SR-ML2420 MPPT Solar Charge Controller User Manual

1. Introduction

The Aexit SR-ML2420 MPPT Solar Charge Controller is an advanced device designed to optimize the energy harvesting from solar panels and efficiently charge various battery types. It features sophisticated Maximum Power Point Tracking (MPPT) technology to ensure maximum power extraction from your photovoltaic system, even under challenging conditions like partial shading.

This controller is suitable for 12V and 24V battery systems and offers high conversion efficiency, making it an ideal choice for off-grid solar power applications.

2. Key Features

• Advanced MPPT Technology: Utilizes dual-peak or multi-peak tracking to accurately find the maximum power point, even with shaded panels or multiple peaks on the I-V curve.
• High Efficiency: Features a proprietary algorithm for maximum power tracking, resulting in 15% to 20% higher charging efficiency compared to traditional PWM controllers. Circuit energy conversion efficiency up to 98%.
• Fast Tracking: A combination of multiple tracking algorithms ensures accurate tracking of the optimum working point in a very short time.
• Versatile Battery Compatibility: Supports various battery types including gel, sealed, open (flooded), and lithium batteries.
• LCD Display: Integrated LCD provides real-time system information and allows for easy parameter configuration.

3. Product Overview

4. Setup and Installation

Before installation, ensure all components are present and undamaged. Disconnect all power sources, including solar panels and batteries, to prevent electric shock or damage to the controller.

4.1 Mounting Location

• Mount the controller vertically on a non-flammable surface.
• Ensure adequate ventilation around the controller to dissipate heat.
• Avoid direct sunlight, high temperatures, and humid environments.
• Maintain a minimum clearance of 150mm (6 inches) above and below the controller for proper airflow.

4.2 Wiring Instructions

Follow the wiring sequence carefully to avoid damage. Always connect the battery first, then the solar panel, and finally the load.

1. Connect the Battery: Connect the positive and negative terminals of the battery to the corresponding battery terminals on the controller. Ensure correct polarity. The controller will power on and display system information.
2. Connect the Solar Panel: Connect the positive and negative terminals of the solar panel array to the corresponding PV terminals on the controller. Ensure correct polarity. The controller will begin charging the battery if solar power is available.
3. Connect the Load (Optional): Connect the positive and negative terminals of your DC load to the corresponding load terminals on the controller. Ensure correct polarity.
4. Connect the Temperature Sensor: Plug the included temperature sensor into the designated port on the controller. Place the sensor near the battery to enable accurate temperature compensation for charging.

Important: Always connect the battery first and disconnect it last. Incorrect wiring sequence can damage the controller.

5. Operating Instructions

5.1 LCD Display and Buttons

The controller features an LCD display for real-time monitoring and three buttons for navigation and setting adjustments.

• Up Button: Used to navigate upwards through menus or increase parameter values.
• Down Button: Used to navigate downwards through menus or decrease parameter values.
• Enter/Set Button: Used to confirm selections or enter setting modes.

5.2 Monitoring Parameters

The LCD cycles through various parameters automatically. You can also press the Up/Down buttons to manually cycle through them.

• Battery Voltage
• Solar Panel Voltage (Vmp, Voc)
• Charging Current
• Load Current
• Battery Temperature
• Total Charged Energy (kWh)
• Total Discharged Energy (kWh)

5.3 Battery Type Setting

The controller supports different battery types. It is crucial to set the correct battery type for optimal charging and battery longevity.

1. Press and hold the Enter/Set button to enter the parameter setting mode.
2. Use the Up/Down buttons to navigate to the battery type setting.
3. Press Enter/Set to select the option, then use Up/Down to choose your battery type (e.g., Gel, Sealed, Open, Lithium).
4. Press Enter/Set again to confirm and save the setting.

6. Maintenance

Regular maintenance ensures the longevity and optimal performance of your solar charge controller.

• Check Connections: Periodically inspect all wiring connections for tightness and corrosion. Loose connections can cause overheating and poor performance.
• Clean the Controller: Keep the controller clean and free of dust and debris. Use a dry cloth to wipe the surface. Do not use liquid cleaners.
• Ventilation: Ensure that the ventilation openings are not blocked to allow for proper heat dissipation.
• Battery Inspection: Regularly check your batteries for signs of damage, swelling, or leaks. Ensure battery terminals are clean.
• System Performance: Monitor the system's performance via the LCD display. Note any unusual readings or behavior.

7. Troubleshooting

8. Specifications

Note: Specifications are subject to change without prior notice.