Victron Energy MultiPlus-II Inverter Charger 120V

The Victron MultiPlus-II is the inverter/charger that runs the AC side of most professional marine, RV, and off-grid systems built today. It inverts your battery bank to clean 120 V AC, charges from shore or generator with an adaptive 4-stage profile, and uses PowerAssist to boost a small shore connection with battery power — all from a single ruggedized UL-listed unit available from 3,000 VA to 5,000 VA across 12V, 24V, and 48V banks.

Available in eight variants spanning 12V / 24V / 48V system voltage, 3000, 4000, or 5000 VA continuous output, 35 A to 160 A charger current, with UL 458 (marine/RV) or UL 1741 (grid-tie / ESS) listing where the install requires it. All variants are pure sine wave with built-in anti-islanding, 20 ms transfer time, and VE.Bus communication to a Cerbo GX or Ekrano GX.

Available versions

Choose your battery voltage, continuous output, charge current, and UL listing from the Size selector above. SKUs follow the pattern PMP + voltage + power + charger amps + revision.

• 12/3000/120-50 (UL 458) — 12V / 3000 VA / 120 A charger. Mid-size RVs, Class B vans, trailerable boats on a 12V lithium house bank.
• 12/4000/160-50 (UL 458) — 12V / 4000 VA / 160 A charger. The 12V power step-up: 3,400 W continuous and the strongest 12V charger in the range, for bigger AC loads and faster bank recovery without moving to 24V.
• 24/3000/70-50 (UL 458) — 24V / 3000 VA / 70 A charger. Cruising sailboats and Class A motorhomes on a 24V system.
• 24/5000/120-95 — 24V / 5000 VA / 120 A charger, no UL. Liveaboard cats and big RVs with AC, induction, and full galley load.
• 48/3000/35-50 — 48V / 3000 VA / 35 A charger, no UL. Off-grid cabins and tiny homes (1.5–3 kW solar).
• 48/3000/35-50 (UL 1741) — same chassis, UL 1741 anti-islanding for US grid-tie / ESS.
• 48/5000/70-95 — 48V / 5000 VA / 70 A charger, no UL. Larger off-grid homes and liveaboards (3–5 kW solar). Available while Victron's stock lasts.
• 48/5000/70-95 (UL 1741) — same chassis, UL 1741 for grid-tie / ESS installs.

Not sure which fits your bank? Get a custom quote or book a system consultation and our Advisors will spec the inverter/charger, batteries, MPPTs, fusing, and cable sizes for your system.

Who the MultiPlus-II is built for

• Cruising boats and sailboats — the 12V and 24V variants are the standard inverter/charger pairing for a lithium house bank, a shore inlet, and a small generator. PowerAssist lets a 30 A shore cord drive a 3,500 W induction cooktop on a hot afternoon without tripping the dock.
• Class A motorhomes and overland builds — the 24V/3000 VA and 24V/5000 VA variants handle full-rig AC loads from a 200–400 Ah lithium bank. Pair the 5000 VA with a residential refrigerator, microwave, and roof-air running together.
• Big 12V systems that want to stay 12V — the 12/4000/160-50 gives a 12V rig 3,400 W of continuous AC and a 160 A charger, covering induction cooking or a second air conditioner without a system-voltage change.
• Off-grid cabins, tiny homes, and liveaboards — the 48V variants are the off-grid favorite. Pair a 48/3000 with a 200 Ah 48V LiFePO4 bank and a 1.5–3 kW solar array; pair the 48/5000 with a 300–400 Ah bank and a 3–5 kW array for whole-home off-grid.
• Energy Storage Systems (ESS) — UL 1741 variants run a Victron grid-tie ESS install: solar plus battery plus grid, with self-consumption, peak-shaving, or full grid backup all configurable from VictronConnect or VRM.
• Electric propulsion boats — the 48V variants run alongside an electric inboard, saildrive, or pod drive (Oceanvolt, ePropulsion E-Series, etc.) on the same 48V house/propulsion bank. The MultiPlus-II handles all the AC side: shore charging the propulsion bank, inverting house AC loads underway and at anchor, and PowerAssist when the dock breaker can't keep up.

Why this is the MultiPlus-II, not just another inverter/charger

Pure sine wave inverter that switches over in 20 ms

When shore power drops out or the generator runs out of fuel, the MultiPlus-II takes over from the battery bank in 20 milliseconds — fast enough that a desktop, a network switch, or a residential refrigerator never sees the transition. That's UPS-grade behavior on a marine/RV/off-grid inverter, and it's the reason this is the unit professional installers wire as the AC source for any sensitive load.

PowerControl and PowerAssist on every variant

PowerControl caps the current drawn from a shore inlet or generator so you can pull into a 15 A dock without tripping the breaker — the MultiPlus-II throttles charging back automatically. PowerAssist goes the other direction: when a transient load (induction burner, microwave, AC compressor start) would exceed the shore cord rating, the inverter pulls the extra current from the battery bank in parallel. A 30 A shore cord effectively becomes a 50 A cord at peak.

Adaptive 4-stage charger with lithium and AGM profiles

Bulk, absorption, float, and storage stages with variable absorption time. The charge profile is fully programmable for lead-acid, AGM, gel, or LiFePO4 banks over VictronConnect (with an MK3-USB) or directly from a connected GX device. Max charge current ranges from 35 A (48/3000) up to 160 A (12/4000) by variant — the 120–160 A models recover a 300 Ah lithium bank from a deep cycle in about three hours of bulk charging from generator or shore. A battery temperature sensor ships with the unit, and VE.Smart Networking pulls bank-side voltage and temperature from a Smart Battery Sense or SmartShunt so the charge profile reacts to true bank conditions rather than charger output.

VE.Bus to a Cerbo GX or Ekrano GX for full system visibility

Wire the MultiPlus-II to a Cerbo GX or Ekrano GX over VE.Bus and the GX device shows live AC input / output, battery voltage and current, charge state, and inverter load on a touchscreen and in the free VRM Portal — readable from anywhere with an internet connection.

Two units for 120/240 V split-phase, three for three-phase

Most North American RVs with 50 A service and most residential off-grid builds need 120/240 V split-phase AC, not single-phase 120 V. Wire two MultiPlus-IIs of the same variant in parallel on a single VE.Bus and you get the full split-phase output (one unit per leg) at the combined VA rating — the standard pairing for a 50 A RV inlet, a residential ESS, or a liveaboard with a 240 V well pump or dryer. Three units gives you a three-phase 18 kW system for larger off-grid setups. Up to six units total run on a single VE.Bus. A Cerbo GX (or any GX device) handles the configuration; all units must be the same model and variant.

ESS and grid-tie certified on UL 1741 variants

The 48/3000/35-50 120V (UL 1741) variant carries the anti-islanding certification required for grid-tied solar installs in most US jurisdictions. Combined with a SmartSolar MPPT and a lithium bank, it runs a full Energy Storage System — self-consumption from solar, peak-shaving against time-of-use rates, or seamless grid-backup when utility power drops.

External 100 A current sensor for shared circuits

An optional 100 A external AC current sensor lets the MultiPlus-II measure total current on a shared circuit (e.g., when the inverter shares a sub-panel with non-MultiPlus loads), so PowerControl and PowerAssist react to actual circuit demand rather than just the inverter's own pass-through. This extends PowerControl/PowerAssist measurement up to 100 A — useful on grid-parallel and self-consumption ESS installs. Ordered separately.

Full technical specifications

AC output (inverter mode)

• Output voltage: 120 V AC ±2%
• Output frequency: 60 Hz ±0.1% default; 50 Hz user-selectable via VEConfigure (useful for the rare 50 Hz / 120 V markets such as parts of Japan)
• Wave form: true pure sine wave
• Continuous output power (3000 VA variants): 3000 VA — 2400 W @ 25 °C, 2200 W @ 40 °C, 1700 W @ 65 °C
• Continuous output power (12/4000 variant): 4000 VA — 3400 W @ 25 °C, 3100 W @ 40 °C, 2400 W @ 65 °C
• Continuous output power (5000 VA variants): 5000 VA — 4000 W @ 25 °C, 3700 W @ 40 °C, 3000 W @ 65 °C
• Peak power: 5500 W (3000 VA variants) / 9000 W (5000 VA variants). The 12/4000 peaks at 6000 W for 2 s, plus time-limited cold-start power of 4.0 kW for 1 h and 4.5 kW for 30 min
• Maximum efficiency: 93% (12V/3000 and 12/4000), 94% (24V/3000), 95% (48V/3000 and 24V/5000), 96% (48V/5000)
• Zero-load power consumption: 11–13 W (3000 VA) / 18 W (12/4000) / 15–24 W (5000 VA), dropping to 7–11 W in AES mode and 2–4 W in Search mode
• Transfer time on shore loss: < 20 ms (UPS-grade)

AC input

• Input voltage range: 90–140 V AC, 55–65 Hz
• Transfer switch capacity: 50 A (3000 VA and 12/4000 variants) / 95 A (5000 VA variants)
• Maximum AC input current (PowerControl, user-set via VictronConnect/VEConfigure): up to the transfer switch rating
• External AC current sensor (optional, ordered separately): 100 A — extends PowerControl and PowerAssist measurement to shared circuits up to 100 A
• Anti-islanding: built-in (UL 1741 variants certified for US grid-tie)

Charger output

• Charge profile: 4-stage adaptive (bulk / absorption / float / storage) with variable absorption time
• Charge voltage absorption: 14.4 V (12V models) / 28.8 V (24V models) / 57.6 V (48V models)
• Charge voltage float: 13.8 V / 27.6 V / 55.2 V
• Storage mode: 13.2 V / 26.4 V / 52.8 V
• Maximum charge current: 160 A (12/4000), 120 A (12/3000 and 24/5000), 70 A (24/3000 and 48/5000), 35 A (48/3000)
• Battery temperature sensor: included; also supports VE.Smart Networking with Smart Battery Sense for wireless bank-side voltage and temperature
• Battery chemistry compatibility: flooded lead-acid, AGM, gel, LiFePO4 (lithium) — profile fully programmable

AC OUT-2 (auxiliary output)

• Live only when AC is present on the input — switches off automatically when shore/generator power is lost
• Rating: 32 A (3000 VA and 12/4000 variants), 43 A (24V/5000), 48 A (48V/5000)
• Typical use: water heaters, air conditioning, or other loads that shouldn't run from the battery bank

DC starter-battery trickle (12V and 24V variants only)

• 4 A continuous trickle from the main (house) battery to a separate starter battery
• Diode-isolated — charges only, never draws
• Available on the 12/3000/120-50 and the 24/3000/70-50 + 24/5000/120-95 variants. The 48V models do not include this output.

System and communication

• VE.Bus port for connection to a Cerbo GX, Ekrano GX, another MultiPlus-II (parallel, split-phase, or three-phase), Digital Multi Control panel, or VE.Bus Smart dongle
• Two general-purpose communication ports (e.g., lithium-battery integration)
• Remote on/off input
• Programmable relay: AC rating 120 V / 4 A; DC rating 4 A up to 35 V DC, 1 A up to 60 V DC. Settings: general alarm, DC undervoltage, or genset start/stop
• MK3-USB interface (sold separately) for direct VictronConnect / VEConfigure access from a PC
• VE.Bus Smart dongle (sold separately) for VictronConnect over Bluetooth, plus battery voltage and temperature sensing
• Up to 6 MultiPlus-IIs in parallel, or wired as three-phase, on a single VE.Bus — and up to 6 sets of three units in parallel per phase for very large installs (75 kW / 90 kVA total)

Protection

• Output short circuit
• Overload
• Battery voltage too high or too low
• Temperature too high
• 120 V AC on inverter output (back-feed)
• Input voltage ripple too high

Enclosure and environment

• Material and color: steel, blue (RAL 5012)
• Protection category: IP22 (dry-mount — install in a vented, dry compartment)
• Operating temperature: -40 to +60 °C (-40 to +140 °F), fan-assisted cooling
• Humidity (non-condensing): max 95%
• Battery connection: M8 bolts (the 12/3000 and 12/4000 use 2×2 M8 bolts — two positive, two negative)
• AC connection (max wire size): 13 mm² (6 AWG) on 3000 VA and 12/4000 variants; 35 mm² (2 AWG) on 5000 VA variants

Dimensions and weight (per variant)

Standards and certifications

• Safety: EN-IEC 60335-1, EN-IEC 60335-2-29, CSA 22.2 107.1-16
• UL listings (per variant):
  • UL 458 (marine/RV) — 12/3000/120-50 (UL), 12/4000/160-50, 24/3000/70-50 (UL)
  • UL 1741 (grid-tie / ESS, anti-islanding) — 48/3000/35-50 (UL 1741), 48/5000/70-95 (UL)
  • No UL listing — 24/5000/120-95, 48/3000/35-50, 48/5000/70-95. (The non-UL 48/5000 is a current Victron production model that will be discontinued once their stock sells through; available now while supplies last.)
• Emission and immunity: EN 55014-1, EN 55014-2, EN-IEC 61000-3-2, EN-IEC 61000-3-3, IEC 61000-6-1, IEC 61000-6-2, IEC 61000-6-3
• Marine practice: ABYC E-11 (we follow this on all marine installs)

All spec values above are taken from the Victron MultiPlus-II 120 V datasheet (current revision, including the 12/4000/160-50). The full datasheet and manual are in Manuals & Datasheets below on this page.

Recommended accessories

• Cerbo GX MK2 or Ekrano GX — system controller and VE.Bus monitor for live VRM data
• SmartShunt or BMV-712 Smart — precise battery state-of-charge over VE.Direct + VE.Smart Networking
• MK3-USB interface — for direct VictronConnect / VEConfigure access from a laptop
• Lynx Distributor + Class T or MEGA battery fuse — DC bus and battery-side fusing per ABYC E-11
• Victron SmartSolar MPPT — pair with the MultiPlus-II to build a full ESS system
• Compatible lithium banks from Victron, Epoch, and MG Energy Systems

Installation and sizing help

Wiring a MultiPlus-II isn't difficult, but cable sizing, battery-side fusing, AC inlet rating, and bonding to the boat / vehicle ground all need to match the variant you choose. A note on what ships from us vs. what's sourced locally: VE.Bus communication cables, MPPT and solar PV cables, and DC distribution components (Lynx Distributor, fuses, fuse holders) all ship from our Seattle warehouse. High-current battery cables aren't something we stock — AWG sizing depends on the bank-to-inverter run length, so most installers cut these to length locally or have them fabricated by a marine cable shop.

Battery cable and DC fuse sizing (from the Victron manual)

Use copper cable rated for 90 °C (194 °F). Cable sizes are per Victron's installation manual; size up where local code or longer runs require. (Victron hasn't yet published manual cable-sizing rows for the new 12/4000/160-50 — our Advisors can size that run with you.)

"2×" means two positive cables and two negative cables run in parallel. Don't route battery cables in a closed conduit.

Location and ventilation

• Dry, well-ventilated compartment, as close to the batteries as practical to minimize cable losses
• At least 10 cm (4 in) clearance around the unit for cooling airflow
• Never install the unit directly above the batteries — battery off-gassing corrodes the unit
• Wall-mount to a solid surface rated for the variant's weight (see Dimensions and weight)
• If integrating with a generator in a hybrid-genset enclosure, shock mounts are mandatory — chosen for the genset's vibration frequency and the unit's weight

Free sizing references

• Victron Wiring Unlimited — the canonical reference for sizing DC and AC sides of a Victron system.
• Our AWG-to-Metric Conversion chart for sizing battery and inverter cables.
• The full MultiPlus-II installation manual is in Manuals & Datasheets below — wiring diagrams, installation procedure, and protection notes.

If you want a second set of eyes on your install or your bank pairing, our ABYC-certified Advisors do system consultations and full custom quotes. Email support@bluemarine.com or call (800) 628-6306.

Care and maintenance

The MultiPlus-II is designed to be a low-maintenance unit. Per Victron's manual: check all battery and AC connections once a year for tightness and corrosion, keep the enclosure clean and dry, and avoid environments with oil, soot, or condensing humidity. Internal fuses aren't user-replaceable — if a fuse blows, the unit needs to go to an authorized service center for diagnosis. We handle warranty intake at support@bluemarine.com.

Frequently asked questions

What's the difference between the MultiPlus and the MultiPlus-II?

The MultiPlus-II combines the original MultiPlus with the MultiGrid — it has the same inverter/charger functions as the MultiPlus, plus built-in anti-islanding, an external current transformer option for monitoring shared circuits, and a long list of grid-tie country approvals. If you're specifying a new install today, the MultiPlus-II is the current generation.

Will the MultiPlus-II charge LiFePO4 (lithium) batteries?

Yes. The charger is fully programmable via VictronConnect (with an MK3-USB) or from a connected GX device. Pre-configured profiles exist for AGM, gel, flooded lead-acid, and lithium; everything else can be set with custom absorption / float / storage voltages and currents. For BMS integration, wire the BMS load-disconnect signal to the MultiPlus-II's remote on/off port.

Which variant do I pick for a 30-foot sailboat?

The 12/3000/120-50 120V (UL) is the most common pairing for a 30–36 ft sailboat running a 200–400 Ah, 12V lithium house bank with a 30 A shore inlet and a small generator. If you're running a 24V system, the 24/3000/70-50 120V (UL) is the equivalent. For air conditioning or induction cooking that pulls more than 3 kW continuous, look at the 12/4000 (to stay on 12V) or the 5000 VA variants.

Do I need a Cerbo GX with the MultiPlus-II?

Not strictly. VictronConnect over an MK3-USB lets you configure and monitor the MultiPlus-II directly. A Cerbo GX or Ekrano GX adds remote access through VRM Portal, a touchscreen front-panel display, and integration with your MPPTs, BMV, and shunts so the whole system reports through one device.

Can I parallel two MultiPlus-IIs for 120/240 V split-phase?

Yes — that's the most common parallel configuration in North America. Two MultiPlus-IIs of the same variant in parallel on a single VE.Bus deliver 120/240 V split-phase AC (one unit per leg) at the combined VA rating — the standard requirement for a 50 A RV inlet, a residential off-grid build, or a liveaboard running a 240 V well pump, dryer, or electric range. Three units gives you a three-phase 18 kW system, and up to six total run on a single VE.Bus for very large installs. All units must be the same model and variant, and a Cerbo GX (or any GX device) is required for configuration and monitoring.

What's the difference between the UL 458 and UL 1741 variants?

UL 458 covers safety for marine and RV inverter/chargers operating from a battery bank. UL 1741 covers grid-tie equipment with anti-islanding (the inverter has to disconnect from the utility if the utility de-energizes). Pick UL 1741 only if you're building a grid-tied ESS install; pick UL 458 for boats, RVs, and off-grid installs not connected to the utility.

Can the MultiPlus-II 120 V run at 50 Hz?

Yes. The default output is 60 Hz (the US/Canada standard), but 50 Hz is user-selectable via VEConfigure. This matters in a small number of cases — for example, parts of Japan that run 50 Hz / 120 V power, or specific industrial loads that need 50 Hz. For US, Canadian, and Mexican installs, you'll run it at the 60 Hz default and never need to change it.

What warranty does the MultiPlus-II come with?

A 5-year limited warranty from Victron Energy, upgradable to 10 years for an additional 10% of the purchase price. Blue Marine handles the warranty claim process for you. Email support@bluemarine.com to start a claim.

Is the MultiPlus-II waterproof?

No. The enclosure is IP22 — protected against drips from above with the unit tilted up to 15°, but not against splashing or immersion. Install in a vented, dry compartment (engine room, electrical locker, mechanical bay). For wet-mount applications, look at the Phoenix Smart IP43 charger family instead.

Why buy your MultiPlus-II from Blue Marine

• Authorized Victron Energy Distributor — we carry the full Victron line and know the products inside out.
• ABYC-certified marine electrical Advisors on the phone — (800) 628-6306 for sizing, troubleshooting, and warranty support.
• 5-year warranty, upgradable to 10 years — we handle the claim process for you.
• Free US shipping over $49 from our Seattle warehouse.
• 60-day hassle-free returns.
• Local pickup available in Seattle, WA.
• Custom quotes and full system design — our Advisors spec the MultiPlus-II, batteries, MPPTs, communications + solar cables, fusing, monitoring, and the AWG sizes for your battery cables as one package. (We ship the comms and solar cables; battery cables are sourced or fabricated locally to length.)
• Dealer and installer program with trade pricing. Apply here.