1. Introduction
Thank you for choosing the VOTRONIC MPP 350 Duo Digital Solar Charge Controller. This device is engineered for efficient and reliable charging of 12V battery systems in motorhomes, caravans, boats, and other off-grid applications using solar panels. Utilizing Maximum Power Point (MPP) technology, it ensures optimal energy yield from your solar modules. This manual provides essential information for safe installation, operation, and maintenance of your solar charge controller.
2. Safety Instructions
- Read this manual completely before installation and operation.
- Installation must be performed by qualified personnel in accordance with all applicable electrical codes and regulations.
- Ensure all power sources are disconnected before making any electrical connections.
- Do not expose the device to moisture, extreme temperatures, or direct sunlight.
- Verify correct polarity for all connections to prevent damage to the unit and batteries.
- Use appropriate fuses as specified in the technical data.
- Keep children away from the device and electrical connections.
- Do not attempt to open or repair the unit. Refer all servicing to authorized personnel.
3. Product Overview
The VOTRONIC MPP 350 Duo Digital Solar Charge Controller is a compact and robust unit designed for optimal solar energy conversion. Below is an image illustrating the main components and connection points of the device.
Figure 1: Overview of the VOTRONIC MPP 350 Duo Digital Solar Charge Controller. Key features include the solar panel input terminals, battery 12V output terminals (I+II and BORD), a 30A fuse, and LED indicators for charge status and battery levels. Connections for a solar display, temperature sensor (TS), AES, and EBL are also visible.
The controller features clearly labeled terminals for solar panel input, main battery (I+II), and auxiliary/starter battery (BORD). A 30A fuse is integrated for protection. On the right side, a series of LEDs indicate the charging status and battery levels. A dip switch allows selection of different battery types. Additional ports are available for connecting an optional solar display, temperature sensor, and other system components.
4. Setup and Installation
Follow these steps for proper installation of the MPP 350 Duo Digital:
- Mounting: Choose a dry, well-ventilated location, away from direct heat sources and flammable materials. Ensure sufficient space around the unit for air circulation.
- Battery Connection: Connect the main battery (Battery 12V I+II) to the corresponding terminals on the controller. Ensure correct polarity (+ to + and - to -). Then, connect the auxiliary/starter battery (BORD) if applicable.
- Solar Panel Connection: Connect your solar panels (up to 350Wp / 21A) to the 'Solar-Panels' input terminals. Observe correct polarity. The maximum solar voltage should not exceed 50V.
- Temperature Sensor (TS): Connect the optional temperature sensor to the designated 'TS' terminal. This allows for temperature-compensated charging, optimizing battery life.
- Solar Display (Optional): If using an external solar display, connect it to the 'Solar-Display' port.
- Battery Type Selection: Use the dip switches on the side of the unit to select the correct battery type (Pb, Gel, Acid/AGM1, AGM2, LiFePo) for your main battery. Refer to the label on the unit for voltage settings.
- Final Check: Double-check all connections for tightness and correct polarity before applying power.
5. Operating Instructions
Once installed and powered, the MPP 350 Duo Digital will automatically begin charging. The unit employs an IU1oU2 charging characteristic for efficient and gentle battery charging.
LED Indicators:
- AES: Indicates Automatic Energy Saving mode.
- Batt. Full: Illuminates when the battery is fully charged.
- > 80%: Indicates the battery charge level is above 80%.
- MPP: Illuminates when the Maximum Power Point tracking is active and optimizing solar yield.
- Batt. Low: Indicates a low battery voltage, requiring attention.
Battery Type Settings:
The dip switches allow you to set the charging voltage profile according to your battery type:
- Pb (Lead-Acid): Standard lead-acid batteries.
- Gel: Gel batteries.
- Acid/AGM1: Acid batteries or AGM1 type batteries (typically 14.4V).
- AGM2: AGM2 type batteries (typically 14.8V).
- LiFePo: Lithium Iron Phosphate batteries (typically 14.2V).
Ensure the correct battery type is selected to prevent damage and ensure optimal battery lifespan.
6. Maintenance
The VOTRONIC MPP 350 Duo Digital is designed for minimal maintenance. However, regular checks can ensure optimal performance and longevity:
- Connections: Periodically check all electrical connections for tightness and corrosion. Loose connections can lead to overheating and poor performance.
- Cleaning: Keep the unit clean and free of dust and debris. Use a dry, soft cloth for cleaning. Do not use liquid cleaners.
- Ventilation: Ensure that the ventilation openings are not obstructed to allow for proper cooling, especially for the temperature-controlled fan.
- Fuse: If the unit is not functioning, check the integrated 30A fuse. Replace only with a fuse of the same rating.
7. Troubleshooting
If you experience issues with your MPP 350 Duo Digital, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No charging activity | No solar input; Blown fuse; Incorrect wiring; Battery voltage too low. | Check solar panel connections and sunlight; Check and replace fuse; Verify all wiring connections and polarity; Ensure battery voltage is above 1V. |
| Low charging current | Insufficient sunlight; Dirty solar panels; Incorrect battery type setting; High cable resistance. | Ensure panels are in direct sunlight; Clean solar panels; Verify correct battery type setting; Check cable gauge and connections. |
| Overheating | Poor ventilation; Overload. | Ensure adequate airflow around the unit; Reduce load or check system capacity. |
| Battery not fully charged | Insufficient solar power; Incorrect battery type setting; Battery degradation. | Increase solar panel capacity or improve sun exposure; Verify battery type setting; Consider battery testing or replacement. |
If the problem persists after attempting these solutions, please contact VOTRONIC customer support or an authorized service center.
8. Specifications
| Parameter | Value |
|---|---|
| Model | MPP 350 Duo Digital |
| Nominal Battery Voltage | 12 V |
| Max. Solar Input (Amperes) | 21 A |
| Max. Solar Input (Watts) | 320 W |
| Max. Solar Voltage | 50 V |
| Min. Battery Voltage for Operation | 1 V |
| Number of Charge Outputs | 2 (Main: 24A, Auxiliary: 1A) |
| Charging Characteristic | IU1oU2 |
| Self-Consumption | 0.0045 A |
| Battery Types Supported | GEL, AGM/Lead-Acid, LiFePo4 |
| Operating Temperature | -40°C to +45°C |
| Dimensions (L x W x H) | 131 x 40 x 77 mm |
| Weight | 0.61 kg |
| Certifications | CE (CEM/Control according to KFV-Directive) |
9. Warranty and Support
VOTRONIC products are manufactured to high quality standards. For specific warranty terms and conditions, please refer to the warranty card included with your product or visit the official VOTRONIC website. Keep your proof of purchase for warranty claims.
For technical support, troubleshooting assistance beyond this manual, or service inquiries, please contact your authorized VOTRONIC dealer or the VOTRONIC customer service department. Contact information can typically be found on the manufacturer's website.
