MPPT Solar Charge Controllers

The MPPT controller could be considered to be a “smart DC-DC converter”, i.e. it drops the panel voltage (hence “house panels” could be used) down to the voltage required to charge the battery.  The current is increased in the same ratio as the voltage is dropped (ignoring heating losses in the electronics), just like a conventional step-down DC-DC converter.  

The “smart” element in the DC-DC converter is the monitoring of the maximum power point of the panel which will vary during the day with the sun strength and angle, panel temperature, shading and panel(s) health.  The “smarts” then adjusts the input voltage of the DC-DC converter – in “engineering speak” it provides a matched load to the panel. This equates to reduced charge times and optimum energy harvesting.