Introduction to a Inverter
In lame mans terms, Difference between a inverter and UPS is the switch over time (The time needed for the Inverter to wake up and give out electricity). Generally for lighting a house an Inverter is good enough. I would anyway suggest more reading on UPS (Online and Offline), Invertors and Generators.
Generally on any inverter you cannot run Water Pump, Washing Machine, Gyeser etc.

Why I chose APC ?
I brought the inverter around the May 2005 timeframe. My main reasoning
for the pick was the packaging looked neat (with battries and power unit) and it was a reputed company.

Facts and figures ...
Power Rating: 800VA, 500W. Good enough for simple lighting and a TV. Calculate for yourself ..
A tubelight takes 40W, Fan about 70W, TV about 80 W, Mixie about 200W (But use it only for a span of 2-3 minutes).
Backup Time : On full load, it runs for Approx 2 hrs
Number of Battries : 2 Lead Acid battries, 12V, 70Ah
Wiring : House wiring should be such that the heavy electricals (Fridge, Gyser, AC etc) are on a seperate circuit line and the lighting is on a seperate line. The inverter will be connected only to the Lighting circuit.
 Overloading : In case of overload, Inverter continously beeps for about 1 min. After that it simply trips.
Cost : Total unit including 2 battries and power unit ... About 14K.
Pure Sine Wave : Well, this is a marketing gimic and debetable. For the cost you pay you will never find a pure sine wave invertor.
Warrenty : 2 years, replacement
Power Consumption: About 25% increase on monthly bill. But depends on the amount of power cuts you have. Generally for every 1 hr the inverter runs on battery, it needs to be charged for 4 hrs. When charging ... it takes about 1 unit (@750kwh) for every 3hrs.

Experience
For the first 14 months the inverter worked real good. After that the trouble started. Replaced the power unit under warrenty. The customer service are cheaters, they gave a power unit which was faulty and over charging the battery (The battries get heated up and the distilled water needs to be topped up every 2 week once). I realised after the warrenty elapsed.

Customer Service
As already indicated, they are number one cheaters. Under warrenty period there is some response. After the warrenty period, i would suggest to throw the inverter out. Its impossible to get any response from customer service and we always need to contact the service head.
During the warrenty period there is a free service mebest ntioned, but this is simply topping up the distilled water, again this is not done at the frequency prescribed by the battery manifacturers..
Iam got into the AMC trap (950/- for power unit alone) hoping i will get a better service, but very soon realised this is not helping. Under the AMC they replaced the inverter charging unit again, but this guy was still overcharging ... screwing up the battries and hogging quite a lot of power. The service person indicated that the battries are faulty so has to be replaced. I checked with Exide, i found that a pair of battries will cost me approx 8K, also when i told them the symptoms i observed in the inverter
they indicated its not battery problem, but inverter. (I agree with this, I did quite some research on lead-acid battries)

Note :The local brands are cheaper but customer service is always bad. Inverters are generally
 maintinance intensive and you will need a excellent customer support for inverters !! I see APC no better than local brands. I would prefer picking up a local brand which is generally 30-40% cheaper than APC.


Final Solution : Well, self help is the best help. APC is incapable of fixing the problem, so i resorted for a patch solution. I purchased a "change over" switch (a 3 pole one costs about Rs.150/-) and connected one end to Inverter, second to Main supply and other to House. So i use the inverter as a tourch ... when power goes off, i switch the changer over switch ... voila i have power back at home. Now i have a flexiblity to decide how long do i want to charge the battries. SO most of the time the inverter actually is kept powered off.
I felt this was a decent solution and good enought for household purpose.

Purchase Price (INR):	14000
Voltage of the inverter:	220V, 500W, 800VA
Which equipment do you usually use it on?	Home Lighting
Do you use it quite often?	Yes