This paper proposes a simple current-sensorless MPPT with dc-dc boost converter for Photovoltaic battery chargers. The proposed tracker eliminates the use of the current sensor by using only the voltage sensor: The current sensor is substituted with a new quantity that employs both of the input voltage and the duty ratio of the converter. An empirical observation is used to develop a theoretical prove for this quantity. Then, the proposed tracker is designed in MATLAB Simulink and implemented using a fixed-point DSP. Moreover, a breadboard circuit has been built-up for testing the use of the proposed tracker with a dc-dc boost converter operating in continuous conduction mode. Experimental results show that the proposed tracker attains good dynamic and steady-state performances comparable to that obtained with the conventional MPPTs. A substantial part of the manufacturing cost and complexity burdens of MPPTs involves the use of current sensors. Considering this investigation saves cost, decreases complexity, and increases the efficiency and the power density of the MPPTs.