Uninterruptible Power Supply (UPS) is increasingly becoming popular as a means of providing conditioned and uninterrupted power supply to sensitive and non-sensitive loads at critical and non-critical times.Sensitive modern equipment with very low tolerance for power fluctuation and failures are on the increase due to advancement in science and technology, theseequipment however require power backed up if they are to perform optimally. This study focuses on modification of the UPS in order to extend its running time.A used and dumped UPS working at a back-up time of between 0 to 10mins was modified to accommodate two, 75AH Lead acid batteries, using 1400VA Zinox UPS. An extended backup time of between 2hrs to 8hrs on the same UPS using Lead Acid/Deep Cycle batteries was achieved which at the same time operating within a very low budget.