Victron MultiPlus-II — inverter/charger: specifications, models, selection

What it is for

Three devices in one housing

The inverter converts DC from the battery into 230 V pure sine wave AC — as “clean” as from a socket, so you can power electronics, a fridge, a coffee machine or tools with it.

The charger charges the battery as soon as external power is available: campsite hook-up, shore power, generator or mains at home. The standard algorithm is a four-stage adaptive charge with BatterySafe, recommended for lead-acid batteries; for other types, including lithium-ion, charge parameters must be configured according to the battery documentation.

The transfer switch automatically switches loads from mains to battery and back again. It does this in less than 20 ms, so computers and controllers do not notice the power failure — MultiPlus-II works like a UPS.

Campervans and vans — the 12 V 3 kVA model is enough for a kettle or coffee machine.
Yachts — shore power with PowerAssist when the shore connection is weak.
Home energy storage (ESS) — most often 48 V versions; ESS also works at 24 V, with only the 12/3000/120-32 model as an exception.
Off-grid installations — with a generator as a backup source.
Special vehicles — quiet operation of appliances without starting the engine.

MultiPlus-II 48 V 3 kVA — right side view — **The device discussed alongside.** On the front there is only the LED panel and switch — everything else is set up from a computer or through the GX device.

Features

What MultiPlus-II can do

UPS function

After a mains failure or disconnection of the hook-up, it takes over the loads in less than 20 ms. Computers and electronics keep running without interruption.

PowerControl

You set the maximum current drawn from the mains or generator. When loads approach the limit, MultiPlus-II automatically reduces the battery charge current.

PowerAssist

When the shore power is not enough — for example weak campsite hook-up — it adds the missing power from the battery. When the load drops, it uses the surplus for charging.

Two AC outputs

AC-out-1 always works. AC-out-2 is active only when external power is available — connect loads here that should not discharge the battery, for example a water heater. When AC-in power returns, it switches the load on after about 2 minutes.

ESS — energy storage system

Together with a GX device, it works as a home battery storage system: it increases self-consumption from solar PV and powers selected circuits during a grid failure. It has built-in anti-islanding protection.

Expansion

You can connect up to 6 identical units in parallel and build 3-phase systems from three identical models. In grid-connected installations, you cannot connect units in a system above 30 kW at one connection point. The 8, 10 and 15 kVA models can be connected in parallel only with an external AC switch.

Adaptive charger

Bulk – absorption – float – storage with BatterySafe mode: after shallow discharge, absorption is shorter; after deep discharge, longer (up to 8 hours). In storage mode the voltage drops to 2.2 V per cell, and once a week it returns to absorption level.

Relay, Vsense and temperature sensor

Programmable relay (alarm by default, can be set, for example, for generator start), two 0.75 mm² Vsense wires measuring voltage directly at the battery (compensation up to 1 V) and a temperature sensor — included except with 48 V models.

External current transformer

In parallel operation with the grid, the internal current transformer will not measure grid current — an external sensor is needed. It also extends PowerControl and PowerAssist to 50 A (3 kVA) and 100 A (5 kVA).

Models and specifications

Thirteen 230 V models

Model	Battery	Continuous power at 25 °C	Peak power	Charge current	AC switch	Weight
3 kVA
12/3000/120-32	12 V	3000 VA · 2400 W	5500 W	120 A	32 A	19 kg
24/3000/70-32	24 V	3000 VA · 2400 W	5500 W	70 A	32 A	19 kg
48/3000/35-32	48 V	3000 VA · 2400 W	5500 W	35 A	32 A	19 kg
5 kVA
12/5000/220-50	12 V	5000 VA · 4000 W	9000 W	220 A	50 A	33 kg
24/5000/120-50	24 V	5000 VA · 4000 W	9000 W	120 A	50 A	30 kg
48/5000/70-50	48 V	5000 VA · 4000 W	9000 W	70 A	50 A	30 kg
8–15 kVA (48 V only)
48/8000/110-100	48 V	8000 VA · 6400 W	15 000 W	110 A	100 A	42 kg
48/10000/140-100	48 V	10,000 VA · 8000 W	18 000 W	140 A	100 A	49 kg
48/15000/200-100	48 V	15,000 VA · 12,000 W	27 000 W	200 A	100 A	80 kg
New series: 4k, 4k5, 6k5 and 10k (separate datasheet)
12/4k/160-32	12 V	3400 W	6000 W (2 s)	160 A	32 A	22 kg
48/4k5/55-32	48 V	4000 W	7000 W (1 min)	55 A	32 A	22 kg
48/6k5/100-50	48 V	6000 W	11,000 W (1 min)	100 A	50 A	29 kg
48/10k/150-100	48 V	10 000 W	15,000 W (2 min)	150 A	100 A	48 kg

MultiPlus-II 12 V 3 kVA — front with LED panel — **12/3000/120-32.** 12 V version for a campervan: 2400 W continuous output and charging up to 120 A, but at 2 kW almost 200 A flows from the battery.

MultiPlus-II 48 V 3 kVA at an angle — connection compartment cover removed — **48/3000/35-32.** The same enclosure as the 12 and 24 V versions (19 kg), but at 48 V the DC currents are four times lower than at 12 V.

MultiPlus-II 48 V 15 kVA — front of the largest model — **48/15000/200-100.** Largest model: 12 kW continuous, 27 kW peak, 200 A charging and 80 kg weight — parallel connection only with an external AC switch.

How to read the name: 24/3000/70-32 = 24 V battery / 3000 VA output / 70 A charge current / 32 A AC switch. Continuous power drops with ambient temperature — for example, the 3 kVA model delivers 2400 W at 25 °C, 2200 W at 40 °C and 1700 W at 65 °C. In the new series, the datasheet gives continuous power in kW and peak power together with its duration. There are also 120 V versions for the American market.

Output voltage: 230 V ±2%, 50 Hz (60 Hz possible)
Charger AC input: 187–265 V, 45–65 Hz
DC voltage range: 9.5–17 / 19–33 / 38–66 V
Absorption / float (default): 14.4 / 13.8 V (for 12 V)
Maximum efficiency: 93–96%
Search mode consumption: 2–6 W (new series 4–8 W)
Operating temperature: −40 … +65 °C
Enclosure: steel, IP22 (new series IP21)
Programmable relay: yes (alarm, generator start)
Battery temperature sensor: included, except with 48 V models

New series

MultiPlus-II 4k5 and 6k5 — more power per kilogram

The manufacturer describes the new models with the phrase “more power per kilogram and per litre, better performance at high temperature”. The 48/4k5/55-32 model weighs 22 kg (590 × 275 × 149 mm), and the 48/6k5/100-50 model weighs 29 kg (644 × 320 × 150 mm). For comparison, the 48/5000/70-50 from the older series weighs 30 kg.

In the 4k5 and 6k5 models, the number in the name refers to short-term power at cold start, not continuous power: 4k5 provides 4.5 kW for 2 hours, 6k5 — 6.5 kW for 4 hours. Continuous output at 25 °C is 4 kW and 6 kW respectively.

Short-term power 2: 4k5 — 6 kW for 25 min, 6k5 — 8 kW for 1 h; peak 7 kW and 11 kW for 1 min.
Charging 55 A and 100 A at 25 °C, 50 A and 95 A at 40 °C; absorption 57.6 V, float 55.2 V.
AC input 32 A (4k5) and 50 A (6k5) — this is also the factory limit for PowerControl and PowerAssist. In a parallel system with the grid, with an external 100 A current transformer, the range increases to 50 A (4k5) and 100 A (6k5).
Enclosure steel IP21, operating from −40 to +65 °C, up to 4000 m above sea level with a 1% power reduction for every 100 m above 2000 m.
Battery temperature sensor is optional in 48 V models (ASS000001000); included in 12/4k.

MultiPlus-II 48/6k5/100-50, left side — flat wall housing — **Flat wall-mount enclosure.** The 6k5 is only 150 mm deep and 644 mm high. Wall mounting on a solid surface — there is a hook and two holes on the rear of the enclosure.

MultiPlus-II 48/4k5/55-32 — front — **48/4k5/55-32.** 4 kW continuous, 55 A charging, 32 A AC input and switch, 22 kg. Maximum efficiency 95%, no-load consumption 20 W.

MultiPlus-II 48/6k5/100-50 — front — **48/6k5/100-50.** 6 kW continuous, 100 A charging, 50 A AC input and switch, 29 kg. Maximum efficiency 96%, no-load consumption 28 W.

MultiPlus-II 48/4k5 — connection compartment after removing the service panel — **4k5 connections.** The service panel is held in place by two screws at the bottom. The battery is connected with M8 bolts (12 Nm), the AC terminals are screw terminals for up to 13 mm² (2 Nm).

New series	DC fuse	Cable 0–5 m	Cable 5–10 m	Battery capacity	AC-out-2
12/4k/160-32	600 A	2 × 70 mm²	2 × 95 mm²	400–1200 Ah	32 A
48/4k5/55-32	180 A	50 mm²	70 mm²	200–800 Ah	32 A
48/6k5/100-50	250 A	70 mm²	95 mm²	250–1200 Ah	32 A
48/10k/150-100	400 A	2 × 50 mm²	2 × 70 mm²	250–1200 Ah	50 A

Cross-section per pole, “2×” means two positive and two negative cables. Copper cables with 90 °C insulation, not in a closed conduit. Data from the “MultiPlus-II 4k, 4k5, 6k5, 10k 230V” manual; electrical data from the datasheet for this series. The datasheet and the manual differ in a few places: 12/4k — peak power 6 kW for 2 s (datasheet) or 30 s (manual) and short-term power 4.5 kW for 30 min (datasheet) or 2 s (manual); 10k — efficiency 95% (datasheet) or 93% and AC input 187–265 V (datasheet) or 187–250 V (manual). In the tables we give the datasheet values.

Typical setup

Where the MultiPlus-II sits in the system

Simplified layout of a campervan, yacht or cabin. Hover over or tap a diagram element to see the description.

direct current (DC) 230 V (AC) communication

Hover over or tap a diagram element.

Mains / generator → AC-inExternal power supply. You set the input current limit in the MultiPlus-II.
MultiPlus-IITransfers mains power to the loads and charges the battery, or produces 230 V from the battery.
AC-out-1 → 230 V loadsAlways active — from the mains or from the battery.
AC-out-2 → water heaterOnly when external power is available, so as not to discharge the battery.
Battery + MPPTShared energy storage charged from the mains and from panels.
Cerbo GX (VE.Bus)Monitoring, control and remote access via VRM.

Connections

What is under the service cover

MultiPlus-II 48 V 3 kVA — connection compartment: AC-OUT-1, AC-OUT-2 and AC-IN terminals, battery terminals and auxiliary contacts — **3 kVA model.** From the left: AC-OUT-1, AC-OUT-2 and AC-IN terminals, next to them the auxiliary contacts and remote on/off, battery terminals on the right.

MultiPlus-II 24 V 5 kVA — entire connection compartment with the cover removed — **5 kVA model.** The layout is the same, only the battery terminals and cable glands are larger — at 24 V the charge current reaches 120 A.

MultiPlus-II 48 V 15 kVA — battery terminals and three large cable glands — **15 kVA model.** Here the battery cables already have cross-sections measured in hundreds of square millimetres, and there are three cable glands.

AC terminal strips — terminal order from the left: N (neutral), PE (protective earth), L (line). Do not swap N and L. Torque on the AC-out-2 terminals: max. 2 Nm.
AC input protection — circuit breaker no greater than 32 A (3 kVA models), 50 A (5 kVA) or 100 A (8, 10 and 15 kVA); in the new series the maximum input current is 32 A (4k, 4k5), 50 A (6k5) and 100 A (10k). If the source has a lower rating, choose a smaller one.
AC-out-1 output — PowerAssist adds up to 3 kVA, i.e. 13 A, so with a 32 A input you can draw up to 45 A from the output. Overcurrent protection and RCD are selected for this value.
Battery terminals — M8 bolts, 12 Nm torque, torque wrench with insulated socket. AC screws: M4 — 1 Nm, M5 — 3 Nm, M6 — 5.5 Nm; in the new 4k–6k5 series, 13 mm² screw terminals, 2 Nm torque.
Vsense — two 0.75 mm² wires measure the voltage directly at the battery; the charger will compensate for a voltage drop of up to 1 V per terminal, and with a larger drop it will reduce the charging current.
Remote control — a simple switch on the “remote on/off” terminals or a Digital Multi Control panel in the RJ45 socket; it works only when the switch on the unit is in the “on” position.

MultiPlus-II 48 V 10 kVA — connection compartment with heavy battery terminals and cable glands — **The larger the model, the thicker the cables.** In 8–15 kVA models, the battery terminals are designed for currents of around 200 A.

Which one should you choose?

Choosing the model in practice

Campervan, van

12 V · 3 kVA or 4k

Kettle, coffee machine or microwave (2.4 kW continuously, and in the new 12/4k — 3.4 kW). At 2 kW, around 170–190 A flows from a 12 V battery — the cables and battery must be able to handle it.

12/3000/120-32 · 12/4k/160-32

Yacht, large campervan

24 V · 3 or 5 kVA

Higher voltage means half the current compared with 12 V: thinner cables and lower losses. The 5 kVA model is suitable for air conditioning or induction cooking.

24/3000/70-32 · 24/5000/120-50

Home, ESS, off-grid

48 V · 4k5–15 kVA

Standard in energy storage systems. The lighter 4k5 and 6k5 models in the new series provide 4 and 6 kW of continuous power. For higher power, units are connected in parallel or in a three-phase system.

48/4k5/55-32 · 48/6k5/100-50 · 48/10000/140-100

When another device will be better

	MultiPlus-II	Quattro-II	MultiPlus-II GX	Phoenix Inverter Smart
230 V inverter	yes	yes	yes	yes
Mains / generator charger	yes	yes	yes	no
AC inputs	1	2 (mains + generator)	1	—
UPS function	yes	yes	yes	no
Built-in GX centre	no	no	yes	no
When to choose	most systems	two AC sources without a changeover switch	fewer devices and cables	only 230 V from the battery

Installation and configuration

What to watch out for

230 V installation is work for an electrician

Residual current protection, earthing and connection to the home mains should be carried out by a qualified person. Before working on the MultiPlus-II, disconnect the AC supply and the battery; dangerous voltage may still be present at the terminals even after the unit has been switched off. The MultiPlus-II has an internal earthing relay which connects N to PE in inverter mode — this must be taken into account when selecting protection devices.

DC side: short, thick, with a fuse

There must be a fuse and disconnect switch between the battery and the MultiPlus-II. Take the cable cross-sections and fuse ratings from the manual for the specific model — at 12 V, currents reach several hundred amperes.

Configuration

Settings are changed via the MK3-USB interface and the VictronConnect app or VEConfigure software. Via Bluetooth: the VE.Bus Smart dongle (Bluetooth) lets you monitor the unit, switch it on and off, and change the AC input current limit — to change settings you need the MK3-USB interface. Remotely — via the GX centre and the VRM portal.

Set the battery before the first charge

Set the absorption and float voltages according to the battery type. Lithium batteries require a BMS compatible with the system. For Victron Lithium Smart, use VE.Bus BMS V2 or Lynx Smart BMS. Install and configure other lithium batteries in accordance with the list of compatible Victron battery types and the installation and configuration manual.

IP22 (new IP21 series) — dry location only

The enclosure is not waterproof. Install in a dry, well-ventilated place, with clear space for fan cooling.

MultiPlus-II 48 V 4.5 kVA — open service cover — **This is where the cables enter.** MultiPlus-II 48 V 4.5 kVA — service cover open

Location: dry and well ventilated, as close to the battery as possible, but never directly above it. The mounting surface must support the unit’s mass (19–80 kg) — there is a hook and two holes on the rear of the enclosure, and larger models have a separate mounting plate. The interior must remain accessible after installation.
DC cables: copper, 90 °C insulation, short and thick — the manual gives, for each model, battery capacity, fuse and cross-section (e.g. 24/3000/70: 200–700 Ah, 300 A, 50 mm²; 48/5000/70: 200–800 Ah, 200 A, 70 mm²; 12/5000/220: 600–2400 Ah, 600 A, 2 × 95 mm²). For runs of 5–10 m, cross-sections increase.
Parallel operation: up to six identical units on a common battery, identical lengths and cross-sections of the DC cables, at least 10 cm of free space around each unit, UTP cables straight from unit to unit (no splitters), battery negative cables connected before the UTP and only one remote panel. 8, 10 and 15 kVA models may be connected in parallel only with an external AC switch.
Three-phase: three identical units in a star (Y) configuration — delta is not supported. Up to six such sets can be connected (45 kW), but this does not apply to the 8, 10 and 15 kVA models. In a grid-connected installation, you must not exceed 30 kW at a single connection point.
Generator in one enclosure (hybrid generator) requires vibration mounts matched to the unit’s mass and the generator’s vibration frequency.

MultiPlus-II mounting plate for wall mounting the unit — **Mounting plate.** The unit is hung on the wall using the hook and two holes on the back of the enclosure; the mounting surface must be strong and non-combustible.

Settings

What the unit comes with from the factory

The factory settings are intended for operation of a single unit with a Victron gel battery. With a different battery type — especially lithium — the voltages and charging current must be changed before the first charge.

Output voltage and frequency	230 V, 50 Hz
AC input range	180–270 V, 45–65 Hz
Operation	standalone (not parallel or three-phase)
Battery type	Victron Gel Deep Discharge (AGM Deep Discharge also fits)
Charge curve	four-stage adaptive with BatterySafe, 100% of maximum current
Absorption / float / storage	14.4 / 13.8 / 13.2 V — respectively ×2 at 24 V and ×4 at 48 V (storage not adjustable)
Absorption time	up to 8 hours, depending on the bulk phase; repeat 1 h every 7 days
AC input current limit	32 A (3 kVA), 50 A (8 and 10 kVA) — this is also the PowerControl and PowerAssist threshold
Functions enabled	PowerAssist, UPS, bulk phase protection, earthing relay, programmable relay as alarm
Functions disabled	AES (economy mode), automatic equalisation, dynamic current limiter, WeakAC

The minimum input current limit with PowerAssist enabled is 4 A for 3 kVA models, 6 A for 5 kVA and 11 A for 8–15 kVA. Settings are changed via MK3-USB (VictronConnect or VEConfigure), and in a complete system — via the GX centre and the VRM portal.

Diagnostics

Symptom and what to do about it

The MultiPlus-II has no display — status is shown by the LED panel on the front, and in a system with a GX centre the same information is visible on the screen and in the VRM portal. Below are the symptoms from the manual; we have collected the full description of the signals in the LED decoder.

“low battery” LED flashes

The battery voltage is low. Charge the battery or check the DC connections. When the LED lights continuously, the inverter has already shut down.

“overload” LED flashes

The load exceeds the rated power — reduce it. A continuously lit LED means the inverter has shut down due to overload.

“temperature” lights or flashes

The ambient temperature is too high or the load is too heavy. Move the unit to a cooler, better-ventilated place or reduce the load.

“low battery” and “overload” LEDs flash alternately

Battery voltage is low and the load is too high at the same time. Charge the battery, disconnect some loads, or increase the battery bank; shorter, thicker cables will also help.

Both LEDs flash at the same time

Ripple at the DC terminals exceeds 1.5 Vrms. Check the battery cables and connections, and whether the battery bank capacity is sufficient.

Both LEDs are continuously lit

The inverter has shut down due to excessive ripple. Use a battery with a larger capacity, shorter and thicker cables, then restart the unit with the switch.

No voltage on AC-out-2

The unit is operating from the battery. When AC input becomes available, this output returns after a delay of about 2 minutes.

Does not switch to mains or generator

The AC input protection has tripped due to overload. Remove the overload or short circuit on AC-out-1 and AC-out-2, then reset the breaker.

The inverter does not start after switching on

Battery voltage is too high or too low, or there is no voltage at the DC terminals. Check the voltage range and connections.

Charger not working

Input voltage outside the 185–265 V range, or frequency outside the set range; the AC input protection has tripped or the battery fuse has blown. With ‘dirty’ generator voltage, enable WeakAC and the dynamic current limiter.

“bulk protection” message

Charging in bulk phase lasted more than 10 hours — this may indicate a damaged cell. Check the battery; the error clears when you switch the unit off and on.

The battery does not fully charge

Most often the absorption or float voltage is too low, the charge time is too short, or the connection at the terminals is poor. Check the settings for your battery type and tighten the terminals.

In a parallel or three-phase system, the units also show VE.Bus codes — you can find the list in the VE.Bus error codes section.

Questions

Frequently asked questions about MultiPlus-II

Will the MultiPlus-II 12/3000 run an electric kettle?

Yes — the model delivers 2,400 W of continuous power at 25 °C and up to 5,500 W peak, so a 2 kW kettle will work. Just remember that at 12 V battery voltage it will draw about 170–190 A, so the battery, cables and fuse must be ready for that.

How does PowerAssist work at a campsite with a 6 A breaker?

You set the input current limit to match the shore power breaker — remember the minimum: 4 A for 3 kVA models, 6 A for 5 kVA, and 11 A for 8–15 kVA. As long as the loads stay within the limit, they are powered by shore power and the surplus charges the battery. When you switch on something larger, the MultiPlus-II adds the missing power from the battery and the pedestal breaker does not trip.

Can I connect solar panels directly to the MultiPlus-II?

No — the MultiPlus-II has no PV input. Panels are connected through an MPPT solar charge controller to the battery (the most common solution in vehicles and off-grid systems) or through a grid-tie inverter on the AC output. In the latter case, the “Factor 1.0” rule described in Victron documentation applies.

How does the MultiPlus-II differ from the older MultiPlus?

It has all the functions of the predecessor, plus the option of an external current sensor (PowerControl and PowerAssist with current transformer: 3 kVA models up to 50 A, 5 kVA up to 100 A), built-in anti-islanding protection and grid-parallel certificates for many countries, which are required in ESS systems.

How many units can I connect together?

Up to 6 identical models in parallel. Three identical models form a three-phase system, and up to six such sets can be connected. The 8, 10 and 15 kVA models can only be paralleled with an external AC switch.

Does the MultiPlus-II have grid-parallel certificates for Poland?

The manufacturer’s website includes PTPiREE certificates and compliance with EU Regulation 2016/631 for Poland. They cover selected models and configurations, so before notifying the installation to the grid operator, check the current certificate for your model.

When does AC-out-2 work?

Only when AC input power is present. After mains failure, the loads on this output are disconnected immediately, and when power returns they come back after a delay of about 2 minutes — the time needed for the generator to stabilise. AC-out-1 always operates.

Is a battery temperature sensor included?

Yes, except on 48 V models — there it is ordered separately. The sensor is mounted on the negative battery terminal and reduces the charge voltage when the battery warms up. The Vsense wires work separately; they measure the voltage directly at the battery and compensate for up to 1 V drop per pole.

What does the ground relay do?

In inverter mode it connects the output neutral conductor to the enclosure, and when external power appears it opens before the input relay closes — this ensures the residual-current device on the output works correctly. The internal mains transformer eliminates the DC component, so a type A RCD is sufficient. By default, the relay is enabled.

Do I need to change any settings after purchase?

With a gel or AGM battery, usually not — those are the factory settings. With any other battery, especially lithium, set the battery type, absorption and float voltages, and charge current before the first charge. You do this via the MK3-USB interface (VictronConnect or VEConfigure) or remotely through the GX device.

When something does not work

Fits

Devices it works with most often

Cerbo GX

Monitoring, control and VRM

SmartSolar MPPT

Charging the battery from panels

SmartShunt

Battery state of charge

Quattro-II

When you have two AC sources

Sources

Manufacturer documentation

We prepared this description independently based on the manufacturer’s documentation. If there are any discrepancies, the current Victron Energy documentation is binding. You can report an error here.