Victron Mini Split: Can Victron Run a Heat Pump?

A Victron mini split setup is one of the best off-grid and RV heating and cooling options. Most modern mini splits use inverter-driven compressors that ramp up slowly, so there’s no big startup surge. The questions are voltage (120V or 240V), continuous watts and battery energy. Here’s how to size it with Victron’s datasheets.

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.

Step 1: 120V or 240V?

Check the outdoor unit’s nameplate. Small 9,000–12,000 BTU units often come in 120V versions. Larger units are usually 240V.

120V unit: any single 120V MultiPlus-II or Quattro.
240V unit on battery: you need two 120V units in split phase. Victron’s MultiPlus-II 2x120V and Quattro-II 2x120V pass 240V through from shore or grid, but in inverter mode their output is 120V only, per Victron’s manual and product page. They won’t run a 240V mini split on battery.

Step 2: Victron Mini Split Inverter Sizing

Inverter (120V)	Continuous at 25°C	At 40°C	Zero-load / search
MultiPlus-II 48/3000	2,400W	2,200W	11W / 2W
MultiPlus-II 48/5000	4,000W	3,700W	15W / 3W
2 x MultiPlus-II 48/5000 split phase	8,000W	7,400W	30W / 6W

Source: Victron MultiPlus-II 120V datasheet.

A 12,000 BTU mini split often draws 1,000W or less at full output, and much less at part load once the room is at temperature. A 48/3000 handles that with room for other loads.

Example figures. Check the unit’s rated input watts and maximum amps.

Step 3: Battery Math (Estimate)

Say the unit averages 500W over 10 hours a night in heating mode: 5,000Wh. With about 95% inverter efficiency at 48V (the datasheet maximum for the 48/3000), that’s roughly 5,260Wh from the battery. A 48V bank of about 7–10kWh gives margin for one night plus other loads.

Step 4: Solar

A Victron MPPT 250/100 or 450/100 on a 48V bank can supply daytime cooling directly. In summer, cooling demand tends to line up with solar production, which is what makes mini splits work so well off-grid.

Why 48V

At 1,000W, a 48V system draws about 21A from the battery. A 12V system would draw about 87A. Victron’s MultiPlus-II 48/3000 cable table calls for AWG 1 with a 125A fuse for runs up to 5m. The 12/3000 needs 2x AWG 1/0 with a 400A fuse.

Tips

Turn off search mode if the mini split’s standby draw is low. The inverter may switch off between compressor cycles and the unit may not restart cleanly.
Set the input current limit so the inverter blends shore or generator power with the battery using PowerAssist.

Full specifications for the MultiPlus-II are on Victron’s product page.

Example: A 120V Mini Split in a Tiny House

A 12,000 BTU 120V mini split on a 48V system with a MultiPlus-II 48/3000 and 2kW of solar.

Season	Average draw (estimate)	Hours	Energy
Summer cooling (daytime)	600W	8	About 4.8kWh, mostly from solar
Winter heating (night)	700W	10	About 7kWh, mostly from battery

Estimates; real draw depends on insulation, temperature and the unit’s efficiency. Summer is easy because cooling demand lines up with solar. Winter nights are the harder case, so size the battery for heating.

Example: A 240V Mini Split in an Off-Grid Cabin

An 18,000 BTU 240V unit needs 240V on battery, so the cabin uses two MultiPlus-II 48/5000 units in split phase. At about 1,500W at full output (example value), the pair has plenty of headroom for other loads on both legs.

Heating Efficiency

A heat pump moves heat rather than making it, so it can deliver more heat energy than the electricity it uses. Most mini split makers publish a heating efficiency figure (HSPF or COP). That’s why a mini split can be a practical way to heat a well-insulated space from a battery bank, compared with resistive electric heat. In very cold weather, efficiency and output drop, so check the maker’s low-temperature ratings.

Battery Sizing for Winter Nights

Average heating draw	Hours	Usable energy needed (estimate)	48V lithium bank
400W	10	About 4.2kWh	About 80–100Ah
700W	10	About 7.4kWh	About 150Ah
1,000W	12	About 12.6kWh	About 250Ah

Estimates including about 5% inverter losses, before other loads.

Generator Support in Winter

Short winter days mean less solar. A MultiPlus-II with a generator on AC-in can run the mini split and charge the battery at the same time, and PowerAssist adds battery power if the combined load exceeds the generator’s limit. A Cerbo GX can start the generator automatically when the battery gets low.

Monitoring the Mini Split’s Draw

A SmartShunt on the battery and the Cerbo GX overview show how much the mini split actually uses. After a few days, you’ll know the real average and can fine-tune the battery and solar size.

Wiring the Mini Split to the Inverter

Feed the mini split from a dedicated breaker on the MultiPlus-II’s AC-out-1 subpanel, sized to the unit’s maximum circuit amps on the nameplate. AC-out-1 stays live on battery, while AC-out-2 is live only with shore or generator power, so the mini split belongs on AC-out-1 if you want it running during an outage.

FAQ

Do I need a soft starter?

Usually not for inverter-driven mini splits. Fixed-speed units may need one.

Can a 12V system run a mini split?

Yes, for a small 120V unit, but the battery current is high. 24V or 48V is better.

Can the Quattro run a 240V unit?

Yes, as two 120V Quattros configured for split phase.

Should I use a 24V system for a mini split?

24V works for smaller units and halves the current of 12V. For larger units or whole-cabin systems, 48V keeps cables and fuses smaller still.

Does a mini split run well on a pure sine wave inverter?

Yes. Victron’s MultiPlus-II and Quattro produce pure sine wave output, which suits the mini split’s inverter-driven electronics.

Sources: Victron MultiPlus-II 120V datasheet and manual; MultiPlus-II 2x120V manual; Quattro-II 2x120V product page (victronenergy.com, accessed Oct 2026).