MPPT charge controllers convert all the solar electricity voltage possible into useable electricity. They operate at maximum power voltage (Pmp) which is higher than battery voltage. MPPT’s maximum conversion efficiency is ideal in intermittent sun and cloudy conditions, and in cold weather where they boost module output more than in warm weather. MPPT controllers have less module restrictions than PWM controllers so they can also be used with 60 cell modules that are often unsuitable for PWM controllers. Because of additional circuitry, MPPT is more complex and expensive. Morningstar TrackStar™ MPPT technology is the industry’s reference standard.