(1) Maximum Power Point tracking technology. The controller uses Buck conversion circuit and MCU technology to track the maximum power point to implement the maximum output power of solar panels in different illumination intensity and temperature. The MPPT algorithm increases efficiency of your PV system and decreases
the quantity of solar panels.
The starting charging voltage of battery is different; the controller will use different charging strategies to finalize the charging process. When starting charging voltage is lower than 12.6v (for 12V battery), the battery will go through three stages as Bulk, Absorption and Float charging when starting charging voltage of battery is higher than 12.6V (for 12V battery), battery will got hrough two stages as Bulk and Float charging.
The controller charges the battery at the maximum output current. At this stage, it is in the maximum power point tracking state.
The controller begins to limit the charging current to make the battery voltage at a settled absor ption voltage (this voltage has temperature compensation) for two hours. It increases the charg ing saturation level of battery and prevents battery from leaking gas, and can increase the lifeti me of battery.
(2.3)Floating Charge The battery is at saturation state, and the controller charges the battery at a trickle current to make the battery voltage fixed at the settled float charging voltage (this voltage has temperature compensation)
Maximum Power Point Tracking (MPPT) is an advanced charging technology that enables the solar panel to output more power by adjusting the electric module’s operating status. Due to the nonlinearity of solar arrays, there exists a maximum energy output point (maximum power point) on their curves. Unable to continuously lock onto this point to charge the battery, conventional controllers (employing switching and PWM charging technologies) can’t get the most of power from the solar panel. But a solar charge controller featuring MPPT technology can continuously track arrays’ maximum power point so as to get the maximum amount of power to charge battery Take a 12V system as an example.As the solar panel’s peak voltage (Vpp) is approximately 17V while the battery’s voltage is around 12V,when charging with a conventional charge controller, the solar panel’s voltage will stay at around 12V failing to deliver the maximum power. However, the MPPT controller can overcome the problem by adjusting the solar panel’s input voltage and current in real-time, realizing a maximum input power. Compared with conventional PWM controllers. the MPPT controller can make the most of the solar panel’s max. power and therefore provide larger charging current. Generally speaking, the latter can raise the energy utilization ratio by 15% to 20% in contrast with the former.