12V /24V /48V Auto Recognition 20A 30A 40A 50A 60A MPPT Solar Charge Controller
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.
12V /24V /48V Auto Recognition High Efficiency MPPT Solar Controller
The best panel match for an MPPT controller:
To match a panel to an MPPT controller it is advisable to check the following:
The panel open circuit voltage (Voc) must be under the permitted voltage.
The Voc must be above the “start voltage” for the controller to “kick-in”
The maximum panel short circuit current (Isc) must be within the range specified
The maximum array wattage - some controllers allow this to be “over-sized”, e.g the Redarc Manager 30 is permitted to have up to 520W attached
The MPPT controller is best:
• For larger systems where the additional 20%* or more energy harvesting is worthwhile
• When the solar array voltage is substantially higher than the battery voltage e.g. using house panels, for charging 12V batteries
* An MPPT controller will yield higher returns compared with a PWM controller as the panel voltage increases. I.e. a 160W eArche panel using 36 conventional monocrystalline cells with a maximum power amps of 8.4A will provide around 8.6A at 12V; while the 180W panel having 4 more cells will provide the same amperage but 4 additional cells increases the panel voltage by 2V. A PWM controller will not harvest any additional energy, but an MPPT controller will harvest an additional 11.1% (4 / 36) from the 180W panel.
For the same principle, all panels using SunPower cells with more than 32 cells require an MPPT charge controller otherwise a PWM controller will harvest the same energy from 36, 40, 44 cell panels as it does from a 32 cell panel.