Victron MultiPlus-II 24/3000/70-50 120V Inverter/Charger
Inverter, Battery Charger & Automatic Transfer Switch The Victron MultiPlus-II 24/3000/70-50 120V combines a powerful pure sine wave inverter, a 70A battery charger and a 50A automatic transfer switch in one integrated unit. It is designed for 24V battery systems in RVs, boats, off-grid cabins, tiny homes, service vehicles and backup-power installations. When shore power, utility power or a generator is available, the MultiPlus-II passes that power through to the connected loads while charging the battery. If the AC source is disconnected or rejected, it automatically changes to inverter power in less than 20 milliseconds—fast enough that most computers and electronic equipment continue operating without interruption. What Does 24/3000/70-50 Mean? Rating What It Means 24 Designed for a nominal 24V battery bank 3000 3000VA inverter rating with 2400W continuous real-power output at 25°C 70 Up to 70A of battery charging from an available AC source 50 50A AC input and automatic transfer-switch capacity This Is a 120V Model PMP242305102 has one 120V AC input and supplies 120V AC output. It is not the MultiPlus-II 2×120V model and does not independently supply 120/240V split-phase power from a single unit. Why You'll Love It 3000VA pure sine wave inverter 2400W continuous output at 25°C Up to 5500W of short-duration peak power Powerful 70A adaptive battery charger Built-in 50A automatic transfer switch Less than 20ms transfer to inverter power PowerControl prevents overloading limited AC sources PowerAssist supplements shore or generator power from the battery Second AC output for loads that should only operate with external AC available Programmable relay for alarms or compatible generator start/stop control VE.Bus connectivity for monitoring, configuration and system expansion Compatible with optional Cerbo GX, remote panels and Bluetooth adapter Suitable for properly configured lithium and lead-acid batteries UL 458 listed for mobile and off-grid applications Backed by Victron's 5-year warranty 3000VA Does Not Mean 3000W Continuous The inverter is rated for 3000VA, but its continuous real-power rating is 2400W at 25°C. This distinction is important when comparing inverter sizes or determining whether it can operate a particular appliance. Operating Condition Output Rating Continuous Output at 25°C 2400W / 3000VA Continuous Output at 40°C 2200W Continuous Output at 65°C 1700W Peak Output 5500W The strong peak rating helps start compatible refrigerators, pumps, compressors and other motor loads. Successful starting still depends on the appliance, battery condition, BMS discharge rating, cable size and voltage drop within the DC system. Contact Us for Load Compatibility Help Automatic Transfer Between AC and Battery Power When an acceptable 120V AC source is connected, the MultiPlus-II transfers that power to AC-out-1 and uses available capacity to charge the battery. If the source fails, is disconnected or falls outside the configured voltage and frequency limits, the inverter automatically takes over. Transfer to inverter operation takes less than 20 milliseconds. This makes the MultiPlus-II suitable for applications where refrigerators, communications equipment, computers and other essential loads should continue operating when shore power or generator power is interrupted. Charger-Only Mode The front switch can be placed in charger-only mode when battery charging and AC passthrough are required but automatic inverter operation is not. If the external AC source disappears, the inverter remains off instead of continuing to power loads from the battery. PowerControl & PowerAssist PowerControl allows the maximum AC input current to be adjusted for the connected source. The MultiPlus-II accounts for the power being used by AC loads and reduces battery charging when necessary to avoid overloading a limited shore-power connection or generator. PowerAssist goes one step further. When a temporary load exceeds the available shore or generator capacity, the MultiPlus-II can add inverter power from the battery. Once the load decreases, available AC power can again be used to recharge the battery. Works with Smaller AC Sources The 50A rating is the maximum AC input capacity—not the minimum required source size. The input-current limit can be reduced for a compatible 15A, 20A or 30A connection. The setting must match the available source and the installed AC protection. Two AC Outputs for Better Load Control AC-out-1 is the primary output. It remains powered from the inverter when shore, generator or utility power is unavailable. AC-out-2 is a source-dependent auxiliary output rated for up to 32A. It disconnects immediately when the MultiPlus-II changes to battery operation and reconnects approximately two minutes after acceptable AC input returns. This second output is useful for equipment that should operate only when shore power or a generator is available, such as an electric water heater, large battery charger or other non-essential load that should not discharge the house battery. AC-out-2 Is Not a Second Inverter Circuit AC-out-2 is not powered during battery-only operation. It is specifically intended for loads that should be automatically disabled when the system is running from the battery. 70A Adaptive Battery Charging The built-in charger can supply up to 70A to a compatible 24V battery bank. Charging current and voltage settings can be adjusted to meet the requirements of LiFePO₄, AGM, gel and flooded lead-acid batteries. The four-stage adaptive charging system uses bulk, absorption, float and storage stages. For lead-acid batteries, the adaptive algorithm adjusts absorption time based on the preceding discharge and reduces long-term float voltage when the battery remains unused. Maximum 70A charging current Adjustable charging current and voltage settings BatterySafe and storage modes for lead-acid batteries Battery voltage-sense connection for cable-drop compensation Battery temperature sensing Two programmable input/output ports for compatible BMS integration 4A maintenance-charging output for a separate 24V starter battery Battery Settings Must Be Confirmed The factory charging profile may not be correct for every battery. Charging voltages, maximum current, low-voltage shutdown settings and any required BMS communication must be configured for the installed battery system before regular operation. Get Help Confirming Battery Compatibility Battery Bank Requirements At full continuous inverter output, a 24V battery system may need to supply approximately 110A before allowing for changing battery voltage and other installation losses. Starting surges can require considerably more current for a short period. The battery bank, internal BMS, busbars, disconnects, fuse and cabling must all be capable of supporting the inverter's continuous and surge current. Victron lists a recommended battery-bank range of approximately 200Ah to 700Ah for this model. Suitable for a Properly Rated 24V 200Ah Battery A 24V 200Ah LiFePO₄ battery can be an appropriate match when its BMS discharge rating supports the intended loads and inverter surge current. Available runtime still depends on battery capacity, load size, inverter losses, temperature and the permitted depth of discharge. Monitoring, Bluetooth & System Control The MultiPlus-II uses VE.Bus for communication and system integration. It does not include built-in Bluetooth or a VE.Direct port. Monitoring Option What It Provides VE.Bus Smart Dongle Optional local Bluetooth monitoring, on/off/charger-only control and AC input-current adjustment through VictronConnect MK3-USB Interface Direct computer connection for detailed VE.Bus configuration and firmware work Digital Multi Control Panel-mounted on/off/charger-only control with adjustable AC input-current limit Cerbo GX Central system monitoring, Remote Console, optional internet-connected VRM access and integration with other Victron equipment Bluetooth Is Optional The MultiPlus-II does not connect directly to VictronConnect by Bluetooth. An optional VE.Bus Smart Dongle can add convenient local monitoring and basic control, but it does not replace an MK3-USB or compatible GX device for every advanced configuration task. View Cerbo GX MK2 Ask About Control Accessories Compatible Generator Integration The MultiPlus-II can accept compatible 120V generator power through its AC input. PowerControl can reduce battery charging to stay within the generator's available output, while PowerAssist can supplement short periods of higher demand from the battery. The programmable dry-contact relay can also be configured for generator start and stop control. This is generally suitable for a generator or generator controller that accepts a compatible two-wire start signal. Automatic Generator Start Requires Configuration The relay can be programmed to respond to conditions such as battery voltage, load or battery state. The correct generator interface, control logic and configuration are installation-specific. A Cerbo GX can provide more extensive generator start/stop conditions and monitoring when required. Contact Us for Generator Compatibility Help DC Cabling, Fuse & Installation Planning A high-power inverter/charger requires very low-resistance DC connections. Cable length, conductor size, terminal quality, fuse selection and connection torque directly affect starting performance, charging accuracy and system reliability. Victron Installation Reference Published Guidance Suggested Battery Capacity 200Ah to 700Ah DC Fuse 300A DC Cable Length up to 5m AWG 1/0 positive and AWG 1/0 negative DC Cable Length from 5m to 10m Two AWG 1/0 positive and two AWG 1/0 negative Battery Connections Two M8 studs Battery Terminal Torque 12Nm The values above reproduce Victron's general installation table. Final conductor size, fuse type, disconnects, routing and protection must comply with the complete installation, applicable electrical requirements and the ampacity of the selected cable. Victron specifically states that the battery cables should not be installed in a closed conduit. Shop Circuit Protection Get Help Planning the DC System Professional AC Installation Required The MultiPlus-II contains hazardous AC and high-current DC connections. AC input, output, grounding, neutral switching, branch protection and disconnecting equipment must be designed and installed in accordance with the Victron manual and applicable electrical requirements. What Else Is Required? The MultiPlus-II is the inverter, AC charger and transfer switch. It is not a complete electrical system by itself. Compatible 24V battery bank Properly sized battery cables and terminals Battery-side fuse and disconnect Appropriate positive and negative DC distribution AC input and output wiring Required AC breakers, disconnects and ground-fault protection Solar charge controller if solar charging will be used Solar panels, PV wiring and PV protection as required Optional monitoring or configuration hardware Battery cables, fuse protection, AC wiring, solar equipment, VE.Bus cables and monitoring accessories are sold separately unless specifically stated otherwise. Applications Off-grid cabins and tiny homes RVs, campers and motorhomes Boats and marine house-power systems Service trucks and mobile work trailers Backup power for essential 120V loads Generator-supported battery systems 24V lithium or lead-acid battery banks Systems requiring automatic AC transfer Systems using Cerbo GX and VRM monitoring Expandable parallel or multi-phase VE.Bus systems Product Specifications Specification Value Model MultiPlus-II 24/3000/70-50 120V Victron Part Number PMP242305102 Nominal Battery Voltage 24V DC Input Voltage Range 19V to 33V AC Output Voltage 120VAC ±2% Output Frequency 60Hz ±0.1% Inverter Waveform Pure sine wave Inverter Rating 3000VA Continuous Output at 25°C 2400W Continuous Output at 40°C 2200W Continuous Output at 65°C 1700W Peak Power 5500W Maximum Efficiency 94% Zero-Load Consumption 13W Zero-Load Consumption — AES Mode 9W Zero-Load Consumption — Search Mode 3W AC Input Single-phase 120VAC Accepted AC Input Voltage 90V to 140VAC, configurable within supported limits Accepted AC Input Frequency 55Hz to 65Hz Maximum AC Input Current 50A Transfer Switch 50A Transfer Time Less than 20ms PowerControl Yes PowerAssist Yes Maximum Battery Charging Current 70A Default Absorption Voltage 28.8V Default Float Voltage 27.6V Default Storage Voltage 26.4V Charging Algorithm Four-stage adaptive with BatterySafe mode Starter-Battery Charge Output 4A maintenance output for a 24V starter battery Primary AC Output AC-out-1; inverter-backed Auxiliary AC Output AC-out-2; 32A maximum, available only with external AC input Communication VE.Bus through two RJ45 ports Built-In Bluetooth No; optional VE.Bus Smart Dongle required Remote On/Off Yes Programmable Relay Yes; alarm, low-voltage or compatible generator start/stop functions Programmable Inputs/Outputs Two analogue/digital ports Parallel Operation Up to six identical units with appropriate system configuration Battery Connections Two M8 studs AC Connections Screw terminals accepting up to 13mm² / AWG 6 Protection Rating IP22 Cooling Fan-assisted Operating Temperature -40°C to +60°C; output derates at elevated temperature Dimensions 536 × 277 × 147mm Weight 19kg / 42lb Listing UL 458 Safety Standard CSA C22.2 No. 107.1-16; EN/IEC 60335-1 and EN/IEC 60335-2-29 Warranty 5 Year Specifications are believed to be accurate at the time of publication but may change without notice. While we make every effort to keep product information current, Sapphire Energy cannot guarantee all specifications are complete, error-free or up to date. Please refer to the manufacturer’s documentation if a particular specification is critical to your application. Contact us for help! Frequently Asked Questions Is the continuous output 3000W? No. The inverter is rated at 3000VA, while Victron specifies 2400W of continuous real-power output at 25°C. Continuous output decreases at higher operating temperatures in order to protect the inverter from damage. However, It can provide substantially more power for short starting surges, with a published peak rating of 5500W, meaning you can start motor loads with ease. Can it supply 240V appliances? Not by itself. This model has a single 120V AC input and produces 120V AC output. Split-phase or multi-phase systems can be created with additional compatible Victron equipment and configuration, but that is a system-design project rather than a feature of one standalone unit. Contact Us for System Design Help Can I connect it to a 30A shore-power supply? Yes. The 50A rating is the maximum accepted AC input current. The input-current limit can be reduced to match a compatible 30A or smaller AC source. Once correctly configured, PowerControl reduces charging when necessary to keep the combined charger and AC loads within the selected input limit. What happens when shore or generator power fails? AC-out-1 changes to inverter power in less than 20 milliseconds. Most computers and ordinary electronics can continue operating without a noticeable interruption. AC-out-2 switches off because that output is intentionally powered only while an acceptable external AC source is available. What is the second AC output used for? AC-out-2 is intended for loads that should operate only when shore, utility or generator power is available. It disconnects during battery operation so those loads cannot discharge the house battery. Common examples include an electric water heater or another large non-essential load. AC-out-2 is rated for a maximum of 32A and requires appropriate external protection. Can it charge lithium batteries? Yes. It can charge compatible 24V LiFePO₄ batteries when the charging voltages, maximum current, low-voltage settings and any required BMS controls are correctly configured. The battery and BMS must also support the inverter's continuous and surge discharge requirements. Get Help Confirming Battery Compatibility Does it include a solar charge controller? No. The built-in 70A charger operates from an AC source such as shore power, utility power or a generator. Solar panels require a separate appropriately sized solar charge controller connected to the 24V battery system. Does it have built-in Bluetooth? No. The MultiPlus-II communicates through VE.Bus and does not have built-in Bluetooth. The optional VE.Bus Smart Dongle adds Bluetooth monitoring and basic control through VictronConnect. A Cerbo GX can provide more complete system monitoring, Remote Console and optional VRM internet access. View Cerbo GX MK2 Ask About Bluetooth Options Can it automatically start a generator? Yes, when used with a compatible generator or generator controller that accepts an appropriate two-wire start signal. The MultiPlus-II has a programmable dry-contact relay that can be configured for generator start and stop control. The relay logic and generator interface must be configured for the specific installation. A Cerbo GX can provide additional generator-control conditions, monitoring and scheduling options. Contact Us for Generator Compatibility Help What size battery bank should I use? Victron's general recommendation for this model is approximately 200Ah to 700Ah at 24V. The correct capacity depends on the required runtime, expected loads, battery chemistry, charging sources and permitted depth of discharge. Capacity alone is not enough—the battery BMS must also support the inverter's continuous and peak current requirements. What battery fuse and cable does Victron specify? Victron's installation table lists a max 300A DC fuse and AWG 1/0 positive and negative battery cables for cable lengths up to 5m. For lengths between 5m and 10m, it lists two parallel AWG 1/0 conductors for each polarity. These are manufacturer reference values, not a substitute for installation-specific electrical design. Final cable and fuse selection must account for conductor ampacity, routing, temperature, cable type, local requirements and all connected equipment. Shop Circuit Protection Get Help Planning the DC System Can multiple units be connected together? Yes. Up to six identical units can be configured in parallel for additional capacity. Compatible units can also be used in professionally designed split-phase or three-phase VE.Bus systems. Multi-unit systems require identical equipment, matching DC cabling, VE.Bus communication cables and specialized configuration. Can it be connected to utility power? Yes—for incoming power and battery backup, but not as a grid-tied solar inverter. The MultiPlus-II can receive 120V utility power through its AC input, pass that power through to connected loads and use it to charge the battery. If utility power fails, it can automatically switch AC-out-1 to battery-powered inverter operation. The PMP242305102 is UL 458 listed for mobile, marine, off-grid and backup-power applications. Although the MultiPlus-II platform supports bidirectional operation, this model's grid-feed functionality is not UL 1741 or CSA grid-interconnection certified. It should therefore not be used to export battery or solar power back into the utility grid as a standalone grid-tie inverter. Any system intended to operate in parallel with—or export power to—a utility grid must use the required certified equipment and be designed in accordance with local electrical codes, utility requirements and approval from the applicable authority. What warranty does this product include? This inverter/charger is backed by Victron Energy's 5-year limited warranty. If you need troubleshooting or warranty assistance, Sapphire Energy will work with you throughout the process. Contact Us Planning a Complete Victron System? Contact us with your battery specifications, largest AC loads, shore or generator capacity, solar array and required runtime. We can help confirm inverter sizing, battery compatibility, charging capacity, monitoring equipment and the additional wiring and protection required for the installation. Contact Us for System Planning Help