Many current smartphones need to be recharged every day despite only average usage. This problem is intensified when phones need to track their location on a continuous basis. We provide a yet unavailable platform for accurately measuring the energy consumption of different hardware / software solutions comparing up to three variants in a mobile setting. We show that the accuracy of our system is similar to a fixed, commercial system but is especially useful to evaluate and optimize technology and algorithms that require the phone to be used on the go.