The term Maximum Power Point Tracking, MPP-Tracking or MPPT denotes a procedure in electrical engineering, more closely in photovoltaics, in which the electrical load of a solar cell, a solar module or from mulitple in series connected solar modules is adjusted in such a way, that the most possible power can be extracted from the cells. With solar cells this optimal operating point isn't constant, but rather depends on irradiance, the temperature at the solar module and the type of solar cell. In addition a function as a charge controller for batteries consists.