Example calculation for your setup
Results based on a typical use case
| Appliance | Power | Usage/day | Wh/day |
|---|---|---|---|
| Compression fridge | 45W | 24h | 1080 |
| LED lighting | 20W | 4h | 80 |
| Water pump | 30W | 0.5h | 15 |
| Phone charging | 15W | 2h | 30 |
| Daily consumption | 1205 Wh | ||
Adjust these values with the calculator below
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
| Component | Model | Specs | Price |
|---|---|---|---|
| Heated LiFePO4 | Redodo 12V 400Ah | 400Ah, heated BMS, -20°C | ~€850 |
| Solar Panels | Renogy 3x200W Mono | 600W total, roof mount | ~€420 |
| MPPT Controller | Victron SmartSolar 150/35 | 35A, 150V input max | ~€220 |
| DC-DC Charger | Victron Orion-Tr Smart 12/12-30 | 30A, Bluetooth | ~€160 |
| Pure Sine Inverter | Victron Phoenix 12/3000 | 3000W continuous | ~€650 |
| Diesel Heater | Vevor / Chinese 2kW | 2kW, LCD thermostat | ~€180 |
| Fuse Box | Blue Sea ST Blade 12 | 12 circuits | ~€45 |
| Battery Monitor | Victron SmartShunt 500A | Bluetooth, VictronConnect | ~€75 |
| Battery Cables | 50mm² + ANL lugs | Heavy-duty set | ~€50 |
| Solar Cables | MC4 + 6mm² | 20m, Y-connectors | ~€40 |
| Battery Insulation | Armaflex 19mm | Complete battery box | ~€40 |
| Heated Blanket | 12V 150x80cm | 50W, thermostat | ~€45 |
| Outlets + USB | USB-C PD + 12V x4 | Complete kit | ~€50 |
| LED Lighting | Dimmable spots + strip | 12-point kit | ~€55 |
| Miscellaneous | Fuses, conduit, lugs, mounts | Pro wiring kit | ~€70 |
| **TOTAL** | **~€2,950** |
About this tool
The Winter Challenge: When Cold Tests Your Limits
Winter vanlife in the Alps, Pyrenees, or Scandinavia is magical. But it's also the most demanding environment for an electrical system.
The 4 Enemies of Winter Electricity
- Solar production drops 3-4x — In December in central Europe, a 100W panel produces ~100-150Wh/day vs 500-600Wh in July
- LiFePO4 won't charge below 0°C — The lithium chemistry freezes and cells degrade if you force charging
- Consumption increases — Diesel heater (10-25W electrical), more lighting, more cooking
- Condensation — Moisture attacks electrical connections and can cause short circuits
The Solution: Heated BMS
LiFePO4 batteries with built-in heated BMS (Redodo, LiTime, Power Queen) have a heating element that warms cells before accepting charge. Cost: €50-80 more than standard. This is NON-NEGOTIABLE for winter.
Winter Power Consumption
- Diesel heater: 24h x 15W = 360Wh (electrical draw only)
- 50L fridge: 420Wh
- LED lighting (short days, 14h): 100Wh
- Laptop + Starlink: 800Wh (if digital nomad)
- Ventilation (moisture removal): 50Wh
- Water pump: 15Wh
- Coffee machine: 80Wh
- 12V heated blanket: 8h x 50W = 400Wh
- Total: ~2,225Wh/day
Why 600W Panels, Not 400W
In December in central Europe (2.5h PSH): 600W x 2.5h x 0.8 = 1,200Wh/day. Not enough alone, but combined with 30A DC-DC while driving 1h/day (360Wh), you reach 1,560Wh. The ~665Wh deficit draws from the 400Ah reserve (4,800Wh).
