How long can a UPS supply power to a laptop. Meanwhile UPS stands for Uninterrupted  Power Supply. The capacity of a UPS depends on the battery it is fitted with. A UPS consists basically of a battery and an inverter. 

To get a sense of how long a UPS can power your laptop check its battery capacity.  The smallest UPS comes fitted with a 7AH battery. Theoretically, it should power a laptop rated 60w for 1.4 hours when fully charged.

But in reality, this is not the case. A laptop rated 60w may not last more than 30 minutes.Why is this so?, the UPS converts DC to AC and in the process, a lot of energy is lost.The battery may have deteriorated considerably upon storage before the UPS was sold.

So if you really want a UPS that can power your laptop for 2 – 3 hours and above, get a UPS fitted with an 100AH battery and above