1. Introduction
The SRNE MPL2420 is an advanced Maximum Power Point Tracking (MPPT) solar charge controller designed for 12V/24V solar street light systems. It efficiently manages power from solar panels to charge batteries and power loads, ensuring optimal performance and longevity of your solar setup. This manual provides detailed instructions for installation, operation, and maintenance.
Figure 1: Front view of the SRNE MPL2420 MPPT Solar Charge Controller, showing model number, battery voltage, max solar power, solar Vmp, solar Voc, max charging current, and max load current.
2. Key Features
- MovingTrack MPPT Technology: Utilizes advanced Maximum Power Point Tracking technology for higher tracking efficiency and faster speed, optimizing solar energy harvest.
- Battery Compatibility: Compatible with both lead-acid and lithium batteries. Operating parameters can be customized via remote control.
- UltraGreen Power Control: Features UltraGreen power control technology, ensuring extremely low power consumption and sleep current for enhanced efficiency.
- Lead-Acid Battery Charging: Provides multi-stage constant voltage charging with temperature compensation for lead-acid batteries, prolonging battery life.
- Flexible Load Modes: Supports various load operation modes including Normally On, Light control + time control, and charging-only mode, adaptable to different system requirements.
- Temperature Protection: Includes battery charge and discharge high and low temperature protection, with settable operating temperature ranges.
- Infrared Communication: Enables infrared wireless communication for setting/reading parameters and checking status.
- Comprehensive Protections: Equipped with multiple safety features such as battery/PV reverse polarity protection, load short-circuit/over-current protection.
- IoT Remote Monitoring: Extensible to IoT remote communication monitoring functionality for advanced system management.
- Durable Design: Features a full aluminum housing and IP67 waterproof rating, making it suitable for various harsh outdoor environments.
3. Product Selection Table
The SRNE MPL series offers various models with different features. Refer to the table below for a detailed comparison.
Figure 2: Overview of SRNE MPL series controllers, including MPL1210-R, MPL1215/2410-R, MPL2415-R, and MPL2420-R, highlighting their main features.
| Product Models | Description |
|---|---|
| MPL-R | MPPT Solar Charge Controller (-R: infrared remote control) |
| MPL-UL | With IoT remote control (built-in Lorawan module) |
| MPL-GP | With IoT remote control (built-in GPRS module) |
| MPL-C | With IoT remote control (RS485 interface, external communication module is required) |
| MPL-CT | With IoT remote control (TTL interface, external communication module is required) |
4. Indicator and Remote Control Status
The MPL series controllers feature three red indicators to display operational status. Understand their meanings for proper monitoring.
Figure 3: Table detailing the status of PV, BAT, and LOAD indicators, along with their descriptions and corresponding remote control system status.
| Indicator | Status | Description | Remote Control System Status |
|---|---|---|---|
| PV indicator | Steady on | Solar panel voltage is higher than light control voltage | Idle |
| Off | Solar panel voltage is lower than light control voltage | Idle | |
| Double flash | Fully charged | Fully charged | |
| BAT indicator | Slow flash | In charging | Charging |
| Quick flash | BMS protection or BAT overvoltage or PV overvoltage or over temperature (ambient temperature) or poor/current limited charging | E-BMS, Battery overvoltage, PV panel overvoltage, Over temperature, Overcurrent | |
| Steady on | Battery works properly | Idle | |
| Off | Battery is not connected or lithium battery protection board over discharge protection | Over discharge | |
| LOAD indicator | Quick flash | Battery over-discharge | Discharging |
| Steady on | Load is turned on | Idle | |
| Off | Load is short circuited | Short circuit |
5. Electrical Wiring Diagrams
Proper wiring is crucial for the safe and efficient operation of your solar charge controller. Follow these diagrams carefully.
A. Wiring Diagram of the controller with built-in IoT module
Wiring sequence: Firstly connect the load, then the battery, and finally the solar panel.
Figure 4: Wiring diagram showing connections for solar panel, battery, and load to an SRNE controller with a built-in IoT module. Note: The controller with antenna is an IoT type.
B. Wiring Diagram of the controller with external IoT module
Wiring sequence: Firstly connect the external IoT module, then the load, then the battery, and finally the solar panel.
Figure 5: Wiring diagram illustrating connections for an external IoT module, solar panel, battery, and load to an SRNE controller. The communication line interfaces are defined as Red VCC, Black GND, Yellow A/T, and White B/R.
6. Installation Method
Ensure the controller is installed in a suitable location with adequate ventilation. Refer to the dimensions below for mounting.
Figure 6: Dimensional drawings for various SRNE MPL series models, including overall dimensions, mounting dimensions, and mounting hole diameter. For MPL2420, overall dimensions are 155*114*34mm, mounting dimensions are 116*102mm, and mounting hole diameter is φ3.5mm.
- MPL2420 Dimensions: Overall dimensions: 155*114*34mm. Mounting dimensions: 116*102mm. Mounting hole diameter: φ3.5mm.
- Ensure the mounting surface is flat and secure.
- Allow sufficient space around the controller for heat dissipation.
7. Load Mode Settings
The controller supports different load operation modes to suit various application scenarios.
- Light control + time control mode:
When the working time in the first period is set to "1 - 14", no sunlight is present, the solar panel voltage is lower than the light control voltage, and after a time delay, the controller will switch on the load. The load will be switched off after working for a preset period of time and the maximum working time is 15 hours.
- Normally on mode:
When the working time in the first period is set to "15", the load is a normally open module. The energized load keeps outputting, and this mode is suitable for loads which need 24-hour power supply.
- Charging mode:
When the working time in the first period is set to "0", the load does not work, only the charging function, charging during the day, and automatically entering the sleep mode at night, reducing system loss.
8. Technical Parameters
Detailed specifications for the MPL2420 controller.
Figure 7: Comprehensive table of technical parameters for MPL1210, MPL1215, MPL2410, MPL2415, MPL2420, MPL2430, and MPL2440 models.
| Item | Value (MPL2420) |
|---|---|
| System voltage | 12V/24V |
| Static power consumption | ≤6mA/12V, ≤10mA/24V |
| Sleep power consumption | ≤2mA |
| Load Maximum current | 20A |
| Load working period | Normally On mode/9-Period + Pre-dawn lighting |
| Period adjustment range | 1min / 10min |
| Maximum solar input power | 260W/12V, 520W/24V |
| Maximum charge current | 20A |
| Maximum solar input voltage | ≤100V |
| MPPT Tracking efficiency | ≥99% |
| Charging conversion eff. | 85%-98% |
| Over voltage | PB-16.0V; LI-charging voltage+2V; ×2/24V system |
| Limited charge voltage | PB-15.5V; LI-charging voltage+1V; ×2/24V system |
| Equalizing charge voltage | PB-14.6V; LI-without balanced charge; ×2/24V system |
| Equalizing charge interval | PB:30 days; Lino: - |
| Boost charge voltage (lead-acid) | 8.5V ~ 17.00V settable; ×2/24V system |
| Charge voltage (lithium) | 8.5V ~ 17.00V settable; ×2/24V system |
| Floating charge voltage (lead-acid) | 8.5V ~ 17.00V settable; ×2/24V system |
| Charge return voltage (lithium) | 8.5V ~ 17.00V settable; ×2/24V system |
| Over discharge voltage | 8.5V ~ 17.00V settable; ×2/24V system |
| Over discharge return voltage | 3V ~ 11V; ×2/24V system |
| Light control voltage | 3V ~ 11V; ×2/24V system |
| Temperature compensation coefficient | PB: -3.0mV/°C/2V; Lithium battery: no compensation |
| Light control delay | 5s ~ 60s/2min ~ 60min |
| High temperature charge | 40°C ~ +90°C |
| Low temperature charge | 0°C ~ -35°C |
| Operating temperature | -35°C ~ +65°C |
| IP rating | IP67 |
| Protections | Battery reverse polarity protection, solar panel reverse polarity protection, solar panel over-voltage protection, lithium battery overcharge and over-discharge protection, lithium battery BMS overcharge detection protection, load short-circuit, load open circuit and short circuit protection |
| Weight | 770g |
9. Typical Curves
These graphs illustrate the typical charging and efficiency characteristics of the controller.
12V Lead-acid Battery Charging Curve
Figure 8: Graph showing the voltage and current profile during charging of a 12V lead-acid battery by the SRNE controller over time.
24V Lead-acid Battery Charging Curve
Figure 9: Graph illustrating the voltage and current profile during charging of a 24V lead-acid battery by the SRNE controller over time.
Charge Conversion Efficiency VS Input Power - 12V battery
Figure 10: Graph depicting the charge conversion efficiency percentage against input power (W) for a 12V battery system, showing performance at different Vmp levels (18V, 30V, 45V).
Charge Conversion Efficiency VS Input Power - 24V battery
Figure 11: Graph illustrating the charge conversion efficiency percentage against input power (W) for a 24V battery system, specifically for Vmp 45V.
10. Safety Precautions
Always observe the following safety guidelines to prevent injury and damage to the controller or other components.
- Read all instructions carefully before installation and operation.
- Ensure all wiring is correctly polarized and securely connected to prevent short circuits or damage.
- Do not attempt to disassemble or repair the controller yourself. Contact qualified personnel for service.
- Install the controller in a well-ventilated area, away from flammable materials and direct sunlight.
- Wear appropriate personal protective equipment (PPE) such as gloves and eye protection during installation.
- Disconnect all power sources (solar panel and battery) before performing any wiring or maintenance.
- Ensure the system voltage matches the controller's specifications (12V/24V).
- Keep children away from the solar power system components.
11. Troubleshooting
This section provides general guidance for common issues. For specific error codes or complex problems, refer to the indicator status table or contact support.
- No Power/Indicators Off:
- Check battery connections and voltage.
- Verify solar panel connections and ensure sufficient sunlight.
- Ensure the controller is correctly wired to the battery first.
- Battery Not Charging:
- Check solar panel voltage and current.
- Ensure solar panel is clean and not shaded.
- Verify PV indicator status (should be slow flash or steady on during charging).
- Check for reverse polarity on PV or battery connections.
- Load Not Working:
- Check load connections and ensure the load is not short-circuited or overloaded.
- Verify BAT indicator status (should not be off due to over-discharge protection).
- Check load mode settings (e.g., if in "charging mode", load will not operate).
- Ensure battery voltage is above the over-discharge return voltage.
- Over-temperature Protection:
- Ensure the controller is installed in a well-ventilated area.
- Reduce ambient temperature if possible.
- Check for obstructions around the controller's heat sink.
12. Warranty and Support
Specific warranty information for the SRNE MPL2420 controller is not provided in this manual. Please refer to the product packaging, your purchase receipt, or contact your retailer for warranty details.
For technical support or service inquiries, please contact the manufacturer or your authorized dealer. Ensure you have your product model number (MPL2420) and purchase details ready when seeking assistance.