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The power backup solutions are popularly known as Power inverter or inverter in India. Choosing the right inverter and battery are the critical decision factors in building the right power backup solution. In this article, we discuss in choosing the right type of battery and right capacity or size.

Try our inverter selector to choose right inverter by answering simple questions without reading any buying guide.

The three main components of the power backup solution are

1. Power grid to charge battery
2. Inverter battery to store DC current
3. Inverter

Inverter buying guide

Power grid is default and electricity connection at your home. The power from the power grid recharge the battery. At the event of power cut the battery DC current needs to be converted to AC current with the help of Inverter. But in general the total power backup solution is called as inverter in India. We discuss the inverter and battery buying guides in two different sections as elaborately as possible.

First calculate your power requirement

The first thing is to calculate how much backup you want, or how many appliances you want to support. The general power consumption about common appliances is listed in below table.

Appliance
Power requirement
Fan
80
Tube light
40
CFL
20
LED bulb
7
Television
120

Say you want to support 4 fans, 3 tube lights, 3 CFL bulbs, 2 LED bulbs and one Television. The total power requirement is (4*80 + 3*40 + 3*20 + 2*7 + 120) = 634 watts. So you need inverter which can support 634 watts.

Inverter capacity calculator

Inverter capacity is directly proportional to total load that you want to support. The accurate formula is total load to be supported, divided by the power factor. There is efficiency loss in the conversion of energy that indicated by power factor. In other words we are balancing the energy efficiency by dividing with the power factor.

The inverter capacity is measured in Volt Ampere, often abbreviated as VA. In all the product description the VA rating is mentioned. Please see below picture on how to identify the VA rating.

For earlier example, we have mentioned for the power requirement of 634 watts, the required VA rating of the inverter is 634 / 0.8 = 792 VA. The nearest inverter with matching need is 900 VA. So better consider 900 VA inverter to support your power requirement.

Inverter VA vs Battery WA

The inverter capacity is measured in VA and battery capacity is measured in WA. We will discuss more about battery capacity in battery buying guide. People wonder why there are two capacities? What is the purpose of each capacity?

The simple analogy is this. Consider ‘water well’, you use bucket tied to a rope to pull the water from the well. The water in the well can be compared to the battery capacity, than the size of bucket is inverter capacity. You can see as the battery capacity is total electricity stored and inverter capacity is how much you can serve at single time.

So there should be proper match between the battery capacity and inverter capacity. Even you buy large capacity battery, and low capacity inverter (example: 600 VA) then you cannot support refrigerator or few fans, because their total load exceeds the 600 VA.

Sine wave inverter vs Square wave inverter

As we discussed earlier inverter converts DC current to AC current. But depending on how the AC current looks like, the inverters are classified as Sine wave inverter or Square wave inverter. The detailed differences are mentioned below in a table:

Feature
Square wave inverter
Sine wave inverter
Supported appliances
Motors
Computers, laptops, refrigerators, ovens
Noise level
High, creates humming noise in inverter as well as in appliances
Normal
Safety of appliances
Less
High
Price
Economical
High

It is always good to have Sine wave inverter even though they are costly for the sake of safety and longevity of the appliances. There are modified sine wave inverters too which are cheaper than sine wave and costlier than square with moderate performance. In some sense they are placed in between sinewave and squarewave and very few models available in the market so you can safely ignore them. You can read more about Sine wave inverter vs Square wave inverter in our other post.

Inverter vs UPS

The main difference is the time delay. UPS is used on general only to backup your system. If you connect desktop computer on inverter, any power loss, shutdowns the computer as it takes one microsecond to fall over to the backup power solution. Inverter is not suitable for computer backup due to the delay in switching. The computer crash not only leads to the lost of data, unsaved programs, but also may damage hard disk and motherboard. Know more about difference between ups and inverter in our other post.

Feature
UPS
Inverter
Use case
Provide backup to Desktop, computer backup
Provide backup to TV, fans, lights, household appliances
Time delay to switch at the event of power cut
Negligible
Microsecond
Backup time
10 to 20 minutes
3 to 6 hours, depending on battery and inverter
Maintenance
No maintenance
Need to fill water toppings at regular intervals of time.
Price
2,000 Rs - 6,000 Rs
10,000 Rs - 40,000 Rs

Before you buy Inverter check the wiring of home

The homes should have facility or provision for backup. It is easy to provide backup for total home with the help of inverter from the main source. But to provide backup to total home you need large size battery and inverter. Most of the cases, people wants to provide backup to only few selected fans, lights and appliances. In that case, wiring should be in such a way to allow to run few selected appliances on the inverter. So first consult your technician about the wiring and get it done before you purchase inverter and battery.

Bigger appliances require high power requirement to start the appliance, for example AC and refrigerator. In general to support refrigerator 1k VA inverter, and to support 1 ton AC, 2.5k VA inverter is needed. The battery requirement is also high. So you should exclude these big appliances from the inverter wiring.

Best Inverter brands

The famous inverter brands are Luminous, Microtek, Exide, APC and Exide. Most of the brands also sells the Battery along with the inverter. It is good to buy the combo as you don’t need to worry about the compatibility. We are listed few handpicked inverters here for your reference.

Best handpicked sine wave inverters

• Luminous Zelio 1100 VA Sine Wave Home UPS Inverter Pure Sine Wave Inverter
• Su-Kam Falcon+ 750 Pure Sine Wave Inverter
• Su-Kam Falcon+ 900VA/12V Pure Sine Wave Inverter
• Exide 850va Home ups + Exide 150AH Battery
• Exide 850va Home ups + Exide 150AH Battery
• Su-Kam Falcon++ 1100/12V Pure Sine Wave Inverter
• Su-Kam Falcon + 1100 Pure Sine Wave Inverter
• Luminous Zelio 1100va + Exide 150AH Battery
• Luminous Zelio 1100va + Exide 150AH Battery
• Luminous Zelio 1100va + Exide 150AH Tubular Battery

Best handpicked square wave inverters

• Su-Kam SHARK 900 VA Square Wave Inverter
• Su-kam Shark 1600Va Home UPS inverter
• Luminous Rapid Charge 1650VA /12V Single battery Square Wave Inverter
• Su-Kam Shark 700 Va Square Wave Inverter
• Microtek UPS-700EB Square Wave Inverter

Where to buy the inverter online

All the top brands inverters available online in the market. Unlike batteries, the Inverters are not hazmat products. The products are available in Amazon, Flipkart and other top e-commerce stores. Please see manufacturers site and buy the latest model. Be clear about returns and shipping policy before placing the order.

Final checklist for before finalising Inverter

• If you are first time buyer, try to purchase the Inverter, battery combo.
• It is good to buy Inverter trolley, so that you can place inverter, battery inside a trolley. It is easy to move if you place the Inverter, battery in a trolley. Before buying trolley make sure you have enough place in home to put the trolley
• Finally, make sure your home have proper earthing, to avoid accidental electrocution.
• Look for warranty, longer warranty means better products. As we have mentioned the price of battery increase if the warranty increase.

Inverter Battery buying guide

How to calculate battery capacity?

The battery names looks like Luminous 120Ah Tubular Battery, Power Bank Series - 50AH - 220 AH, Macroz Series - 25AH, 50AH. You might wonder what are the terms AH or Ah. AH or Ah is an acronym for Ampere Hour, meaning the amount of current the battery can supply for the specific duration. 100Ah battery capacity can be expressed in the following ways.

• 100 Amperes of current for 1 hour
• 50 Amperes of current for 2 hours
• 25 Amperes of current for 4 hours
• 1 Ampere of current for 100 hours

The formula to calculate the battery size is given below. It is simple total load multiplied by backup hours and the final result is divided by voltage.

Total load in watts

The formula to calculate the battery size is given below. It is simple total load multiplied by backup hours and the final result is divided by voltage.

It is the number of watts you need or devices in your home consume. Say you want to backup 6 lamps of 40 watts each and 3 fans of 75 watts. Then your effective power requirement of the total load is 6*40 + 3*75 = 465 Watts.

Backup in hours

A number of backup hours you need. Now you can clearly see as the number of backup hours increases the required battery size also increases.

Voltage

The voltage of battery cell. Usually, it is referred as Nominal voltage. Almost all of the top brands of batteries have 12V or 12 voltages. We guess 24V and 48V batteries are not available in India.

Below table beautifully present the examples of calculating battery size, you can call it as inverter battery calculator.

Power requirement
Backup in hours
Suggested battery size
600 Watts
2 hours
(600 * 2) / 12 = 100Ah
900 Watts
2 hours
(900 * 2) / 12 = 150Ah
1000 Watts
3 hours
(1000 * 3) / 12 = 250Ah

Battery types

In general, inverter batteries are divided into two categories namely Lead Acid battery and Lithium battery. Again Lead Acid batteries are three types. Flat plate battery, Tubular battery, Sealed Maintenance Free(SMF)battery. Every battery varies depending on the internal technology used to store the current. The features which differ are safety, efficiency, battery life, maintenance, and price. A detailed analysis of every battery type is mentioned below.

Flat plate battery

Flat plate batteries are the most commonly used type for home inverters. They require frequent maintenance, including the addition of distilled water every 3 to 6 months. These batteries have a shorter lifespan and are less safe, emitting poisonous gases. As such, they should be placed in well-ventilated areas. Due to these disadvantages, flat plate batteries are being replaced by tubular batteries.

Tubular battery

Tubular batteries also require the addition of distilled water but less frequently than flat plate batteries. They have a longer lifespan, better efficiency, and are safer compared to flat plate batteries. However, they are more expensive.

Feature
Flat plate battery
Tubular battery
Maintenance free batteries
Battery Life
Low (~ 3 Yrs)
High (~ 5 Yrs)
Medium (3 to 4 Yrs)
Maintenance
High
Medium
Low
Water toppings
High
Medium
Low
Safety
Low
Low
High
Releases harmful gases
Yes
Yes
No
Ventilation requirement
Yes
Yes
No
Weight
Low
High
Depend on the model.
Price
Rs. 9,000 to Rs. 15,000
Rs. 9,000 to Rs. 25,000
More than Rs. 11,000
Top Brands
Amaron, Exide, Luminous, Su-Kam
Amaron, Exide, Luminous, Su-Kam
Luminous

Lithium Battery

Lithium batteries are the latest trending technology in the world of batteries and do not require maintenance. They do not contain sulfuric acid and do not emit hazardous gases. However, they are very expensive, around one lakh Indian rupees, compared to conventional tubular batteries which cost about 15,000 to 20,000 Indian rupees.

Lead acid battery vs lithium-ion battery

Aspect
Lead-Acid Batteries
Lithium Batteries
Material
Lead plates, sulfuric acid electrolyte
Lithium compound cathode, graphite anode, electrolyte (varies)
Maintenance
Requires maintenance (e.g., topping up water)
Maintenance-free
Cost
Lower initial cost, higher lifetime cost due to replacements and maintenance
Higher initial cost, lower lifetime cost due to durability
Cycle Life
Limited, typically 200-500 cycles
Longer, typically 500-5000+ cycles
Charging Time
Slower
Faster
Self-Discharge Rate
Higher
Lower
Weight
Heavier
Lighter
Size
Larger
Smaller
Environmental Impact
Contains lead and acid, requires proper disposal/recycling
Generally considered more environmentally friendly due to fewer toxic components and longer lifespan

Avoid local battery manufacturers

It is not recommended to buy local brand batteries because they usually do not follow safety and efficiency standards and tend to have a short lifespan. Local batteries often emit harmful gases and require excessive maintenance work. Moreover, they generally do not come with a warranty or guarantee.

Look for inverter compatibility

Always check for battery inverter compatibility. The ideal battery capacity is total power multiplied by backup hours and the final result is divided by voltage. The inverter VA is directly associated with the total power required. If you are buying the inverter for the first time, it is good to go with inverter and battery combos which ensure compatibility.

Select long battery warranty

Longer warranty is always better even if it costs more. Battery guarantee means the battery is freely replaced in case of damage within the specified duration, while the warranty refers to the duration for which free repair is done. Knowing these terms helps when it comes to replacements and repairs.

Top brands and after sales support

Top and well-known brands in India for inverter batteries are Amaron, Exide, Luminous, Okaya, and Su-Kam. Reliable after-sales support is crucial for unexpected scenarios like battery repair or replacement. Many top brands even provide a distilled water top-up facility.

Brand
Product links
Customer care number
Amaron
Amaron batteries
1800 425 4848
Exide
Exide batteries
1800 103 5454
Luminous
Luminous batteries
1800 103 3039, 1860 500 3939

Inverter battery prices

Inverter battery price depends on the type of battery, brand, capacity, battery warranty, and the dealer. Replacing the old battery can offer up to 10% to 20% off the new battery price. Prices also vary