Inverter & Charger Setup

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Inverter & Charger Setup

Getting your MultiPlus or Quattro up and running. Select your model below — the setup is nearly identical, with a few key differences called out.

MultiPlus-II
Quattro
1

DC Wiring — Battery Connection

Connect the MultiPlus-II DC terminals to your battery bank. Positive to B+ and negative to B–. Use the correct cable size for your model — the 12/3000 requires minimum 70mm² (2/0 AWG), the 24/3000 minimum 35mm² (2 AWG).

Fuse required: Install a MEGA or ANL fuse at the battery end of the positive cable. See the manual for the correct amperage for your model.
2

AC Wiring — Shore Power & Loads

Connect shore power (grid or generator) to the AC-IN terminals. Connect your AC loads to the AC-OUT 1 terminals. AC-OUT 1 passes through power when shore is present and inverts when it’s not — this is where critical loads go.

AC-OUT 2: Only powered when shore/generator is present — use this for non-essential loads like water heaters that don’t need battery backup.
3

VE.Bus Connection to Cerbo GX

Connect the MultiPlus-II to your Cerbo GX using a standard Cat5 RJ45 cable via the VE.Bus port. This gives the Cerbo full control and visibility over the inverter/charger — charge current, mode switching, and real-time monitoring.

4

Configure with VEConfigure

Download Victron’s free VEConfigure software to set charge current, battery type, AC input current limit, and ESS settings. Connect your laptop via a VE.Bus to USB interface (MK3-USB), available from JonssonTech.

LiFePO4 users: Set battery type to Lithium and configure the charge voltages to match your BMS specs — typically 14.2V absorption, 13.5V float for 12V systems.
5

Power On & Test

Switch on the DC breaker, then press the MultiPlus’s front panel switch to ON. Verify the unit inverts correctly with no AC input connected, then connect shore power and confirm it switches to charge mode. Check the Cerbo GX display for live status.

1

DC Wiring — Battery Connection

Same as the MultiPlus — connect DC+ and DC– to your battery bank with appropriately sized cables and a fuse at the battery. The Quattro 24/5000 requires minimum 70mm² (2/0 AWG) DC cable.

Fuse required: Install a MEGA or ANL fuse at the battery end of the positive cable. Check the Quattro manual for the correct rating for your model.
2

AC Wiring — Two AC Inputs

The Quattro has two AC inputs. Connect shore power (grid or dock pedestal) to AC-IN 1. Connect your generator to AC-IN 2. The Quattro automatically prioritises AC-IN 1 and only switches to AC-IN 2 (generator) when AC-IN 1 is absent or below spec.

Generator auto-start: Once your Cerbo GX is connected, configure generator auto-start under Settings → Generator. The Cerbo’s relay output connects to your generator’s remote start terminal.
3

VE.Bus Connection to Cerbo GX

Connect the Quattro to your Cerbo GX via the VE.Bus port (Cat5 RJ45 cable). For stacked Quattros (parallel or split-phase), daisy-chain the VE.Bus between units and connect the last one to the Cerbo.

4

Configure with VEConfigure

Use Victron’s VEConfigure software to set charge currents, battery type, AC input current limits for each input, and PowerAssist settings. Connect via MK3-USB interface. For stacked units, configure the master first.

AC input current limit: Set this to 80% of your shore power breaker (e.g., 24A on a 30A circuit) so the Quattro’s PowerAssist prevents tripping the pedestal breaker.
5

Power On & Test Both AC Inputs

Power on, then test with AC-IN 1 only, AC-IN 2 only, and no AC input (inverting). Verify the Cerbo GX shows the correct source status for each scenario. Run a generator test to confirm auto-switching works correctly.

Need help with configuration?

VEConfigure and VE.Bus settings can be tricky. Our team is happy to walk you through it.

Contact JonssonTech →