The N6705B DC Power Analyzer can be used to capture the dynamic current profile of a battery powered device. http://www.keysight.com/find/N6781
Design changes can be quickly evaluated to determine the impact to the battery run time. The DC Power Analyzer allows you to data log over a period of time and then analyze the waveform post acquisition, all from the front panel. In this example we used the N6781A module which feature seemless current ranging so both the low level idle current and the peak transmission current can be captured in a single pass.
In this video the current profile of a wireless temperature sensor is captured. A new lower power design wireless temperature sensor is compared with the original design.