Thank you all for your comments and sorry for my late reply, as its night here when its your day time.
The specification of the UPS i can't ever get for you because its locally made and sold heere in the market without any details of it. No mention of what type batterries we should attched to it. Everyone uses wet batteries because deep cycle ones are really expensive here and old stuff that has been in the shelves for years. Even if i do buy it, it won't run for more than a year or at most two. So in that cost i can get 3 wet batterries of the same amperage and run them for 3-4 years easily.
The UPS is 600watts and it can run 4 fans and 4 tubelights. Each fan is 80w and each tubelight is 40w. That is what the UPS was made for, it did give me 1 and half hours of backup for 3 fans and a light when the battery was new, but its just year old and the backup is so low. I know that it won't be able to charge again this early because as i told you all that electricity goes for 2 hours 3 times a day. So i can se why the less backup, but the amazing thing is that the UPS says the battery is fully charged and still the same backup. At most when fully charged it gives me 1 hour backup for 2 fans and then i have to close one fan and it run for half an hour more, and with it two small energy saver bulbs of 11w each.
The UPS is on 12v, 600w output. Its also eating up my electricity bill because its always on charging with minimum or no efficiency at all. The only problem i can see is that the battery is fine but the UPS's own efficiency is not giving the backup. The same battery as you all rightly mentioned give 4 hours of backup if attached to a normal 650va, 390w APC or PCM UPS which i have. But those are just 400w and the problem is that the built in charger takes 4-6 hours just to charge a 7AH battery how will it charge the 145ah battery and give results.
The UPS business is hot here because of the electricity problem and the prices are sky high and quality very very low. The things that are being imported here are c grade chinese ups. That you all will call junk. But due to monopoly and the cost of working here people are not ready to import the good stuff because they won't be able to sell it.
I myself imported good quality UPS for computers about 2 years ago and the problems i faced only i know, the junk was being sold like cakes and even if i presented my good quality UPS to them they were not ready to buy from me at my cost price even becuase of the cut they got from the other suppliers.
As for the "free" battery part, Yes free but new.
Yeah atlast we are going to get a new President, hope things work out now but really can't hope too much.
I think i have cleared many points i could, now please can anyone help. I thought of changing the UPS too but the next one will be same too as only those are available here and i don't have more money for a new one again. All i can do is work with the things i have, also trying to build a wind turbine hope it gets ready and works well just to charge the battery and atleast save me from the charges of the UPS's charger eating up my bills.
Thanks in advance to all of you.