Ups for pc

can any tel me the good ups available in cheap rates for my pc which can give 15 to 30 minutes backup time only for khi

UPS can range frm 3000 to 5000, as far as I knw and give a backup time of 15-25 minutes

I askd this frm a hardware store

Please use Chinese UPS with external batteries. Best companies are Homage and Mercury.

if you want to have a long time backup attach batteries with UPS.....

[quote=", post:, topic:"]

Please use Chinese UPS with external batteries. Best companies are Homage and Mercury.
[/quote]

I need a UPS with dry batteries with output of about 3500-4000 watts and backup time of about 7-8 hours on full load. Must have full (or at least limited) warranty of 2-3 years.

If you have any knowledge from where I can get such and for how much, please post here