Victron MultiPlus-II 24V Inverter Charger 3kVA and 5kVA
70A OR 120A CHARGER
Serious charge current back into a 24V bank from shore power or a generator, not a trickle.
SWITCHES OVER IN UNDER 20ms
Fast enough that computers and sensitive gear ride through a mains failure. It is a UPS as well.
2400W OR 4000W CONTINUOUS
With 5500W and 9000W peaks for motors and compressors starting up.
POWERASSIST BOOSTS A SMALL SUPPLY
Covers the shortfall from the battery when a generator or shore supply cannot meet a peak.
5 YEAR VICTRON WARRANTY
Backed by a 5 year limited warranty, with free remote monitoring through the VRM portal.
The MultiPlus-II is a combined pure sine inverter and battery charger with two AC outputs, built for professional marine, vehicle and off-grid work as well as grid-connected energy storage. The 24V models suit larger fixed installations and bigger vehicle builds, where running at 24V halves the current for the same output and keeps cable sizes sensible.
The 3kVA model is the 24/3000/70-32. It delivers 3000VA, which is 2400W continuous at 25°C, with a 5500W peak for motor startup and short surges, and carries a 70A charger. The 5kVA model is the 24/5000/120-50, delivering 5000VA or 4000W continuous with a 9000W peak and a 120A charger.
Worth knowing before you size a system: continuous output derates with heat. The 3kVA drops to 2200W at 40°C and 1700W at 65°C, and the 5kVA to 3700W and 3000W. In a hot cabinet or enclosed space, design around the 40°C figure rather than the headline one.
Two features do most of the work in practice. PowerAssist lets the unit fill the gap when a generator or shore supply cannot meet a peak, drawing the shortfall from the battery and then recharging it once the load drops, so a small supply can run bigger loads than it otherwise could. PowerControl works the other way, capping the current drawn from that supply so you never trip the source.
The transfer switch changes over in under 20 milliseconds, fast enough that computers and sensitive electronics do not notice, so it doubles as a UPS. There are two AC outputs: the main one is uninterrupted, while the second is live only when AC input is present, which is where a water heater or anything else that must not flatten the battery should go.
Systems scale by paralleling up to six units or configuring three for three phase. Setup is through VEConfigure, and adding a Cerbo GX or similar brings remote monitoring and configuration through the free VRM portal. It works with lead acid and lithium alike, with an adaptive charge algorithm that adjusts to suit.
