Motorhomes come in all sizes, and the electrical system needs to match. A VW California has very different space, weight, and power requirements compared to a 10-metre A-class. This guide recommends complete Victron setups for three common motorhome sizes, with realistic budgets and product choices for each tier.
Quick Comparison: Three Tiers
| Specification | Small (VW/Compact) | Medium (Ducato/Sprinter) | Large (A-Class/American) |
|---|---|---|---|
| Typical vehicle | VW T6.1, Transit Custom | Fiat Ducato, MB Sprinter | A-class, tag-axle, RV |
| Roof space for solar | Limited (200–300W) | Moderate (300–500W) | Generous (400–800W+) |
| Battery capacity | 100–200Ah | 200–400Ah | 400–600Ah+ |
| Inverter size | 800–1,200VA | 1,600–2,000VA | 2,000–5,000VA |
| Typical daily use | 30–60Ah | 60–150Ah | 100–250Ah+ |
| Budget estimate | £1,000 – £2,000 | £2,500 – £4,500 | £4,000 – £8,000+ |
Tier 1: Small Motorhome (VW / Compact Van)
Small motorhomes and high-top campervans are limited by space and weight. Every component needs to be compact, and you can't load the roof with heavy panels. The goal is a lightweight, efficient system that covers the basics without over-engineering.
Recommended Setup
| Component | Recommendation | Est. Price |
|---|---|---|
| Solar | 1–2 x 150W panels (150–300W total) | £100 – £250 |
| MPPT Controller | Victron SmartSolar 75/15 or 100/20 | £75 – £120 |
| Battery | 100Ah LiFePO4 | £300 – £600 |
| DC-DC Charger | Victron Orion-Tr Smart 12/12-30 | £120 – £170 |
| Inverter | Victron Phoenix 12/800 or 12/1200 | £160 – £300 |
| Battery Monitor | Victron SmartShunt 500A | £55 – £80 |
| Cabling, fuses, misc | Standard install kit | £100 – £180 |
Estimated total: £910 – £1,700
Why This Setup Works
A 100Ah lithium battery provides over two days of autonomy for moderate use (LED lights, phone charging, compressor fridge, water pump). The SmartSolar 75/15 handles up to 200W of solar efficiently. The Phoenix 800VA or 1200VA inverter runs a coffee machine, laptop charger, and hair dryer (on low) without requiring the bulk or cost of a MultiPlus.
Space is the main constraint in a VW or similar. The Phoenix 800 is remarkably compact. A 100Ah lithium battery fits under a seat or in a small cupboard. The SmartSolar 75/15 is barely larger than a paperback book.
Upgrade Option
If you use the motorhome frequently or need to run higher-powered appliances, swap the Phoenix inverter for a MultiPlus Compact 12/1600/70. This adds shore power charging and automatic transfer switching, which is particularly useful on continental campsites.
Tier 2: Medium Motorhome (Fiat Ducato / Sprinter Based)
The most popular motorhome size in the UK. Ducato-based coachbuilts and panel van conversions (like the Fiat Ducato, Mercedes Sprinter, or Peugeot Boxer) offer more roof space, more payload, and typically more appliances to power. This is where a full Victron system really shines.
Recommended Setup
| Component | Recommendation | Est. Price |
|---|---|---|
| Solar | 2–3 x 175W panels (350–525W total) | £200 – £450 |
| MPPT Controller | Victron SmartSolar 100/30 or 150/35 | £130 – £230 |
| Battery | 200Ah LiFePO4 (or 2 x 100Ah) | £600 – £1,200 |
| DC-DC Charger | Victron Orion-Tr Smart 12/12-30 | £120 – £170 |
| Inverter/Charger | Victron MultiPlus 12/1600/70 | £550 – £750 |
| Battery Monitor | Victron SmartShunt 500A | £55 – £80 |
| System Monitor | Victron Cerbo GX + GX Touch 50 | £300 – £450 |
| Cabling, fuses, misc | Full install kit | £150 – £250 |
Estimated total: £2,105 – £3,580
Why This Setup Works
This is essentially the reference system from our comprehensive guide. The MultiPlus 12/1600/70 provides seamless shore/inverter switching with PowerAssist for European touring. The 200Ah battery bank and 350–525W solar array sustain full-time use in the UK summer and handle weekend use comfortably year-round.
The Cerbo GX is included at this tier because medium motorhomes typically have enough components to make centralised monitoring worthwhile. The ability to remotely check your system via VRM is especially valuable when the motorhome is in storage.
Upgrade Option
For full-time winter living, consider stepping up to a MultiPlus 12/2000/80 and 300–400Ah of lithium to handle the diesel heater's constant power draw combined with daily appliance use.
Tier 3: Large Motorhome (A-Class / American RV)
Large motorhomes have substantial electrical demands — air conditioning, residential fridges, washing machines, multiple TV screens, and comprehensive heating systems. The roof area is generous, and the chassis supports considerable weight. This is where you can build a serious off-grid power station.
Recommended Setup
| Component | Recommendation | Est. Price |
|---|---|---|
| Solar | 4 x 200W panels (800W total) | £400 – £700 |
| MPPT Controller | Victron SmartSolar 150/45 or 150/60 | £250 – £400 |
| Battery | 400–600Ah LiFePO4 | £1,800 – £3,600 |
| DC-DC Charger | 2 x Victron Orion-Tr Smart 12/12-30 | £240 – £340 |
| Inverter/Charger | Victron MultiPlus-II 12/3000/120 or Quattro 12/5000 | £900 – £2,200 |
| Battery Monitor | Victron SmartShunt 500A | £55 – £80 |
| System Monitor | Victron Cerbo GX + GX Touch 70 | £350 – £500 |
| Mains charger (backup) | Victron Phoenix Smart IP43 12/50 | £250 – £350 |
| Cabling, fuses, misc | Heavy-duty install kit | £200 – £400 |
Estimated total: £4,445 – £8,570
Why This Setup Works
The 3,000VA or 5,000VA inverter/charger can run anything you'd have at home — microwave, induction hob, air conditioning (with the 5,000VA), washing machine, and more. Two Orion-Tr Smart chargers in parallel provide 60A of alternator charging, which is appropriate for the large alternators fitted to A-class and tag-axle motorhome chassis.
With 800W of solar and 400–600Ah of lithium, you have genuine off-grid autonomy for multiple days, even with heavy use. The larger GX Touch 70 display is better suited to the dashboard or habitation area of a larger vehicle where you can mount it in a visible location.
Special Considerations for Large Motorhomes
- Dual MPPT controllers: If roof layout requires splitting panels across different orientations (e.g., front and rear slopes), use two separate MPPT controllers instead of one large one. Each controller independently tracks the maximum power point for its array.
- Generator integration: Many large motorhomes have a generator. The MultiPlus or Quattro integrates with a generator to charge batteries and power AC loads. The Quattro can accept two AC inputs (shore + generator) and switch automatically.
- 48V systems: For very large systems (6kW+ inverter, 10kWh+ battery), consider upgrading to a 48V architecture. Lower currents mean smaller cables and less voltage drop. Victron offers a full 48V product range.
Which Tier Do You Need?
The right tier depends on how you use your motorhome, not just its size:
- Weekend/holiday use, cooking on gas, no heating: Tier 1 is often sufficient even in a larger motorhome.
- Regular use, some mains appliances, campsite hookup most nights: Tier 2 is the sweet spot.
- Full-time living, extended off-grid, running high-power appliances: Tier 3 is designed for you.
Start by calculating your daily power usage to determine which tier genuinely matches your needs. Then use our price comparison tool to find the best prices on every component. You can also try our system builder tool for personalised recommendations based on your specific requirements.
