Votronic MPPT 25A Duo (Dual) 350 Marine Version Solar Charge Controller
Votronic MPPT 25A Duo (Dual) 350 Marine Version Solar Charge Controller
Humidity-Proof Dual-Battery MPPT Controller for 350Wp Solar Arrays
Highlights:Solar Panel Terminals: Connection points for solar panels up to 350Wp and 21A,Dual Battery Terminals: Outputs for simultaneous charging of main board battery and vehicle starter battery,30A Protection Fuse: Integrated 30 Amp blade fuse for circuit protection,Status Indicators: LED indicators for AES, battery full, charge status, and MPP mode,Peripheral Port: Connections for temperature sensors, AES refrigerator output, and EBL displays,Solar Display Port: RJ45 connection for external Votronic solar computer or display units.
Key features: Simultaneous charging for house and starter batteries, Compatible with Votronic LCD Solar Computer S display, Support for solar panels up to 350Wp, AES output for refrigerator control, Temperature sensor input for battery thermal compensation.
Technical specifications comparison for Votronic MPP Duo Digital models 165, 250, 350, and 430, detailing solar capacities, charging programs for LiFePO4, and physical dimensions. 
DESCRIPTION
Votronic MPPT 25A Duo 350 Marine Solar Charge Controller: Precision Dual-Battery Charging for Harsh Environments
Advanced MPPT Technology for Maximum Solar Yield in Marine and Mobile Applications
The Votronic MPPT 25A Duo 350 Marine Version is a high-performance solar charge controller engineered for demanding off-grid energy systems in motorhomes, caravans, and marine vessels. Utilising Maximum Power Point Tracking (MPPT) technology, this controller continuously optimises the power output from your solar array, delivering up to 30% more charging current compared to conventional PWM controllers. This efficiency gain is particularly noticeable during overcast conditions, low-light winter months, or when solar irradiance is variable, ensuring your batteries receive a reliable charge when you need it most.
Designed specifically for 12V battery systems, the Votronic MPP 350 Duo supports solar arrays up to 350Wp with a maximum input voltage of 50V (Voc) and current up to 21A. Its high-frequency switching design achieves an efficiency exceeding 95%, minimising energy losses and maximising the usable power delivered to your battery bank.
Humidity-Proof Construction for Marine and Coastal Reliability
This Marine Version features a humidity-proof design, making it suitable for installation in environments where moisture and condensation are a concern, such as boats, coastal caravans, and motorhomes. The conformally coated electronics protect against corrosion and electrical faults caused by damp air, significantly reducing the risk of premature failure compared to standard controllers. Both the controller and any connected display must be installed inside the vehicle or vessel, away from direct water exposure, to maintain this protection.
Simultaneous Dual-Battery Charging with Intelligent Prioritisation
One of the standout features of the Votronic MPP Duo series is its ability to charge two independent battery banks simultaneously. The primary output delivers up to 25.5A to your house/service battery (BOARD I), while a secondary output provides up to 1A of support and trickle charging to your vehicle's starter battery (Start II). This ensures your engine battery remains topped up during storage or extended off-grid stays, preventing the inconvenience of a flat starter battery. Both outputs are protected against overcharging, reverse current, and overload.
Adaptive Charging Profiles for Lead-Acid and LiFePO4 Batteries
The controller features a sophisticated IU1oU2 charging characteristic with selectable profiles for various battery chemistries. It includes 3 pre-configured programs for lead-acid, gel, and AGM batteries, plus 5 dedicated programs for LiFePO4 (Lithium Iron Phosphate) batteries with integrated Battery Management Systems (BMS). The LiFePO4 profiles incorporate temperature-based protection, automatically adjusting charging parameters to safeguard the battery against extreme temperatures. For lead-acid batteries, an optional temperature sensor (Order No. 2001) enables voltage compensation, improving charge acceptance in cold weather and reducing gassing in high temperatures.
Key Features at a Glance
- MPPT technology boosts charging current by 10% to 30% versus standard controllers, especially in low-light conditions
- Dual-battery charging with 25.5A main output and 1A trickle charge for starter battery maintenance
- Humidity-proof electronics for reliable operation in marine and high-moisture environments
- Wide solar input range up to 350Wp, 50V Voc, and 21A for flexible panel configurations
- 8 selectable charging programs for lead-acid, gel, AGM, and LiFePO4 batteries with temperature protection
- AES refrigerator output automatically switches compatible Dometic/Electrolux fridges to 12V when excess solar power is available
- Integrated 30A blade fuse and comprehensive protection against overload, overheating, short circuit, and reverse polarity
- Plug-in ready for Votronic LCD Solar Computer S, VPC, or Bluetooth Connector for system monitoring
- EBL measurement output for compatibility with Schaudt Elektroblock displays (cable set Art. 2007 required)
- Automatic charging cable compensation corrects voltage drop for accurate battery charging
Smart Energy Management with AES Refrigerator Control
The built-in AES (Automatic Energy Selector) terminal intelligently switches compatible Dometic or Electrolux absorption refrigerators from gas to 12V operation when surplus solar energy is available. This maximises the use of free solar power, reducing gas consumption and extending your off-grid autonomy. An LED indicator clearly shows when the AES function is active.
Comprehensive System Monitoring and Integration
Stay informed about your solar system's performance with the controller's intuitive LED indicators, which display MPP operation, battery state of charge (>80%, Full), AES status, and low voltage warnings. For more detailed data, the controller is plug-in ready for the Votronic LCD Solar Computer S, VPC, or Bluetooth Connector, allowing you to monitor charging currents, battery voltage, and energy yields in real time. Additionally, the EBL measurement output enables integration with Schaudt Elektroblock systems, displaying solar current on your existing control panel (compatibility should be verified prior to installation).
Built to Last with Robust Protection Features
Safety and longevity are paramount in mobile installations. The Votronic MPP 350 Duo includes an integrated 30A blade fuse for circuit protection, along with electronic safeguards against overload, overheating, short circuit, and reverse battery connection. The on-board mains suppression filter ensures trouble-free parallel operation with other charging sources such as alternators, mains chargers, or generators. With an operating temperature range of -20°C to +45°C and CE/E-approval for vehicle use, this controller is built to perform reliably in Australian conditions.
Compact and Lightweight Design for Easy Installation
Measuring just 77 x 131 x 40 mm and weighing only 285 g, the Votronic MPP 350 Duo is easy to install in tight spaces typical of motorhome and marine electrical compartments. The clearly labelled terminals accept solar panel and battery connections with ease, and the included wiring diagram simplifies setup for both professional installers and experienced DIY users.
Upgrade Your Off-Grid Power System Today
Whether you're cruising the coast, exploring the outback, or living off-grid, the Votronic MPPT 25A Duo 350 Marine Solar Charge Controller delivers the efficiency, durability, and intelligent battery management you need. Order now to maximise your solar harvest and protect your batteries with advanced MPPT technology designed for the toughest environments.
SPECIFICATIONS
Specifications
| Application | Motorhomes, Caravans And Marine |
|---|---|
| Battery Voltage Lead / LiFePO4 | 12 V / 12.0...13.3 V |
| Solar Module Power (Pmax) | 50...350 Wp |
| Solar Module Current Max. | 21 A |
| Solar Module Voltage (Voc) Max. | 50 V |
| Charging Current On-board / Starter Battery Max. | 25.5/1.0 A |
| Charging Characteristic | IU1oU2 |
| MPP Charging Current Increase | 10 % to 30 % compared with conventional controllers |
| Efficiency | > 95 % |
| Switch Output AES Refrigerator | 12 V/0.2 A |
| Solar Computer S / VPC / Bluetooth Connector Connection | Plug-in Ready |
| Dimensions (L x W x H) | 77 x 131 x 40 mm |
| Weight | 285 g |
| Charging Programs For Lead-Acid/Gel/AGM | 3 |
| Charging Programs With Temperature Protection For Current LiFePO4 Complete Batteries With BMS | 5 |
| Ambient Temperature Range | -20 to +45 °C |
| Approvals | CE, E-Approval (EMC/Vehicle Directive) |
| Protection | Protection against overload, overheating, short circuit, reverse polarity |
| SKU: | Vot-11720 |
| Barcode: | 4250680000000 |
| Model #: | Vot-11720 |
| MPN: | Vot-11720 |
WARRANTY
VOTRONIC Warranty Policy
This warranty policy applies to VOTRONIC products supplied by us in Australia. VOTRONIC products supplied by us are covered by a 60 month warranty against defects in materials or manufacture, subject to the product being used, installed and operated correctly and in accordance with the manufacturer's instructions.
This warranty applies to the original end-user purchaser of the product, as evidenced by a valid proof of purchase, and is not transferable unless otherwise agreed in writing.
The benefits given by this warranty are in addition to other rights and remedies available under law.
Warranty Coverage and Periods
This warranty covers VOTRONIC products supplied by us, including charging devices, inverters, converters, monitoring devices, display devices and related accessories. The warranty periods for each product range are set out below.
| VOTRONIC Product Model Range | Warranty Length | Application / Notes |
|---|---|---|
| VOTRONIC Charging Devices | 60 months | Applies to VOTRONIC chargers, charging converters, solar charging controllers and related charging equipment where used as intended and within the product's rated specifications. |
| VOTRONIC Inverters and Power Devices | 60 months | Applies to VOTRONIC inverters, converters and related power electronics where correctly installed and operated within the product's technical ratings. |
| VOTRONIC Measuring and Display Devices | 60 months | Applies to VOTRONIC battery monitors, displays, tank level displays, computers and related monitoring devices where installed and used in accordance with the manufacturer's instructions. |
| VOTRONIC Accessories and Peripheral Devices | 60 months | Applies to VOTRONIC accessories and peripheral devices supplied by us and covered by the applicable manufacturer warranty. |
The warranty period begins on the date of purchase by the original end-user, as shown on the valid proof of purchase. A valid proof of purchase is required for all warranty claims.
Installer Responsibilities and System Design
VOTRONIC products are commonly installed, connected, configured or integrated into a broader electrical system, vehicle, vessel, caravan, motorhome or other operating environment. Once installed, the product may form only one component of a larger system.
We do not provide installation services unless expressly stated in writing, and we do not supervise or control installation practices carried out by dealers, installers, contractors or end-users. The installer, system designer, integrator, dealer or end-user is responsible for ensuring that the product is suitable for the intended application and is installed correctly.
Issues or damage arising from incorrect installation, poor system design, incorrect configuration, incompatible equipment, inadequate protection, unsuitable mounting, unsuitable environmental conditions or failure to follow the manufacturer's instructions are not product defects and are not covered by this warranty.
Appropriate Installation
All VOTRONIC products must be installed in accordance with the product manual, the manufacturer's installation instructions, applicable Australian Standards, relevant electrical, automotive, marine or industry standards, and recognised industry best practice.
The installer must ensure that the product is used in an appropriate environment and within its specified ratings. Improper, unsafe, unlicensed, sub-standard or non-compliant installation may void or limit warranty coverage.
System Compatibility
The installer or integrator is responsible for selecting and using compatible components. This includes ensuring compatibility with batteries, chargers, solar panels, regulators, alternators, inverters, wiring, fuses, circuit breakers, sensors, shunts, displays, power supplies, controllers and any other connected equipment.
Damage or underperformance caused by incompatible, incorrectly configured, undersized, oversized, unsuitable or improperly installed equipment is not covered by this warranty.
System-Wide Performance
Overall system performance depends on design, installation, configuration, usage, maintenance and environmental factors beyond the VOTRONIC product itself. This warranty covers the quality of the individual VOTRONIC product supplied by us only. It does not guarantee the performance of the broader electrical system into which the product is installed or integrated.
Issues such as insufficient charging, incorrect battery management, poor solar performance, nuisance faults, overheating, voltage drop, instability, intermittent operation, inaccurate readings or operational shortfalls caused by system design, installation or configuration are outside the scope of this warranty.
Installation Location and Environmental Suitability
The installer must ensure that VOTRONIC products are mounted, located, supported, ventilated and protected in a manner suitable for the installation environment.
Where relevant, the installer must allow for heat dissipation, ventilation, moisture exposure, dust, vibration, corrosion risk, aggressive battery gases, electrical clearance, mechanical loading, access for inspection and service, and protection from unsuitable environmental conditions.
Damage caused by unsuitable mounting, inadequate ventilation, moisture, dust, corrosion, aggressive battery gases, excessive heat, vibration, insufficient clearance, unsuitable substrate selection or other installation environment issues is not a manufacturing defect and is not covered by this warranty.
System Protection and Fault Isolation
The installer must incorporate suitable protective devices and design measures appropriate to the product and installation type. This may include correctly rated fuses, circuit breakers, isolators, over-current protection, over-voltage protection, low-voltage protection, reverse polarity protection, surge protection, correct cable sizing and other protective devices required by standards or best practice.
The installer is responsible for ensuring that a fault or failure in one component does not cause cascading damage to other components. Damage to VOTRONIC products caused by inadequate system protection, poor fault isolation, incorrect protection settings or missing safety devices is not covered by this warranty.
Service Accessibility Requirement
Products must be installed in a manner that allows reasonable access for inspection, testing, servicing, removal and replacement. We are not responsible for additional labour, structural modification, access equipment, removal of fixtures, cabinetry, panels, flooring, trim, sealants, adhesives or other costs arising from installation methods that restrict reasonable access to the product.
Installation Documentation
We may require documentation of the installation when assessing a warranty claim. This may include photos of the product in its installed location, wiring diagrams, system layout, serial numbers, details of connected equipment, installer details, commissioning records, service history, fault logs, operating settings and maintenance records.
Failure to provide reasonable installation evidence may limit our ability to assess the claim.
Independence of Dealers and Installers
Dealers, resellers, installers and contractors act independently and are not agents, employees or representatives of VOTRONIC or us unless expressly agreed in writing. We are not responsible for the acts, omissions, workmanship, advice, representations, installation practices or system design decisions of independent dealers, resellers, installers, contractors or third parties.
What This Warranty Does Not Cover
This warranty covers manufacturing defects or failures of the product arising from normal use in accordance with the manufacturer's instructions. It does not cover any failure, damage, performance issue, deterioration or loss caused wholly or partly by external factors, misuse, incorrect installation or circumstances outside the manufacturer's control.
- Incorrect installation or wiring
- Incorrect product selection or application
- Use outside the product's intended purpose
- Operation outside the product's rated technical specifications
- Incorrect voltage, current, load, charging profile or configuration
- Improper operation, misuse, abuse or neglect
- Physical impact, accidental damage or mechanical damage
- Unauthorised modification, tampering, disassembly or repair
- Service work carried out by a third party not authorised by the manufacturer
- Use with incompatible, incorrectly rated or improperly configured third-party components
- Damage caused by inadequate fusing, circuit protection, isolation or system protection
- Damage caused by moisture, dust, corrosion, aggressive battery gases or unsuitable installation environments
- Damage caused by excessive heat, inadequate ventilation or installation in an unsuitable location
- Damage caused by vibration, movement, poor mounting or inadequate support
- Normal wear and tear, cosmetic deterioration or gradual degradation consistent with normal use
- Failure to carry out reasonable inspection, cleaning, maintenance or servicing where required
- Products with removed, altered, damaged or illegible serial numbers, rating labels or identification markings
- Products purchased second-hand, from unauthorised channels, auction sites, liquidation sales or grey-market sources
- Labour costs for removal, replacement, reinstallation or diagnosis
- Freight, travel, call-out costs or access costs unless otherwise required by law
- Products not returned for assessment when reasonably required
- Consequential or incidental loss, including damage to other equipment, downtime, loss of use, loss of revenue or economic loss, to the extent permitted by law
Warranty Assessment and Remedy
If a VOTRONIC product supplied by us is found to be defective within the applicable warranty period, we will, at our discretion, arrange a repair, replacement, store credit, refund or another appropriate remedy, depending on the nature of the fault and the requirements of Australian Consumer Law.
Products may need to be returned for assessment before a warranty claim can be approved. Where required, the product must be returned with dated proof of purchase, product details, serial number if available, installation information and a clear description of the fault.
If the product is required to be returned to VOTRONIC or another nominated assessment location for inspection or repair, a return authorisation process may be required before the product is sent. Products sent without the required return authorisation or documentation may not be processed.
Labour costs for removing, replacing, reinstalling or diagnosing a product are not covered by this express warranty unless otherwise required under Australian Consumer Law.
Making a Warranty Claim
If you suspect a fault with a VOTRONIC product supplied by us, do not immediately remove or uninstall the product unless it is unsafe to leave it in place or unless authorised as part of the warranty process. Premature removal may cause further damage or make it difficult to determine the original cause of the issue.
- Contact us: Contact us with your dated proof of purchase, product model, serial number if available, and a description of the fault.
- Provide product and installation information: We may request installation photos, wiring details, connected equipment details, operating settings, fault codes, measurements or service history to assist with assessment.
- Assessment and troubleshooting: We may ask for safe checks, photos, testing information or other details to determine whether the issue appears to be a product fault or is caused by installation, configuration, connected equipment, environment or misuse.
- Return for inspection if required: If the fault cannot be confirmed remotely, the product may need to be returned for inspection, testing, repair or replacement assessment. Return instructions will be provided where required.
- Outcome: If the product is confirmed to be faulty and covered by this warranty, we will advise the available remedy. If the product is found not to be faulty, or the issue is caused by an excluded factor, the claim may be rejected.
Remedies Under Warranty
If a defect covered by this warranty is confirmed, we may provide one or more of the following remedies, subject to the circumstances of the claim and the requirements of Australian Consumer Law:
- repair of the product;
- replacement of the product;
- store credit;
- refund;
- supply of replacement parts; or
- another appropriate remedy required by law.
Repair or replacement under this warranty does not restart or extend the original warranty period. The warranty continues from the original purchase date.
Manufacturer Support
VOTRONIC may provide repair or assessment services through its own service process. Where available, we may assist customers in contacting the manufacturer or arranging assessment, but any manufacturer service is subject to VOTRONIC's own process, requirements and continued availability.
Australian Consumer Law
This warranty is in addition to other rights and remedies available at law. Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are entitled to a replacement or refund for a major failure and compensation for any other reasonably foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if the goods fail to be of acceptable quality and the failure does not amount to a major failure.















































