Victron MultiPlus Inverter/Charger Review: Is It Worth the Cost for UK Campervans?
The Victron MultiPlus is the most popular inverter/charger in the high-end campervan market. It combines a pure sine wave inverter, a multi-stage battery charger, and a transfer switch in one unit. The headline feature is PowerAssist — it can supplement a limited shore power supply with battery power when demand spikes.
What Is the MultiPlus?
The MultiPlus is three devices in one:
- Inverter: 12V DC → 240V AC (pure sine wave)
- Battery charger: 240V AC → 12V DC (multi-stage, programmable)
- Transfer switch: Automatically switches between shore power and inverter
The Range
| Model | Inverter Power | Charger Current | Transfer Switch | Price |
|---|---|---|---|---|
| MultiPlus 12/500/20 | 500W | 20A | 16A | £250 |
| MultiPlus 12/800/35 | 800W | 35A | 16A | £330 |
| MultiPlus 12/1200/50 | 1,200W | 50A | 30A | £450 |
| MultiPlus 12/1600/70 | 1,600W | 70A | 30A | £550 |
| MultiPlus 12/2000/80 | 2,000W | 80A | 50A | £650 |
| MultiPlus 12/3000/120 | 3,000W | 120A | 50A | £900 |
Most popular size for UK campervans: 12/1200/50. It runs a microwave, toaster, and laptop simultaneously and charges the battery at 50A when on hook-up.
Installation
What You Need
| Component | Spec | Cost |
|---|---|---|
| MultiPlus unit | As chosen | £250–900 |
| Battery cable | 35mm² (for 1,200W) | £3/m |
| MEGA fuse + holder | 200A | £20 |
| Shore power inlet | 16A blue caravan socket | £25 |
| RCBO | 16A, 30mA | £20 |
| Display panel (optional) | Victron Cerbo GX or Venus GX | £150–300 |
Step-by-Step
- Mounting: Mount the MultiPlus vertically on a rigid surface. It weighs 8–12kg depending on model. Leave 10cm clearance on all sides for airflow — it generates significant heat at high loads.
- DC wiring: Run 35mm² cable from battery positive through a 200A fuse to the MultiPlus positive terminal. Run 35mm² from battery negative to MultiPlus negative terminal. Torque to 10 Nm.
- AC input: Wire the shore power inlet through a 16A RCBO to the MultiPlus AC input terminals.
- AC output: Wire the MultiPlus AC output to your 240V distribution board (1.5mm² cable, RCD-protected).
- Grounding: Connect the MultiPlus chassis ground to the van's chassis ground. Connect the AC neutral to ground (Victron's instruction manual specifies the correct configuration for mobile systems).
- Configuration: Configure the MultiPlus using a laptop (VictronConnect via USB) or a Cerbo GX display. Set battery type (LiFePO4), charge profile (14.2V absorption, 13.8V float), and PowerAssist settings.
Configuration Settings (for LiFePO4)
| Parameter | Setting | Why |
|---|---|---|
| Battery type | LiFePO4 | Uses correct charge profile |
| Absorption voltage | 14.2V | Standard LiFePO4 absorption |
| Float voltage | 13.5V | Maintains battery at full charge |
| Absorption time | 4 hours | Ensures full charge |
| Repeated absorption | Every 7 days | Prevents capacity drift |
| Low battery shutdown | 11.5V | Protects battery from over-discharge |
| Restart voltage | 13.0V | Resumes after battery recovers |
Key Features
Multi-Stage Battery Charger
When connected to shore power, the MultiPlus charges your battery through a programmable multi-stage profile:
- Bulk: Constant current (up to 50A on the 12/1200/50) until the battery reaches absorption voltage
- Absorption: Constant voltage (14.2V) for a set time — typically 4 hours
- Float: Constant voltage (13.5V) to maintain full charge without overcharging
- Storage: Lower voltage (13.2V) for long-term storage — prevents battery stress
The charger is temperature-compensated (if you connect a temperature sensor) and silent (fanless at low charge rates, the fan runs at medium rates).
PowerAssist
This is the MultiPlus's defining feature. When on shore power (e.g., a 10A campsite hook-up), and you turn on a high-power appliance (a 2kW kettle), the MultiPlus supplements the shore power with battery power to meet the demand without tripping the campsite breaker.
Example: You are on a 10A hook-up (2,400W). You turn on a 2kW kettle. Your fridge is drawing 200W. Total demand: 2,200W — within the hook-up capacity. But if you turn on the kettle + a toaster (1,500W), total demand is 3,700W — exceeds the 2,400W hook-up. The MultiPlus supplies the extra 1,300W from the battery.
Why this matters: UK campsite hook-ups are often limited to 10A or 16A. Without PowerAssist, you would trip the breaker every time you tried to use the kettle and the toaster together. With PowerAssist, you can run both — the MultiPlus manages the load seamlessly.
Transfer Switch
When shore power is connected, the MultiPlus passes it through to your 240V outlets (inverter off). When shore power disconnects, the MultiPlus switches to inverter mode in 20ms — fast enough that computers and clocks do not reset.
Real-World Performance
| Scenario | What Happens |
|---|---|
| 800W microwave + 100W laptop on hook-up (16A) | Pass-through: microwave runs from shore power, laptop from same. PowerAssist not needed. |
| 2kW kettle + 1.5kW toaster on 10A hook-up | PowerAssist engages: 2.4kW from shore + ~1kW from battery = 3.4kW total. Kettle and toaster both run. |
| Off-grid, microwave for 3 minutes | Inverter: 1,000W draw (microwave input), battery provides ~83A. 100Ah battery loses ~5Ah. |
| Off-grid, watching TV for 3 hours | Inverter: 60W draw, 5A from battery. Negligible drain. |
| Battery low, shore power connected | Charger: full 50A until absorption, then 10A float. 100Ah battery charges from 50% to 100% in ~1.5 hours. |
Noise
The MultiPlus uses a temperature-controlled fan. At low loads (<300W), the fan does not run — the MultiPlus is silent. At 800W+ (microwave), the fan runs at medium speed — audible but not loud (40dB at 1m). At full load (1,200W continuous), the fan runs at full speed — noticeable (50dB at 1m). This is much quieter than budget inverters whose fans run constantly.
Efficiency
| Load | Efficiency | Notes |
|---|---|---|
| 100W (TV + laptop) | 94% | Very good — 6W lost as heat |
| 500W (coffee machine) | 93% | Good |
| 1,000W (microwave) | 91% | Acceptable — 90W lost as heat |
| Idle (no load, inverter on) | 7W | Very low for this size of inverter |
Comparison to Alternatives
| Feature | Victron MultiPlus 12/1200/50 (£450) | Basic Inverter + Charger (£200–300) | Other All-in-One (MPP Solar, £300–400) |
|---|---|---|---|
| Inverter quality | Excellent (pure sine, clean waveform) | Variable (often modified sine) | Good (pure sine, less clean) |
| Charger quality | Excellent (multi-stage, programmable) | Variable (often single-stage) | Good (multi-stage, limited config) |
| PowerAssist | ✓ Yes | ✗ No | ✗ Usually no |
| Transfer switch | ✓ Yes (20ms) | ✗ Manual or no | ✓ Yes (slower, 30–50ms) |
| Remote monitoring | ✓ Via Cerbo/Venus + VRM | ✗ No | ✗ Sometimes |
| Configuration | VictronConnect (excellent) | DIP switches or no | Screen or app (OK) |
| Support | Excellent (Victron UK distributor) | Variable (brand dependent) | Limited (Chinese brands) |
| Resale value | High (buyers know Victron) | Low | Low |
The MultiPlus is more expensive but offers: PowerAssist (unique feature), better support, better configuration, and higher resale value. For full-time van lifers who use hook-up regularly, PowerAssist alone can justify the premium.
The Downside
| Disadvantage | What It Means |
|---|---|
| Price | 2–3× more than a basic inverter + charger |
| Weight | 8–12kg — significant for payload |
| Size | 375 × 214 × 110mm — takes up cabinet space |
| Setup complexity | Configuration requires a laptop or Cerbo GX |
| Fan noise at high load | 50dB — loud in a small van at night |
| No Bluetooth on base unit | You need a Cerbo/Venus for remote monitoring |
Should You Buy a Victron MultiPlus?
| Buy It If... | Skip It If... |
|---|---|
| You use hook-up regularly (PowerAssist is valuable) | You are almost always off-grid |
| You want seamless shore power transfer | You are on a tight budget |
| You value build quality and support | You need a simple inverter only |
| You are building a premium conversion with resale value | Your power needs are minimal (300W or less) |
| You already have Victron equipment (ecosystem bonus) | You do not mind managing a separate charger |
My verdict: If you use hook-up even occasionally, PowerAssist makes the MultiPlus worth the premium. If you are off-grid 95% of the time, a basic pure sine wave inverter + separate charger saves you £200–250. For full-time van lifers who mix off-grid and campsite living, the MultiPlus is the best inverter/charger on the market.
FAQ
Q: Can the MultiPlus charge the battery and run the inverter at the same time? A: Yes. When on shore power, the MultiPlus charges the battery AND passes through shore power to the 240V outlets. The charger and pass-through operate simultaneously.
Q: Does the MultiPlus work with LiFePO4 batteries? A: Yes. The charge profile is fully programmable. Set absorption to 14.2V, float to 13.5V, and enable the LiFePO4 preset.
Q: Can I monitor the MultiPlus from my phone? A: Not directly (the base unit uses USB only). You need a Cerbo GX (£250) or Venus GX (£150) connected to the MultiPlus, then the VRM portal/app shows all data.
Q: What size MultiPlus do I need for a microwave? A: The 12/1200/50 runs most 700–900W microwaves. Check the microwave's input power (not output power). An 800W microwave typically draws 1,000–1,200W input. The MultiPlus can handle this for the 2–5 minutes a microwave runs.
Q: Can I install a MultiPlus myself? A: Yes, if you are comfortable with high-current 12V wiring and basic 240V wiring. The configuration requires a laptop with VictronConnect. For the 240V AC connections, have a qualified electrician check your work.
