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
| 12V | 24V | 48V | |
|---|---|---|---|
| Cable for 3000W | 4/0 AWG (€18/m) | 2/0 AWG (€9/m) | 4 AWG (€4/m) |
| DC appliance choice | Huge ✅ | Limited ⚠️ | Very limited ❌ |
| Inverter choice | Excellent | Good | Good (premium) |
| Complexity | Low | Medium | High |
| Best for | Weekend, <150Ah/day | — | Full-time, >200Ah/day |
About this tool
The Voltage Decision Explained Simply
Higher voltage = lower current for the same power. At 12V, a 2400W inverter draws 200A. That same 2400W at 48V draws only 50A. Less current means thinner cables, smaller fuses, and less heat loss. But 48V means fewer DC appliances, more expensive batteries, and a steeper learning curve.
12V: The Safe Default
12V dominates the van life market because the entire ecosystem is built around it. Every compressor fridge (Dometic CFX, BougeRV, Alpicool), every water pump (Shurflo, Seaflo), every diesel heater (Webasto, Espar) runs natively on 12V. Finding a 12V component from any supplier on Amazon or Ali Express takes 30 seconds. Victron, Renogy, Bluetti — all their best equipment has 12V versions. The downside: at 12V, a 3000W inverter needs 250A cable runs, which means expensive 4/0 AWG copper and chunky bus bars.
24V: Rarely Worth It
24V cuts current in half vs 12V, reducing wiring costs. But the DC appliance selection shrinks dramatically — most 12V fridges, heaters, and pumps don't have 24V versions. You'd need step-down converters everywhere, which add cost and failure points. The only real case for 24V is an existing truck or coach that's already 24V. For new builds, skip it.
48V: The Future for High-Power Builds
A 48V system running 3000W+ continuous makes sense when your daily consumption exceeds 200Ah at 12V equivalent. EG4, Epoch, and Pylontech sell 48V lithium batteries purpose-built for this. Victron's 48V Multiplus II inverter-charger is widely considered the best all-in-one for serious van builds. The Victron 48/5000 handles 5000W continuous and weighs 28kg — mount it close to the battery bank. For DC appliances, a 48V to 12V DC-DC converter (Victron Orion 48/12-30A) powers fridges and heaters cleanly.
Wiring Cost Comparison (300Ah system, 3m cable runs)
At 12V with 3000W inverter: need 4/0 AWG at ~€18/meter = €108 just for the main run. At 48V with same 3000W inverter: need 4 AWG at ~€4/meter = €24. The cable savings on a full build add up to €400-700.
Bottom Line by Use Case
Weekend warrior with <100Ah daily use: 12V, done. Couple working remotely full-time with 150-250Ah daily use: 12V if simplicity matters, 48V if wiring budget is tight. High-end conversion with air con and induction cooktop: 48V only — you'll need 5000W+ inverter and 48V is the only practical choice.