Victron Energy MultiPlus-II 12/4k/160-50 120V Inverter/Charger (UL 458)

If you want serious AC output but you’re staying on a 12V system, this is the top of the line. The MultiPlus-II 12/4k/160-50 is the highest-output 12V MultiPlus-II inverter/charger in Victron’s 120V range — 3,400 W of continuous power (4,000 VA nominal) and a 160 A charger, without stepping the system up to 24V. That matters when the wiring, the battery bank, and the rest of the DC architecture are already built around 12V and you’d rather add capability than re-engineer the whole platform.

Like every MultiPlus, it’s three things in one enclosure: a true sine wave inverter, a smart multi-stage battery charger, and a high-speed AC transfer switch. Where it separates itself is headroom — more inverter output and the strongest charge current Victron offers at 12V, so bigger loads run and a depleted bank comes back faster.

3,400W continuous, 6 kW on tap

Continuous output is 3,400 W at 25°C, holding 3,100 W at 40°C and 2,400 W at a hot 65°C — real numbers under real heat, not a headline figure that collapses the moment the enclosure warms up. Peak output reaches 6,000 W for 2 seconds, with time-limited cold-start ratings of 4.0 kW for an hour and 4.5 kW for 30 minutes. That surge headroom is what starts hard-starting loads and rides out inrush without nuisance shutdowns. It’s a pure sine wave output, so sensitive electronics, motors, and compressors see clean power.

160A battery charger that actually recovers a lithium bank

The built-in charger pushes up to 160A — the highest in the 12V lineup — using Victron’s adaptive multi-stage profile with absorption, float, and storage stages, plus a battery temperature sensor input. On a large LiFePO4 house bank, that’s the difference between a full recharge in a single shore or generator window and one that drags into a second. Charge voltages are configurable for lithium and lead-acid chemistries alike, and the whole profile is set in software rather than jumpers.

PowerControl and PowerAssist: never trip the source

Set a maximum input current and PowerControl keeps the unit inside it, prioritizing loads and using whatever’s left for charging so a limited generator or shore pedestal never overloads. PowerAssist goes a step further — when a load briefly exceeds what the source can deliver, the MultiPlus blends in battery power to cover the peak, then quietly replenishes the bank when demand falls. The result is a small AC source that behaves like a much bigger one.

Two AC outputs and no-break backup

One AC input, two AC outputs. The main output has no-break functionality — when shore, grid, or generator power disappears, the MultiPlus-II takes over the load in under 20 milliseconds, fast enough that computers, controls, and other electronics never notice. The second output stays live only while input power is present, so non-critical loads that shouldn’t drain the battery are automatically shed the moment the source drops. It’s uninterruptible power and load management from a single unit.

Built to scale

One unit today doesn’t lock you in. Up to six units run in parallel for higher output, two matched units combine for 120/240 V split-phase, and three configure for three-phase — and you can parallel multiple sets of three per phase. The system grows without being replaced.

Monitored, configured, and connected

Everything is set through VictronConnect or VEConfigure with a MK3-USB interface — no dip switches, no guesswork. Add a Cerbo GX or Ekrano GX and the system reports to the free VRM portal, so you can watch state of charge, loads, and charge status and change settings from anywhere. Two general-purpose comm ports, a programmable relay, remote on/off, and the VE.Bus port tie it cleanly into a full Victron ecosystem and into lithium battery management.

Built to last

UL 458 listed and built in a n IP22 enclosure finished in Victron’s signature blue, it’s rated for a -40°C to +60°C operating range with fan-assisted cooling and protected against short circuit, overload, over- and under-voltage, over-temperature, and ripple. This is equipment specified for permanent installation, not a portable stopgap.

Who it’s for

The 12/4k/160-50 works anywhere a high-output 12V system needs clean, uninterruptible AC and fast charging — professional marine and yachting, mobile and vehicle builds, land-based off-grid, and backup power. If the bank is 12V and the AC load demand is high, this is the Multi that keeps the platform at 12V while giving it the output of a much larger system.