Battery run-time on a laptop is difficult to determine. Actual battery running time depends upon the power demands made by the equipment. The use of the screen, the hard drive and other accessories results in an additional drain upon the battery, effectively reducing its running time. The total run-time of the battery is also dependent upon the design of the equipment. Generally, a new Hi-Capacity Acer aspire one battery will run 30% to 50% longer than the old battery did when it was new.