Following on from a previous post regarding misleading UPS specifications, we’ve put together the UPS Runtime Calculator which you can use to check the runtime for a variety of battery configurations on many different UPS types.
UPS runtime is mostly determined by the load and the battery. Higher capacity UPS need not necessarily give longer runtime for the same load. For example a 1500W UPS like the KR1500J contains an attached battery containing 8x9Ah batteries. For a load of 1000W this will give 20 minutes of runtime. The E203R however, is a 2400W UPS, but contains 6x7Ah batteries giving a runtime of 10 minutes.
Generally speaking for these professional UPS, manufacturers and dealers tend to be more accurate with the runtime figures. It’s at the budget end of the market where runtime information becomes a little bit vague.
I’ve seen adverts for 600VA UPS giving 45 minutes runtime, yet the unit contains only 1x7Ah battery. At a load of 300W, the runtime would be only 4 minutes. To get anywhere need 45 minutes, the attached load would have to be under about 50W.
The UPS Runtime Calculator can be used on for any UPS containing 7Ah, 9Ah or 12Ah or equivalent batteries. You need to know the number in the UPS, enter the load and hit Calculate. The estimated runtime will be displayed.
For the Power Inspired range of products, you can simply select the product of interest, enter the load and the runtime will be calculated.