have witnessed several battery explosion incidents. Poor quality of safety vent plugs, casings, impure lead and acids increase the chances of accidents.
  • More maintenance: We can see that local batteries require more maintenance because of poor efficiency.
Flat Plate Batteriesexide inverter battery thumb Things to Keep in mind before buying an inverter Tubular Batteries
exide invatubular thumb Things to Keep in mind before buying an inverter
Maintenance Free Batteries (Sealed lead acid)
exide smf thumb Things to Keep in mind before buying an inverter
Battery Life Span Low (~ 3 Yrs) High(~ 5 Yrs) Medium (3 to 4 Yrs)
Maintenance High Medium Low
Cost Low High High
Safety Low Low High
Efficiency Low High Medium
Scrap Value High High Low

Warranty/Guarantee of Battery

First of all understand the difference between Warranty and Guarantee- Under the terms of Warranty you will get the maintenance and repair of items in free of cost but no replacement. A product under Guarantee will be get replaced in case of malfunctions. Normally we can see batteries are marketed under guarantee + warrantee combination , ie first few years Guarantee and after that warranty. Some brands offer even 48 months warranty. As battery is the costly and vital part of your inverter system, go for a brand which offer long term guarantee/warranty and after sales support.

Inverter output (Sine wave, Square wave, Stepped Sine wave)

inverter waveforms thumb Things to Keep in mind before buying an inverter

Our commercial power supply is 50 Hz pure sine wave (see the figure). However most of the inverters don’t output pure sine wave. Old inverters generate 50Hz square wave or 50Hz modified Sine wave (Quasi Sine wave , Trapezoidal wave or Stepped Sine Wave). Then the question comes. This wave shape really matters? Yes it does.

All commercial instruments are designed to run on pure sine wave. Characteristics of such devices are greatly depend upon the input wave shape. A change in wave shape will affect the performance of the appliances. Appliances like Motors, refrigerators, Ovens etc will generate full power on pure sine wave input only. Distortion in the sine wave creates humming noise in transformers, and audio devices. Some instruments like light dimmers, few battery chargers, toasters etc require pure sine wave to work. Prolonged operation of appliances in Square or stepped waves will considerably affect the life of such equipment due to the generation of heat.

You may be noticed that  audio amplifiers, Televisions, Fluorescent lamps etc make noise on inverter power. This indicates that inverter output is not pure sine wave. Sine wave inverters are costly as compared to square wave and stepped sine wave inverters, however it is always advisable to go for a pure sine wave inverter for the safety and effective performance of your appliances.

Square Wave Stepped  Sine Wave Pure Sine Wave
Safety of Appliances Less Moderate High
Life of Appliances Less Moderate High
Battery Life Less Moderate High
Noise Level High Moderate Normal
Heat generation High Low Normal
Suitability for sophisticated appliances No Not recommended for prolonged use Yes

Inverter efficiency and No load power consumption

Efficiency of an inverter is proportional to the amount of power drawn. It can varies from 90% to 50% from full load to light load. Here the notable factor is that inverter efficiency is high on maximum load. Generally an inverter is in its most efficient capacity when being used at around 1/3 to 3/4 of it’s full rating.

Power Consumption of inverters

Inverters take mains power supply to  charge the batteries. If the charging section of an inverter is not energy efficient, it will waste electricity even after the battery is fully charged. This will inflate your electricity bill. It is very difficult to check this aspect in shop before purchasing an inverter. However you can test the same at your home. Switch off all appliances except the  mains supply to inverter, disconnect the battery and measure the power consumption for a specific period.

Battery backup duration

Here we have an equation to find the battery life on load

Time(in Hrs) = Battery Voltage (In volts) * Battery Capacity (in Ah)*efficiency of inverter

                                                                           Load (in VA)

Let us have a sample calculation

Battery voltage = 12 Volts

Battery Capacity = 150 Ah

Load = Two fluorescent lamps (40 Watts each) and one ceiling fan (75 Watts )= 155 Watts

Inverter efficiency = 80%= 0.8

Backup Time = 12 * 150*0.8/155= 9.29 Hrs (Approx)

Other features

Solar Panel input: In typical Indian situations even eight hours of continuous commercial power supply availability can not be assured. Hence many people use the most reliable and alternate non conventional power source- Solar energy. Nowadays inverters facilitates the usage of Solar Panels also. Those inverters are embedded with solar charging circuits and regulators.

LCD Status Indicators: Modern inverters come with LCD status indicators to display various status like Battery charge level, Load, Input/Output voltages, Battery life etc.

Voltage stabilizer , High/Low voltage cutoff : Normal inverters don’t stabilize the mains supply, means the commercial supply is routed directly to the appliances without monitoring. Some inverters comes with in built voltage stabilizer , which protects your appliances from voltage fluctuations.

Earth Leakage Protection: Earth leakage protector is a safety device used to protect users from electric shock and appliances from damage. Modern inverters come with in built earth leakage protection circuits, which continuously monitor earth leakage and cut off the supply to safeguard the users.

After Sales Support

We can’t give a blanket suggestion in favor of a particular brand or model. All electronics equipment are prone to damage, hence after sales support is always paramount which varies from place to place. As inverters are static devices, go for a dealer or brand who offers on site warranty repair and maintenance.

Read this Home Solar Inverter Buying Guide


  • dinesh r 06/02/2014, 9:50 PM Reply

    Dear Sujith
    I have a inverter of 600va and and 80ah battery of 12v. Now recently I brought one more 80ah 12v battery connected in parallel.
    Now someone confusing me and they are telling me to connect the batteries in serial way. I have 18watts 4cfl., 3cieling fan, and tv. Please answer me what the difference it makes with series and parallel connection and which is better and which way I should go. Even now I am getting 3hours backup with 2cfl. Waiting for your answer to my confusion.

    • Sujith 06/06/2014, 4:04 PM Reply

      You must connect the same in parallel, not series. By connecting two 80ah batteries in parallel, your effective capacity doubles to 160 aH 12 volts. If your inverter rated input voltage is 12 Volts, you must go for this. If your inverter input voltage is 24 volt then you should connect the batteries in series here your net rating will be 80Ah 24 Volts. Normally inverters below 1 KVA work at 12 Volt input supply, hence connect 12 batteries in parallel to increase capacity.
      One thing more you need to know that, before connecting batteries in parallel, you must check the charging capacity of your inverter. If the inverter can’t give sufficient charging current, the batteries will not be fully charged.

  • Rajesh Bangari 06/04/2014, 12:10 AM Reply

    I need to use a symphony cooler 150 watts and a Dell Ultra Book ( Laptop)
    For 5 hour’s
    Suggest me an inverter suits this requirement.
    If possible provide me an online link to get the same.

    • Sujith 06/06/2014, 3:57 PM Reply

      A good 850 VA sine wave inverter with 150 Ah battery will be sufficient for your needs.

  • Padmaraj 06/05/2014, 11:28 PM Reply

    Dear admin I want to know whether I can use IT 750 with Exide 850VA inverter.Which is the best combination with Exide 850VA inverter, IT500 Super or IT750?
    Thank you in advance

  • Rana Rohit 06/06/2014, 11:51 PM Reply

    Dear sujith,
    Pls suggest what will be a best possible combination of invertor & battery which can fulfill my energy needs of below mention products with a handsome back up.
    5 cfl bulb
    3 ceiling fan
    1 symphony cooler 120 watt
    1 tv
    Kindly revert on priority basis & suggest best brand for invertor & battery.


    • Sujith 06/07/2014, 8:25 PM Reply

      Inverters above 1 KW demands 24 Volt battery, which doubles your budget. Hence go for an 850 Watt inverter with 150 to 180 Ah battery setup. SuKam, Microtek, Luminous etc are reputed and trusted brands. Go for the inverter batteries of Exide, Prestolite or Amaron

  • Raj 06/07/2014, 11:36 AM Reply

    I want your kind suggestion about buying a new battery and ups for
    my house, the load is about 650 watts,
    input voltage is very low, near about 160-170, if you tell me about some particular model in ups with stabilizer and a specific exide battery model it will be very helpfull,
    Thanks in advance…

    • Sujith 06/07/2014, 8:21 PM Reply

      If your input voltage is very low, a good 1 KVA stabilizer with 850 VA inverter 150 Ah battery combination will workout. Go for a brand which gives better after sales service at your area.

  • Joseph Kundan 06/07/2014, 3:11 PM Reply

    I must commend the writer – Sujithji – for this very well-written article covering all aspects to consider (without being too technical) when buying an inverter AND the battery (or batteries) which is a very crucial part of the whole backup system, in which most people compromise (usually influenced by a smooth-talking inverter salesman). I am particularly impressed that he has not ‘promoted’ any brand, except for ‘Exide’ (a reputed brand around for a long time, so no harm in that) I myself have had some experience using Su-Kam inverters and Exide batteries (since 2004) in Ladakh – an extreme weather condition place – (with electricity being supplied for 6 hours only in those days) and I have had very few issues with them. My first inverter was Su-Kam CHIC Digital Inverter (12V,760VA) purchased in Delhi and Exide Invaqueen 500 (12V 130Ah?) purchased in Leh (we did not have tubular batteries in those days). I have had no issues with either for 5 years, except once when I mistakenly re-connected the terminals other-way round (I used to charge my car-battery which had discharged over the winter). I dreaded taking it to the local electrical repair shop. But I didn’t have to – as the Su-Kam support was so good and detailed that all I needed to do was to change the internal DC fuse and voila! I was back in business. I, of course, kept a regular check on the battery electrolyte levels. We used the inverter not only for my desktop, laptop, TV and lights, but for the washing machine too! The inverter is still working. In 2009 I had to buy a higher-rated inverter since I had purchased a Laser Printer. This time I got a Su-Kam 1400VA (24V) UPS (I am not sure why it had both UPS and Inverter mode) I needed 2 batteries too (to be connected in series) and I was recommended to use 2 of the same make, rating and date of manufacture (Sujithji, I would like your opinion on this). This time some more options were available in Leh, so I got 2 new Exide Invared (Deep discharge) batteries. Again till date I had no problems with either and am still using it. Even in extreme cold (though I tried to keep the batteries ‘warm’ by housing it foam on the sides only). I get a power back up of 5-6 hours using laptop, LCD screen, laser printer (not continuously though), CRT TV, several CFL lights, and use the inverter to run the washing machine, fridge and water-pump too!

    My query is regarding solar-powered back-up systems for the home. (As you know, we have lots of sunshine in Ladakh, despite the cold.) I have not been able to do any research on this lately, so I would like your opinion/advice on the best/good solar-panels available (with approximate costs) able to adequately charge 24V (2x12V) 150Ah batteries. Is it possible to hook up the solar panels with the present 1400VA Inverter, so that the battery remains charged through mains at night when the days are cloudy? Are there integrated systems available (chargeable both from solar and electric sources)? Please suggest good ones.

    Sorry for writing such a long ‘comment’!! But once again kudos to you for the excellent comprehensive article. Would it be possible to update it, now that I am sure new technology in both inverters/UPS and batteries would have come up since you wrote in 2012. Thanks.

    • Sujith 06/07/2014, 8:17 PM Reply

      Hi Mr. Joseph Kundan
      Thanks a lot for your valuable comment. I will certainly update the article with the latest trend in battery and inverter marketplace. I have already written an article about Solar home inverters ( You can attach Solar panels with your present 1400 VA inverter through a conversion circuit. You should use at least 500 Watts panels for this system, however 1 KW is desirable. From a 1 KW plant you can get 4 to 6 Units of electricity per day. The cost of panel varies from Rs 30 to 50 Per watt (Varies from place to place and brand to brand). Before going for a solar power plant, just consult with MNRE nodal center for more details and availing govt subsidy. In your case the details of your regional MNRE center.

      Chief Executive Officer,
      Jammu & Kashmir Energy Development Agency (JAKEDA)
      12 BC Road, Rehari, Jammu.
      Tele:0191 – 2546495, 2552725(R), 2546495 (Fax)
      Dharrilla, Raj Bagh
      Tele Fax: 0194-2479791

  • Julian 06/08/2014, 11:56 AM Reply

    Hi Sujith,

    I have a question and it would be helpful if you could guide me.
    I have a triple bedroom house, I may have to use 2 tubelights, 1 ceiling fan, 1 37inch lcd/22inch crt Tv and 1 ac occasionally, I live in chennai and my area has a very high power fluctuation rate. Please let me know if i should get a generator or an inverter or both. I think that if i need an inverter may be a solar one would do because of the power fluctuation rate in my area.

    Also suggest me how to choose an inverter or a generator based on my requirement.

    • Sujith 06/08/2014, 4:05 PM Reply

      If you want to run ac, then drop the inverter plan and go for a suitable generator. If your budget permit, a combination of generator and inverter will be the best for you. Go for 850 VA inverter for light loads like, tube lights, ceiling fan, TV etc. Without air conditioner load, a 1 to 1.5 KW solar power plant can also be considered, it will be more economical in long run.

  • varun 06/09/2014, 3:44 AM Reply

    Great article written by you.
    I run a school at jammu and my usage is around 1.5 to 2 kW. We face high fluctuations and regular powercuts of around 2 hrs duration during working hrs. Please suggest me something to over come fluctuations and powercuts.

    • Sujith 06/09/2014, 3:48 PM Reply

      Go for a 1 to 1.5 KW solar power plant. No doubt, it will bring back your investment in long run. It will cost around 1 to 1.5 Lakhs after Govt subsidy.
      Normal inverters fails to handle power fluctuations, hence in your case if you go for a normal inverter, a good voltage stabilizer will also be required.

  • nikhil 06/09/2014, 9:40 PM Reply

    I have a 800 va inverter with a single 12 v 150 ah battery but now I want to make it a double battery system can I use the same inverter??

  • krishna 06/10/2014, 10:08 AM Reply

    please suggest me a good inverter for me for the following need.

    fans- 3
    fridge- 1

    • Sujith 06/11/2014, 7:48 PM Reply

      It is not desirable to use a fridge with low power inverter. If you want to use fridge you may require at least a 2 KVA inverter.

  • jijin 06/10/2014, 11:07 PM Reply

    Hi Sujith,
    That was an interesting n informative article..
    We have a three room set house.
    We need an inverter n battery tat wl help to power up 4 CFLs 3 fans during short power cuts…or we should be able work these equipments for at least 2-3 hrs..
    Requesting ur suggestions.

  • Dr. Abhijit Mohanty 06/11/2014, 2:58 AM Reply

    Hi Sujith,
    I have already purchased yesterday a 2 KVA / 24 V sine wave luminous inverter alongwith two nos.Exide invaplus FIPO-1500 battery type ie 150 Ah 12 V

    Questions: 1. Is the inverter compatible with the two batteries ?

    2. Do I connect in series ?

    3. On the batteries it is written, max inverter size upto 1.6 kva for 24 v system & max inverter size upto 800 va for 12 v system. What does this mean?

    3. Your suggestions plz if there are any other batteries that go better the inverter .

    • Sujith 06/11/2014, 7:45 PM Reply

      1. The inverter is compatible with the two batteries
      2. You have to connect two 12 Volt batteries in series to get 24 Volt input supply to inverter.
      2. For the 24 battery system ( Two batteries connected in series) the desirable inverter rating is 1.6 KVA. Normally inverters below 1 KVA use 12 Volt system and inverters upto 2 KVA use 24 Volt/ 48 Volt systems.

  • Bhavana 06/11/2014, 2:26 PM Reply

    Hi – I want to purchase a inverter for my home.

    Plan to use Maximum for about 4 hours:
    1 Fridge
    2 ceiling Fans
    2 CFL
    1 Laptop

    Have thought to put
    Exide IT500 Battery
    and Luminous Inverter 900va or 600 VA

    Please suggest if 600VA inverter will be ok or we should go for 900VA

    Also suggest if IT500 is good or should we go for higher or lower?

  • Ramesh 06/11/2014, 8:25 PM Reply

    Hi Sujith,
    I am planning to get a battery 100 Ah and i am going to use it for
    1 – Modem
    1 – Router
    1 – Laptop

    For 5- 6 hours.

    I am not able to keep the battery near window and i can able to put in a hall near to telivision it is advisable to use ?

    I am going to buy this battery (AAM-CR-I1000H29R) which aamran and heared that it is combination of acid + gel so that it can be place inside the hall.

    It is advisable to use this battery or can you suggest the battery which can be used in indoor ?

    Thanks for your time

    • Sujith 06/12/2014, 3:28 PM Reply

      You can place the battery in a well ventilated space not necessary to keep near to window. It is good to keep away from other electronic appliances like TV.

  • arun 06/12/2014, 11:23 AM Reply

    Hi, I want to buy an inverter for using following appliances during power cut & my requirement to get at least 5 hours backup for these equipment.

    1) CFL – 3
    2) Celeing fan – 2
    3) LCD – 32 ” – 1

    Also I add one cooler then what capacity inverter & battery I should buy.

    Thanks in advance.

    • Sujith 06/12/2014, 3:30 PM Reply

      For running cooler You may require at least 1.5 KVA inverter. For the indoor coolers like Symphony etc can go for the inverters below 1 KVA.

  • Sangram 06/12/2014, 1:02 PM Reply

    Pls suggest what will be a best possible combination of invertor & battery which can meet my energy needs of below mention products with a 4hr back up.
    5 cfl bulb
    3 ceiling fan
    3 tubelight



  • S R Sangwa 06/13/2014, 3:15 PM Reply

    Hello dear,
    kindly suggest an inverter – battery combination for my following need

    4 Tube lights
    4 CFL
    4 Fans
    1 42″ LED TV
    2 Laptops

    Duration 5-6 hrs minimum

  • vysakh 06/15/2014, 12:00 PM Reply

    I have sukam falcon 800v inverter and ameron 120 ah shield inverter a days my electricity bill increases.I checked with my battery servicer he said battery one shell is broken.but inverter charged properly after fully charged.he said it due to battery.I don’t think inverter rear fan works always until fully there any problem with that….please help urgently

  • Akshay 06/15/2014, 5:31 PM Reply


    Very informative article, quick question.

    Can I attach two 150A Batteries with my 3000VA Imported UPS in series? Currently there are 4 70Amp batteries attached to my 3000VA UPS in series, but as they have been used for 2 years now its time to replace them.

    What will be disadvantage of attaching two 150A Batteries instead of 4 70 Amp Batteries.


    • Sujith 06/16/2014, 4:28 PM Reply

      Rated input voltage of your inverter is 48 Volts (4 Twelve volts batteries in series 4 x 12= 48), hence you can’t attach two 150 VA batteries in series with the inverter. However you can use four 150 A batteries in series, subjected to the capacity of inverter. Charging current requirements of 150 Ah and 70 Ah batteries are different. The battery with the smaller capacity will be empty before the larger one, resulting in a lower voltage for the smaller battery hence it is not advisable to connect batteries with different ratings in series. You have to replace all the batteries at once.

  • Marq 06/16/2014, 10:12 AM Reply

    Hi Sujith,

    Need your guidance in ranking the brands of the basic inverters and batteries available in the market today.

    Ranking 1-10 where 1 is the highest and 10 is lowest

    Brands Inverter-Rating Battery-Rating
    Tata Green

  • Krishnakumar 06/16/2014, 11:32 AM Reply

    Dear Sujith Ji,

    kindly suggest an inverter – battery combination for my following need

    4 Tube lights
    2 CFL
    2 Fans
    1 42? LED TV
    1 Laptops

    • Sujith 06/16/2014, 4:22 PM Reply

      850 to 1 KVA inverter will be sufficient for you, however it depends upon the power failure duration

  • pradeep kumar 06/16/2014, 12:01 PM Reply

    I have bought su-kam 850 shiny invertor wich is pure shine wave invertor as shown on it. I want to know that is this invertor compitable for 32 inch led tv. Are there any disadvantages running tv on the invertor.

    • Sujith 06/16/2014, 4:20 PM Reply

      You can use 32 inch LED TV with a pure sinewave inverter. No issues with running tv on this inverter

  • FAZIL 06/16/2014, 8:23 PM Reply


  • logesh 06/17/2014, 3:01 PM Reply

    Hi Sujith,

    I request you to suggest a Inverter for my minimal use, I require 1 Fan + 2 CFL bulbs to run for 5 hours, pls suggest me a good one, Thanks!

    • Sujith 06/22/2014, 12:01 PM Reply

      300 VA is enough for your requirements but there is no much cost difference between 300 VA and 800 VA inverter. You can go for a 100 to 150 Ah battery as per your budget.

  • Piyush 06/18/2014, 2:43 PM Reply

    Dear sujith,
    what a great article.
    In simple language.
    I would really like your advice. I am going to buy a battery for my luminous 900va inverter. I live in rajasthan with sunshine 10-11 months. Can i connect solor panales with my invertor or would i have to buy a new one ? I need backup of atleast 4 hours. And what would be the cost of solor panles.
    My elctricity need.
    3 tubelights
    2 ciling fans
    1 crt tv
    1 laptop.
    Waiting for your suggestion.

    • Sujith 06/22/2014, 12:00 PM Reply

      Thanks for your comment, Luminous is already providing solar ready inverter models,. If you are planning to go for solar panels, and inverter is not purchased, it is advisable to go for a solar ready inverter model, by this you can save the money for solar power conditioner and switching equipment. 800 to 1 KVA is sufficient for your needs

  • samir 06/19/2014, 1:32 AM Reply

    My total appliances power is 5kw as i am having two AC & fridge. plus 2 leds. 4 fans & 4 tubelights. I want battery back up of minimum 10 hours. Which model should i choose. I wanna go for Luminous & Exide battery. How much range i will require. Luminous 3.5kva will be enough or not.. ?? & what about battery capacity how much it will require?

    • Sujith 06/22/2014, 11:57 AM Reply

      As per your requirement, inverter will not be a good option for you. Consider a suitably rated Diesel Genset. Optionally you can go for an inverter with less rating to supply the essential load during short duration power failure.

  • Deepak 06/19/2014, 3:51 PM Reply


    I will be soon renting a 1BHK flat and need to buy inverter. I have to put Inverter-battery component in Hall. My requirement is of 2 ceiling fans, 1 table fan, 1 laptop, 32″ LED TV, 1 Cooler for 8hours. Kindly suggest me some safe inverter-battery component to be placed in hall for my above requirement.


    • Sujith 06/22/2014, 11:55 AM Reply

      Go for an 800 VA inverter with 150 Ah battery combination. Even though Cooler with exhaust fan works in this configuration, it will not give much backup, hence go for an indoor cooler.

  • Sowmyan 06/21/2014, 9:06 PM Reply

    Thank you sujith, very informative article.

    I am planning to replace my battery. One question that is in mg mind, is: does tubular battery have better life than normal batteries? I plan to install it for my house.

    Thanks in advance for clarifying!

  • sanjay 06/22/2014, 11:35 AM Reply

    sir..i have microteck sine wave inverto SEBz 850VA, and i bought the Luminius Tubular battery ILTT18048 150AH. The proble is the invertor is unable to charge the battery.
    The battery person came twice and checked the battery and told that the battery is fine and told me to check the invertor.
    I took the invertor to local checking center and they told is invertor is fine and giving 8amps Current and when battery engineer put th clamp meter around the wires (when electricity is there) then is shows the current 3.5amps. so he again told that this current is not sufficient to charge the battery and tubular battery need 12amps current to charge…

    PLS Suggest where is the problem….

  • macho 06/23/2014, 10:03 PM Reply

    I have 850VOLT inverter and 150ampere exide battery so is it sufficient to use 140watt LED tv???and for how many hours???

  • Deepak 06/24/2014, 12:51 PM Reply

    Awesome article! Perfectly understandable. I am planning to buy an 850 VA inverter + 150 Ah battery. Is this sufficient to run

    * 4 tubelights
    * 4 fans
    * 1 laptop
    * 1 32″ LCD TV

    simultaneously for 6 hours? If not, how many of the above mentioned items can I run in parallel?

    Thanking you in advance,

  • Rohan 06/24/2014, 3:15 PM Reply

    Hi Sir,

    I recently bought a microtek ups eb700 va inverter along with okaya 135 ah tubular battery. Can you help me find out the backup time of the inverter on full load. Details below:

    Inverter – 12v
    Battery – 135 ah
    Inverter Efficiency – Not Known
    load – 2 cfl, 3 fans and 1 tv


  • Pallavi 06/26/2014, 1:57 PM Reply

    Hi Sir,

    I request you to let me know if an inverter in the range of 900 VA- 1kva will be able to run a mixer, microwave , fridge, TV , one fan , altogether for 2-3 hours? Is there any inverter battery combination that can run the above high load appliances altogether? Or may be we can run 1 or 2 together? Please suggest the best combination in the budget of 20 K

    Thanks a ton

  • Amit Jain 06/28/2014, 8:09 PM Reply

    Hi, I have a Microtek UPSEB 850 invertor. I do want to purchase a new battery. We have 3 celing fans, and 3 22w tubes and a tv to support. Can I use any battery I want to (Exide, etc.), or it has to be Microtek UPSEB 850 only. I couldnot find Microtek UPSEB 850 battery online.

  • Sreedhar 06/29/2014, 8:45 AM Reply

    Dear Admin,
    I’m planning to buy a inverter + battery. Regarding battery I’ve a confusion. Few dealers suggesting Tubular battery is better and few are saying Tubular batteries would take much power almost double no. of units for recharge compared to the normal one. Is it true? If we use tubular battery would our electricity bill more?? Please suggest me. Also, in could you please suggest the good brand among Microtek,Luminous and SUKAM inverters.. Each dealer is saying their own companies are good and others are failed :) So, kindly suggest me good inverter.

  • Madhur 06/30/2014, 3:04 PM Reply

    Great article Sujith. I am very hopeful that you can help me with my predicament.

    I want to install an invertor which can run 3 ceiling fans, 3 CFLs, 2 LCDs for at least 7-8 hours.

    Which invertor should I buy and what batteries? I understand Tubular would be a good choice however how many of them?
    Also, If i plan to run a 3 star 1 Ton split AC, then what should I go for?

    Please help me with this. Thanks!

  • Praveen 07/01/2014, 6:20 PM Reply

    Hello Sujith,

    Please suggest me one inverter & battery for below requirements:

    Tube lights: 5
    Ceiling fans: 4
    cfl bulbs: 4
    40 inches TV (will turn off as soon as power cuts)

    NEED BACK UP OF 6 hrs.

    Please reply

    Thanks in advance

  • G.Vinodh Kumar 07/03/2014, 7:46 AM Reply

    Dear Sujith,

    Good Morning,

    Can you provide your opinion on the below Inverter/Battery combination

    Sukam Shiny 850VA
    Sukam Big Conqueror SBT 1500 Battery.

    You have mentioned in your article not to go for batteries from Inverter manufacturer’s I am confused now please help me out.


  • Sameer 07/03/2014, 5:58 PM Reply

    Could you please let me know which 150AH battery should i choose between:

    Luminous Inverlast ILTT 18048 (150 ah) Tall tubular
    Amaron Current CRTT 150 ah – Tall Tubular

    (I dont have money to spend on Exide invatubular as it costs me 15000 plus)

  • Sameer 07/04/2014, 4:46 PM Reply

    very nice stuff from Sujith…. some info from my end… yesterday i bought a tubular Exide 100Ah battery called Inva Red 350+ for Rs. 8300 (after discount on returning my used battery) in Hyderabad … its supposed to run for 3 hrs (2 tubes + 2 fans) which is what i need … lets hope it runs well…. i referred this site and, …. some useful info there too….

  • Sunny 07/04/2014, 5:25 PM Reply

    Hello Sujit,

    I appreciate your article, good work

    Day before yesterday I bought one Microtek SEBz 1100 VA interverter with MtekPower EB 1800 Battery (150 AH). This model suits my requirements. However, I notice two issues:

    a) 21″ Panasonic CRT TV switched ON from Mains (it goes to Standby): I observed inverter moans, and tubelights are turned OFF and ON for a fraction of a second.

    Why is this happening? It’s not supposed to happen isn’t it?

    b) Significant drop in voltage at good load:
    3-4 tubes + 3-4 ceiling fans
    same 21″ TV
    Bajaj Water Cooler DC 2000 (guess up to 250 W rating)

    I couldn’t follow this problem because the inverter has enough deliverable power, i.e., 80% of 1100 = 880W.

    Are these problems due to faulty battery? or, Inverter itself? Wiring is clean.

    Please provide your inputs,

    Thank you

    ps: called Microtek Support Engineer to assess it

  • roy 07/06/2014, 12:33 AM Reply

    Hi sujith,

    I wish to buy 800VA V-Guard home UPS. I have already an 180Ah tubular battery.
    Is the 800VA inverter is sufficient for fully charging of 180 Ah battery.



  • Sunny 07/06/2014, 1:13 AM Reply

    Well, something strange happening when 21″ TV put to use.

    a) After inverter installation, Voltage was set to narrow range (180-260).

    Wall switch turned ON to power the TV – should be in Standby state.

    Result? Inverter goes haywire, triggers Overload LED, alarm beeps and power goes down in the home.

    b) One guy dealer support staff visited home to solve the TV issue. He then the set Voltage to Standard range (100-300).

    Wall switch turned ON to power the TV – should be in Standby state.

    Result? As written in (b) in OP, except:

    Sometimes I can watch the TV only when I turn on wall switch to bring set to Standby power with the help of AC power (before power goes), yet inverter load delivery (voltage) isn’t satisfactory (low light, less fan speed etc).

    Note: TV works along with Cooler on Inverter provided I should keep the TV in Standby mode just before power goes off.

    Anyway, I started feel like 17,000/- getting wasted. I’m somewhat confused with this weird experience.

    I hope Microtek Support Engineer has answers to this problem.

    ps: MtekPower battery is 8 Amp, with 10 Amp circuit breaker fuse.

  • Rajni Fulwadwa 07/06/2014, 4:47 PM Reply

    Hi sujith,

    Awesome analysis?

    Can you please tell me what va inverter is required for my below power needs

    2-3 cfl
    1 ceiling fan
    1 laptop
    1 router.

    Please suggest the best brand available in that va and also best price. Thanks.

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