Victron MultiPlus-II 12/3000/120-50 120V Inverter Charger (UL 458)

The Victron MultiPlus-II 12/3000/120-50 120V (UL 458) is a compact inverter/charger designed for mobile, marine, and off-grid electrical systems that require reliable 120V AC power from either shore, generator, or battery sources. It combines a pure sine wave inverter, a high-performance battery charger, and an automatic transfer switch in a single enclosure, making it an efficient all-in-one solution for modern onboard energy systems.

When shore or generator power is available, the unit passes AC power through to connected loads while simultaneously charging the battery bank. If the external AC source is disconnected, the inverter activates automatically in under 20 milliseconds, maintaining uninterrupted power for sensitive electronics such as navigation equipment, communication systems, and onboard computers. This seamless transition ensures dependable operation in demanding marine and vehicle environments.

The integrated transfer switch supports up to 50A of passthrough current, allowing the system to handle typical North American 120V service connections with ease. Dual AC outputs enable prioritization of critical loads, automatically disconnecting non-essential circuits when external power is unavailable to help preserve battery capacity.

Designed for flexibility and long-term system growth, the MultiPlus-II supports parallel and three-phase configurations when higher power is required. It is fully compatible with LiFePO4 and other battery technologies and integrates with Victron GX devices for remote monitoring and control through the VRM portal. This makes it a dependable foundation for scalable energy systems in boats, RVs, service vehicles, and off-grid installations.

Features

Split-phase passthrough capability

Accepts both legs of a 120/240V split-phase input and delivers full passthrough power to onboard loads while charging batteries. This allows the system to support standard 50A shore connections without sacrificing performance or charging capacity.

Smart single-phase fallback operation

When connected to a single 120V source, the inverter automatically combines L1 and L2 outputs so both sides of the panel remain energized. This keeps critical circuits operational even at reduced dock power availability.

PowerAssist load boosting

PowerAssist supplements limited shore or generator input using battery power during peak demand periods. This prevents nuisance breaker trips and allows smaller generators to run larger loads safely.

Fast UPS transfer switching

Automatic transfer to inverter mode occurs in less than 20 milliseconds if shore or generator power is lost. Sensitive electronics such as navigation systems, computers, and networking equipment continue operating without interruption.

Dual AC outputs with load prioritization

The primary output supplies critical loads continuously, while the secondary output disconnects automatically when shore power is unavailable. This prevents unnecessary battery discharge from non-essential equipment.

Remote monitoring with Victron VRM

When paired with a Cerbo GX or other GX device, the system can be monitored and controlled locally or remotely through the VRM portal. Users can adjust settings, track performance, and manage energy usage from anywhere.

Specifications

Datasheets and Manuals

Datasheet

Product Manual