MPPT Charge Controller (Maximum Power Point Tracking)
A charge controller that continuously searches for the highest power point on the panel's current-voltage curve and steps the power it finds down to the battery voltage with a converter. Because it does not tie the panel voltage to the battery voltage, it gives a marked gain with high-voltage panels and at low temperature.
The power of a photovoltaic panel depends on the voltage it is operated at and reaches its highest value at a particular point on the curve. An MPPT controller finds this point by changing the input voltage in small steps and measuring the power, and it keeps tracking it as the irradiance changes. A switching converter then turns the excess voltage into current.
The gain depends on conditions. If the panel's maximum power point voltage is markedly above the battery voltage — in cold weather, for instance, or with panels connected in series — the difference is noticeable. If the panel voltage is already close to the battery voltage, as on a hot summer day, the difference between MPPT and PWM narrows. That is why it is not correct to present MPPT as a device that gives a fixed percentage gain in every condition.
In an RV, MPPT is advantageous in installations where the number of panels increases or long cable runs are needed; high voltage means low current and cable losses fall. Setting the controller correctly for the battery chemistry is more decisive than the gain.
The context in which this term is used: RV automatic levelling guide