Victron Quattro: Two AC Inputs Explained

This Victron Quattro review covers the 120V Quattro inverter-charger, the bigger sibling of the MultiPlus. Its main difference is two AC inputs with an integrated transfer switch. Connect shore power and a generator, or grid and a generator, and the Quattro switches to whichever source is live. It also inverts, charges and supports parallel, split-phase and three-phase systems.

Electrical work can be dangerous: follow the manual, fuse and size every cable correctly, and use a licensed electrician for anything connected to household wiring.

Go With The Float reviews the Quattro on their sailboat.

Victron Quattro Review: 120V Specs

Spec	48/3000/35-50/50	12/5000/220-100/100	48/10000/140-100/100
AC inputs	2 x 50A	2 x 100A	2 x 100A
Continuous output at 25°C	2,400W	4,000W	8,000W
Continuous output at 40°C	2,200W	3,700W	6,500W
Peak power	6,000W	10,000W	20,000W
Max charge current	35A	220A	140A
Max efficiency	94%	94%	96%
Zero-load power (search mode)	25W (12W)	30W (10W)	60W (15W)
Weight	19kg	34kg	58kg
Zero-load / AES / search	25 / 20 / 12W	30 / 20 / 10W	60 / 40 / 15W

Source: Victron Quattro 3-10kVA 120V datasheet. 24V 5kVA models are also listed.

What We Like

Two inputs, no external switch. Shore and generator connect directly, and the Quattro picks the active source. Each input has its own current limit.
PowerAssist. When the shore or generator supply can’t cover a peak load, the battery adds the difference, then recharges when the load drops.
Uninterrupted main output. It takes over in under 20ms, so computers keep running.
Second output that is live only when AC is present, for loads like a water heater that shouldn’t drain the battery.
Scalable. Two units for split phase, three for three-phase, and up to four sets of three in parallel.
Starter battery charging at 4A on the 12V and 24V models.
Three programmable relays.

What to Watch

Weight and size. The 12V 5kVA unit weighs 34kg, so plan the mounting and the floor or bulkhead.
Idle draw. 30W at zero load on the 12V 5kVA unit (10W in search mode) adds up when off-grid.
120V output per unit. For 120/240V, pair two units for split phase.
Configuration. Advanced setups use VE.Bus software tools or a GX device.

Quattro vs MultiPlus-II

Pick the Quattro if you have two AC sources, need input current up to 100A, or want the largest units for a big boat or off-grid home. Pick the MultiPlus-II if you have one AC source; it’s lighter and simpler.

Settings to Check

Input current limit for each input. Set AC-in-1 and AC-in-2 to match the breaker or generator on each. This is the most common thing people forget.
Battery type and charge voltages. Set them for your battery, especially for lithium.
PowerAssist. Lets the battery top up a weak shore or generator supply during peaks.
Relays. The Quattro has three programmable relays, for example for generator start.

Setup and Troubleshooting Tips

Generator trips or surges. Lower that input’s current limit and let PowerAssist cover peaks.
Wrong input selected. The Quattro prioritises one input when both are live. Wire grid or shore power to the input set as the priority source.
Hot location. Output falls from 4,000W at 25°C to 3,700W at 40°C on the 12V 5kVA.
Can’t change settings by phone. Advanced settings need VEConfigure through an MK3-USB, or a GX device.
No 240V from one unit. Each Quattro gives 120V. Use two units configured for split phase.

Battery Current by Model

Divide the continuous output by efficiency and battery voltage to estimate DC current, which drives cable and fuse size.

Model	Continuous at 25°C	Approx. battery current
48/3000/35-50/50	2,400W	about 53A (94%, 48V)
12/5000/220-100/100	4,000W	about 355A (94%, 12V)
48/10000/140-100/100	8,000W	about 174A (96%, 48V)

The 12V 5kVA model needs very heavy cabling; at that power level many builders move to 24V or 48V for this reason.

Worked Example: Shore Plus Generator

The two AC inputs let shore power and a generator stay connected at once, with the Quattro selecting between them. On a 48/10000, the 140A charger at about 57.6V puts roughly 8kW into the battery. Add the AC loads passing through and set the input current limit to the generator’s rating so it isn’t overloaded; PowerAssist then tops up from the battery when demand spikes.

Standby draw matters off-grid: 60W of zero-load power is about 1.44kWh a day on the 10kVA model, while search mode at 15W cuts that to about 360Wh.

Worked examples are arithmetic estimates from the published ratings above, not test results. Real numbers depend on temperature, cable runs, battery state and load.

In short: the 48/3000 suits smaller homes and cabins with two AC sources, the 12/5000 suits 12V boats and RVs with large DC systems, and the 48/10000 suits whole-home backup where both shore or grid and a generator feed one system.

Want the source figures? The Quattro page on Victron’s site has the datasheet.

Quick Setup Checklist

Wire grid or shore power to the input you will set as the priority source, and the generator to the other.
Set the current limit for AC-in-1 and AC-in-2 to match each breaker or generator.
Choose the battery type and charge voltages for your bank.
Enable PowerAssist so the battery helps during peak loads.
Assign the three programmable relays, for example to start a generator automatically.
Connect a GX device for remote monitoring through VRM.

FAQ

Can the Quattro use shore and generator at the same time?

It connects to one active source at a time and switches between them automatically.

Does it work with lithium batteries?

Yes. Victron lists it as lithium-ion battery compatible, and charge voltages are adjustable.

How fast does it transfer to battery?

Victron lists under 20ms on the main output, enough for computers to keep running.

Can I parallel Quattros?

Yes. Victron supports parallel, split-phase and three-phase setups.

What does the second AC output do?

It is live only when AC input is present, so loads like a water heater run on shore or generator power and leave the battery for essentials.

How much power can the 12/5000 charger put back?

At 220A and about 14.4V, roughly 3.2kW (estimate), which refills a large 12V bank quickly when shore or generator power is available.

Sources: Victron Quattro 3-10kVA 120V datasheet and product page (victronenergy.com); Go With The Float, “Victron Quattro Review: The Ultimate Dual AC Input Marine Inverter/Charger”.

Sources: Victron Quattro 3–10kVA 120V datasheet and product page (victronenergy.com, accessed Oct 2026).