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Charging and Activation Logics
MPPT Technology
Based on MPPT (Maximum Power Point Tracking) technology, the charge controller can
extract maximum power from the solar panel. With an automatic tracking algorithm, the MPPT
technology can track the voltage of the maximum power point that changes with weather
conditions, ensuring the harvest of the maximum power throughout the day.
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Current Boost
Generally, the charge controller will “boost”
the current in the solar system. The power generated
in the solar panel is the same as the power delivered to the battery pack. Power is the product
of voltage (V) x amperage (A).
Therefore, assuming 100% efficiency:
Power In = Power Out
Volts In * Amps In = Volts out * Amps out
The efficiency of the charge controller is about 92% to 95%. As the maximum power point
voltage of the solar system is greater than the battery pack voltage, the potential difference is
proportional to the current boost. The voltage of the solar panel needs to be stepped down to a
rate at which the battery can be charged in a stable manner. Compared with traditional charge
controllers, the charge controller does not waste the stepped down voltage. It is entirely possible
to have the solar module input 8 amps of current into the charge controller, and have the charge
controller output 10 amps of current to the battery pack. The following shows a graphic point
about the output of MPPT technology.
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Current vs.Voltage (12V System)
Output Power (12V System)
Typical Battery
Voltage Range
Traditional
Controller
Operating
Range
Maximum
Power Point
Maximum
Power Point
Current
Power
Voltage
Voltage
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Limiting Effectiveness
High temperature is the natural enemy of solar panels. With the increase of ambient
temperature, the operating voltage (Vmp) of the solar panel decreases, which limits the power
generation of the solar panel. The charge controller encounters an inevitably decrease in
charging performance even with the MPPT technology. In this case, it is better to use solar
panels with higher nominal voltage, so that the battery can still get current boost even if the
voltage drops proportionally.
Charging and Activation Logics
MPPT Technology
Four Charging Stages
Lithium Battery Activation