30min-1hr battery backup wanted

[assasin]

hi ppl!

at present i'm using an APC Back-UPS RS 1100va (double battery) but its giving me only 18-20mins backup and it costs 7.3k
i want backup for bout 30min-1hr (30min minimum).so wat pwr solution do u ppl suggest,keeping in mind that i want something which will provide me with same reliabilty as APC.i've a max budget of say 7.5k but the lower the better.

Thnx

[infra_red_dude]

why don't you go in for fast switching time inverter system? that'll give you sufficient backup (limited only by the battery that you connect to it).

[Choto Cheeta]

Note the Post from 509

All Calcuttans in Digit

[assasin]

^^^ in that thread u mentioned that APC 500va has 12A battery but my APC 500va has 7A batt.i've tried connecting 2*7Amp batt to this ups but it wont even switchon (shows alternating red & amber light)

[Choto Cheeta]

make sure u connect in parallel setup... not in serial...

Refer to this picture (note vule is not for ur use, just look at the setup)

[assasin]

^^^ hey man i tried it out in parallel this time and the ups did pwr on.but the prob is when is switched off the mains to test the battery backup it just pwred down my pc and started to give overload warning.