YOUR ENERGY PROFILE.
This document contains the sizing of your future electrical installation, calculated based on your appliances.
Inventory:
Battery
To guarantee 0WH without damaging your bank (80% max discharge):
Solar
Minimum power required to recharge your consumption:
220V AC
Maximum power (with 25% safety margin).
12V Cable Sizing Guide
Use this professional reference table to select the correct gauge (mm²) for your cables. For 12V in a van, the maximum tolerated voltage drop is 3%. Always use multi-stranded flexible automotive wire.
| Current (A) | Round trip < 2m | Round trip 4m | Round trip 6m |
|---|---|---|---|
| 5A (LEDs, USB) | 1.5 mm² | 2.5 mm² | 4 mm² |
| 10A (Fridge, Pump) | 2.5 mm² | 4 mm² | 6 mm² |
| 20A (Heater) | 4 mm² | 10 mm² | 10 mm² |
| 50A (DC/DC Booster) | 10 mm² | 16 mm² | 25 mm² |
| 100A (Inverter) | 25 mm² | 35 mm² | 50 mm² |
Fuse Sizing
The fuse protects the wire, not the appliance. Always place it as close to the power source as possible (battery or busbar).
- Wire 1.5 mm² → Max fuse 10A
- Wire 2.5 mm² → Max fuse 20A
- Wire 4 mm² → Max fuse 30A
- Wire 6 mm² → Max fuse 40A
- Wire 10 mm² → Max fuse 60A
SCHÉMA ÉLECTRIQUE
PANNEAUX SOLAIRES
0W
REGULATEUR MPPT
BATTERIE AUXILIAIRE
0 Ah
Lithium LiFePO4
BOÎTE À FUSIBLES 12V
Pompe, Leds, Frigo...
CONVERTISSEUR 220V
NON REQUI
SHOPPING LIST
Where to find this equipment? Here is the community-approved selection.
12V 6-way Fuse Box
Mandatory protection
Digital Multimeter
Test your connections
Heavy Duty Crimping Tool
For perfect lugs
Heat Shrink Tubing
Insulation and safety
Comparison table
| Panel watts | Wh/day summer (US SW) | Wh/day summer (NE) | Wh/day winter (SE) |
|---|---|---|---|
| 100W | 650-750 | 500-600 | 250-350 |
| 200W | 1,300-1,500 | 1,000-1,200 | 500-700 |
| 300W | 1,950-2,250 | 1,500-1,800 | 750-1,050 |
| 400W | 2,600-3,000 | 2,000-2,400 | 1,000-1,400 |
About this tool
Solar Panel Size Guide for Sprinter Van Builds
The Mercedes Sprinter is the gold standard of van life platforms — its flat roof and generous dimensions allow for a serious solar installation. Here's how to determine the right panel count and wattage for your specific Sprinter and usage pattern.
Usable Roof Area by Sprinter Version
| Sprinter Version | Gross Roof Area | Usable for Solar | Max Practical Wattage |
|---|---|---|---|
| 144" WB (L1) | ~2.2 m² | ~1.8 m² | 300-400W |
| 170" WB (L2) | ~2.8 m² | ~2.5 m² | 500-600W |
| 170" WB Extended (L3) | ~3.4 m² | ~3.0 m² | 600-800W |
| 4x4 with roof rack | +1-2 m² | Up to 5 m² | 800-1,200W |
Subtract space for: MaxxFan duct (≈0.15 m²), fan (≈0.04 m²), roof rack mounting feet, and rooftop AC if fitted.
How Much Solar Does Your Sprinter Need?
For a couple working remotely full-time in a 170" WB Sprinter:
- Fridge (Dometic CFX3 45L): ~400Wh/day
- 2× laptops + monitors: ~600Wh/day
- Lighting, fans, phone charging: ~200Wh/day
- Starlink or 5G router: ~220Wh/day
- Total: ~1,420Wh/day
With 500W of solar and 5h peak sun (summer UK/France): 500 × 5 × 0.85 = 2,125Wh/day — comfortable with 700Wh/day surplus to top up batteries.
In winter (2h PSH): 500 × 2 × 0.85 = 850Wh/day — short by 570Wh, requiring supplemental charging via DC-DC.
Panel Configuration Options for a 170" WB Sprinter
| Config | Total Watts | Panels | Wiring |
|---|---|---|---|
| 3× 200W rigid | 600W | 3 panels | Series or parallel |
| 2× 300W rigid | 600W | 2 panels | Series |
| 4× 150W semi-flex | 600W | 4 panels | 2S×2P |
| 2× 400W rigid (slim) | 800W | 2 panels | Series |
Recommendation: 2× 300W rigid monocrystalline panels in series (gives 24V string input to MPPT). Clean installation, maximum efficiency, fewest roof penetrations.
MPPT Sizing for 500-600W on a Sprinter
For 600W in series (2× 300W, Voc ≈ 40V × 2 = 80V string):
- Use Victron SmartSolar MPPT 100/50 (100V max input, 50A output, up to 700W in 12V)
- Total cost: ~$200-280
For 800W+: Victron SmartSolar MPPT 150/60 or 150/70 needed.
Expert tip: Both panels in series means reduced current and smaller gauge cable between roof panels and MPPT — 4mm² is sufficient for a series-wired 600W string, vs 6mm² if wired in parallel. Series wiring also means each panel shading affects only that panel, not the entire string (with modern MPPTs).