Tool

Inverter selection

List the 230 V loads that may run at the same time. We will calculate the continuous power and instantaneous surge, suggest the system voltage and the smallest Victron model that can handle them — even in the heat.

23Victron models with datasheet data

40 °Ccontinuous power in heat, e.g. in a campervan cupboard

12 Vup to 3000 VA according to “Wiring Unlimited”

24 Vup to 5000 VA, above 48 V

1Loads running at the same timenameplate power; start-up only for devices with a motor or compressor

Quick add:

The powers in “quick add” are typical values — if you know the power from your nameplate, correct it.

2Device typewhere current should come from apart from the battery

Inverter/chargermains, campsite hook-up or generator · MultiPlus-II, Multi RS, Quattro Inverter onlybattery only · Phoenix, Inverter RS Two AC inputsmains and generator at the same time · Quattro

3Installationbank voltage and conditions with the inverter

Battery voltage

Select 12 V 24 V 48 V

Temperature at the inverter

up to 40 °C up to 25 °C

40 °C — cupboard, campervan in summer; 25 °C — cool room

How we calculate

Assumptions

Phoenix VE.Direct250–1600 VA · inverter only

Phoenix Inverter Smart1600–5000 VA · Bluetooth

MultiPlus-II3–15 kVA · inverter/charger

Quattro3–15 kVA · two AC inputs

Continuous power: the sum of the power of loads that can run at the same time (power × quantity). We compare it with the inverter’s continuous power in watts — at 25 °C or at 40 °C, from the datasheets. The power in the model name is volt-amperes: a MultiPlus-II 3 kVA delivers 2400 W at 25 °C and 2200 W at 40 °C.

Peak: motor-driven loads (fridge compressor, pump, power tools) draw extra current for a short time at start-up. If you know the starting power from the manual or the device rating plate, enter it — the calculator will add the largest start-up surplus of one load to the total (we assume two motors do not start at the same time) and compare the result with the inverter’s peak power.

Voltage: “Wiring Unlimited” recommends 12 V for inverters up to 3000 VA, 24 V up to 5000 VA and 48 V for larger systems. The “select for me” option chooses the lowest voltage at which the smallest matching model fits this rule. Battery current is calculated as power ÷ (voltage × 0.9) — 90% efficiency with margin against the maximum from the datasheets (92–96%).

Models: Phoenix Inverter VE.Direct 250–1600 VA, Phoenix Inverter Smart 1600–5000 VA, Inverter RS Smart, MultiPlus-II 3–15 kVA, Multi RS, Quattro-II 5 kVA and Quattro 3–15 kVA. We exclude the new MultiPlus-II 12/4k, 48/4k5, 48/6k5 and 48/10k, because their datasheets do not state power at 40 °C. With Multi RS and Inverter RS, the 9 kW peak power lasts 3 seconds (7 kW for 4 minutes).

What the calculator does not check: battery bank capacity, cables and fuses (for MultiPlus-II we describe these in the guide How to select an inverter/charger), parallel operation or PowerAssist. You can calculate how much energy your loads use in a day in the energy balance, and cable cross-sections in the cable calculator.

Sources

Content checked against Victron Energy documentation (datasheets and manuals) — status as of 23 September 2026. Report an error in the content · Correction log