Inverter buying guide along with battery calculate and buy

How to use perfect inverter by Usage?

Calculate the units or power wattage for an hour and multiply the number of hours you required for backup.

I want daily 3 hours of backup


Laptops 5 average use of laptop power consumption per hour 60W (check on the battery). but desktop use 200 Watts per hour.


fan*2 =60W

Tubelight=40w   550W per hour *3  1.650 KWH. (1 and a half unit)

150 AH battery

ah to watts

amps to watts 24 volt battery with 24 watts circuit then amp = 1.

100 AH battery provides 5Amps for 20 hours. 100*12=1200watts

how many watts a 150ah battery provides?

A 12 volt 150 AH battery can deliver 12volts at 150 amps for 1 hour.
A 150AH battery, if its 12 volts, can deliver 150 times 12 watt-hours, or 1800 watt-hours. that’s 1800 watts for one hour

Watthour = Ampere hour * Voltage

  • Refrigerator
  • TV
  • AC


lead Acid batteries Flat plate battery

automotive batteries Filled with lead acid regular maintenance needed. reusable. but releases poisonous gasses. Low cost.
3-6 months we have to fill the distilled water.
Battery cost: 10-15K

Deep Cycle DRY batteries

No maintenance, no gases once the lifespan completed we need to buy the new one. expensive. sealed batteries or Deep Cycle, SMF Sealed Maintenance Free or VRLA (Value Regulated Lead Acid).

Luminous and Okaya

Top Brands India by serial: Amaron, exide, luminous, Sukam.

 tubular battery

10K to 25K for 150 Ah battery
the tubular battery can run unto 8 years but more efficient and expensive.
Lithium batteries
Battery size = total load in watts *Backup hours/ voltage.

Note: For fist time users always buy Inverter with Battery Combo.

UPS vs Inverter

Inverter Capacity (VA), Battery Capacity (Ah)

UPSs are further classified into three- Offline, Online, and Line interactive.

uninterrupted power supply No power loss within microseconds. but with the inverter, it can happen.

UPS Price 2k to 6k, inverter 10K-40K.

AC Current vs DC Power: DC (from powerline) flows one way but Ac (from inverter) current flows appliance to source and source to the appliance.

How to choose the best Inverter by capacity?

what we need 1700 watts for an hour. then 1700*0.8= 1360 VA nearest Inverter we need to pick.inverter capacity measured by serving capacity at each single time.

500 VA inverter cannot server to refrigerator and AC etc.

Square wave inverters are used in motors and sign wave inverters are used in the refrigerator, ac home appliances.
I just quoted from two dealers
1st Amaron battery and Ups  
880 VA UPS and 150AH*1 Battery 15900/ INR.
Tata batteries 150 AH *2, 12K*2=2400
1700 VA Luminous UPS  1000 INR but He offered at 24000 INR.
Here is a good source for battery guide at Zelcet.