MPPT Charge Controllers
A solar charge controller, also known as a solar regulator, is basically a solar battery charger connected between the solar panels and battery. There are two main types of solar charge controllers, PWM and MPPT, with the latter being the primary focus of this article due to the increased charging efficiency, improved performance and other advantages.
PWM solar charge controllers
As shown in the diagram, PWM controllers force the panel to operate at the battery voltage (12V) which is less efficient.
MPPT solar charge controllers
As shown in the diagram, MPPT controllers enable the panel to operate at it’s optimum power (Vmp) voltage which is more efficient. As a general guide, MPPT charge controllers should be used on all higher power systems using two or more solar panels in series, or whenever the panel operating voltage (Vmp) is 8V or higher than the battery voltage.