Maximum Power Point Tracking (MPPT) optimally matches the solar array to the battery—no wasted solar electricity. Morningstar MPPT Controllers feature TrakstarTM technology, an advanced control algorithmic function which harvests the maximum power possible from a solar array. Trakstar better maintains battery health by optimizing state of charge and protecting against overcharging and undercharging. All models incorporate advanced thermal design requiring no cooling fans, which ensures long-term reliability with no moving parts to fail. This is a unique feature among higher- powered controllers.