how to choose a right ups(inverter) for home

in these days most common question is  How to choose a best UPS(inverter) ?
answer is first you need to know types of ups(inverters), There are many types inverters available in pakistan, but we will  talk about    1 pure sine wave  2 modified sine wave
Pure Sine wave : Pure Sine Wave UPS(inverters) provide electrical power similar to the utility power you receive from the outlets in your home or office, which is highly reliable and does not produce electrical noise interference associated with modified sine wave inverters, you can run your sensative load without problums like mobile chargers , fans without any sounds, computers  etc

Modified Sine Wave : modified sine wave inverters are cheap(inexpensive) then pure sine wave inverters and do not offer the same perfect electrical output like home utility. electrical noise of these inverters are  cause to produce sounds like hum in fans and can demage your fan regulater and mobile chargers ,but you can run most appliances of your home,

Power Requirement: it is very simple if u hate with calculations, easy way is

2 fan + 2 tube lights = 500va
3 fan + 3 tube lights = 800va
4 fan + 4 tube lights = 1100va
So if you want to run 3 fans, 3 tube lights ,  you would need 800VA inverter.
Battery  Selection
if u want to run 3 fans with 3 lights for 3 hours you must select 150ah batery
if u want to run 4 fans with 4 lights for 3 hours you must select 200ah batery
wrong battery can demage your inverter
Read more about electronics on Electronicabc.com