MultiPlus-II - The Next Generation Inverter/Charger for Professional Marine, Vehicle, and Off-Grid Systems,PMP122305010

About this product

The MultiPlus-II takes the proven MultiPlus platform and refines it for modern energy systems. It is a multifunctional inverter/charger with two AC outputs, a powerful true sine wave inverter, an adaptive battery charger, and a high-speed AC transfer switch - all in a compact casing that fits where space is tight and reliability is non-negotiable.

The MultiPlus-II is suitable for professional marine, yachting, vehicle, and land-based off-grid systems. It also provides the isolation and redundancy required for ESS (Energy Storage System) setups, making it equally at home in grid-connected self-consumption installations.

Available models cover 3000VA, 4kVA, 4.5kVA, 5000VA, 6.5kVA, 8000VA, 10000VA, and 15000VA. Separate product pages cover the MultiPlus-II GX and MultiPlus-II 2x120V variants, which address specific monitoring and North American split-phase requirements respectively.

What Sets the MultiPlus-II Apart

The MultiPlus-II combines the functions of the MultiPlus and the MultiGrid, offering all the features of the MultiPlus plus an optional external current sensor that extends the PowerControl and PowerAssist function to 100A depending on the model. This makes it possible to measure the current to or from the mains in grid-parallel topologies where the internal current transformer cannot be used.

Uninterrupted AC Power (UPS Function)

In the event of a grid failure, or when shore or generator power is disconnected, the inverter within the MultiPlus-II is automatically activated and takes over the supply to the connected loads. This happens so fast - less than 20 milliseconds - that computers, navigation equipment, and other sensitive electronics continue to operate without disruption.

PowerControl - Maximum Use of Limited AC Power

The MultiPlus-II prevents overload of a limited AC source, such as a generator or shore power connection. A maximum generator or shore current can be set, and the MultiPlus-II then takes other AC loads into account, using only the surplus current for battery charging. This ensures the generator or shore supply is never overloaded.

PowerAssist - Extended Use of Generator or Shore Current

PowerAssist takes the principle of PowerControl further. Where peak power is required only for short periods, the MultiPlus-II compensates for insufficient AC mains or generator power with energy drawn from the battery. When the load reduces, the spare power is used to recharge the battery. This enables the system to handle peak loads well beyond the capacity of the connected AC source without tripping breakers.

Two AC Outputs

The main AC output features no-break functionality. Upon generator or shore disconnection, the MultiPlus-II takes over the load supply in under 20 milliseconds, ensuring uninterrupted operation of connected equipment. The second AC output is active only when AC is available on the input. Loads that should not discharge the battery - such as a water heater or air conditioning - can be connected to this output, allowing critical loads to remain powered during outages while non-essential high-power loads are automatically shed.

ESS: Energy Storage Systems - Dynamic Energy Management

The robust MultiPlus-II is a key component in a Victron Energy Storage System. The Dynamic ESS feature takes ESS to the next level by automatically switching between - or combining - grid, battery, and solar energy based on live pricing, predicted energy use, and solar yield, ensuring the system is always consuming the cheapest energy available.

Parallel and Three-Phase Operation - Virtually Unlimited Power

Up to six MultiPlus-II units can operate in parallel to achieve higher power output. Six 48/5000/70 units, for example, provide 25kW / 30kVA output power with 420A charging capacity. Three units of the same model can be configured for three-phase output. Up to six sets of three units can be parallel connected for a 75kW / 90kVA inverter with more than 1200A charging capacity. For parallel and three-phase setups, a multi-unit system can be created with one GX unit and other non-GX units.

Adaptive Charging and Battery Care

The MultiPlus-II combines speed with efficiency through a smart adaptive charging algorithm that extends battery life. The charger features a four-stage adaptive charge profile - bulk, absorption, float, and storage - with a supplied battery temperature sensor. The 12V and 24V models include a trickle output intended for maintenance charging of a starter battery, using a simple circuit with a current limiter and diode to allow continuous 4A charging from the main battery to the starter battery.

Remote Monitoring and Control

When coupled with a GX device (e.g., Cerbo GX or Ekrano GX), the MultiPlus-II and its associated system can be monitored and controlled locally over LAN or remotely via the internet from anywhere in the world using the free VRM app and VRM portal website. Access can be from a phone, tablet, laptop, or PC for multiple operating systems. From adjusting the MultiPlus-II to auto-starting a backup generator, there is no end to the level of control.

Comprehensive Protection

The unit incorporates full protection against output short circuits, overload, battery over-voltage, battery under-voltage, over-temperature, AC on inverter output, and excessive input voltage ripple.

Specifications

Product Dimension Drawing

Tailored System Solution - Wysher × Victron Energy Across the MultiPlus-II Range

The MultiPlus-II is not a one-size-fits-all device. The same product line covers eight power classes, from the 3000VA compact unit for mobile and marine installations to the 15000VA flagship for industrial-scale off-grid and ESS applications. Typical applications across the range include:
Yachts and professional marine installations, where the MultiPlus-II provides isolation and redundancy for navigation, communication, and onboard appliances. A 50ft catamaran can run entirely without a generator, using a 15kVA 48V MultiPlus-II alongside an isolation transformer for shore power, plus two parallel 48V 5000VA units for the 120V system - powering air conditioning, water heaters, and all onboard loads.
Off-grid homes and remote cabins, where the MultiPlus-II pairs with MPPT solar charge controllers and a lithium battery bank, with the optional external current transformer extending PowerControl and PowerAssist to 100A for larger generator and grid inputs.
Grid-connected ESS installations, where the MultiPlus-II provides the isolation and redundancy required for self-consumption and backup power, with Dynamic ESS automatically optimising between grid, battery, and solar based on live pricing and predicted energy use.
Mobile workshops and specialty vehicles, where a single MultiPlus-II handles shore charging, inverter supply, transfer switching, and high-start-up loads in one compact enclosure.
Large off-grid estates and commercial backup power, where multiple 10000VA or 15000VA units operate in parallel or three-phase configuration to deliver scalable capacity with centralised monitoring.
Based on the Victron Energy architecture, Wysher integrates MultiPlus-II inverter/chargers with LiFePO₄ battery banks, MPPT solar charge controllers, and GX monitoring devices to deliver a complete, intelligent energy solution across every power class. Through careful system engineering, we ensure:
✓ Seamless automatic switchover between shore and battery power, leveraging the MultiPlus-II's UPS-grade transfer across the entire range
✓ Dynamic load sharing via PowerAssist to prevent inlet breaker trips on weak or limited shore supplies, with optional external current sensing up to 100A
✓ Optimised battery charging with adaptive four-stage profiles and temperature compensation
✓ Scalability from a single 3000VA unit to parallel or three-phase configurations reaching 75kW / 90kVA
✓ Full remote visibility and control via VRM, with GX-compatible integration for proactive management and generator auto-start