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
| Power (W) | Device alimentable | Max 12V draw | Min wire gauge |
|---|---|---|---|
| 300W | Laptop + charges | 30A | 10 AWG |
| 600W | TV, small appliances | 60A | 6 AWG |
| 1,200W | Coffee maker, microwave | 110A | 2 AWG |
| 2,000W | Standard hair dryer | 180A | 1/0 AWG |
| 3,000W | Portable induction | 270A | 2/0 AWG |
About this tool
Inverter sizing for a campervan starts with a single question: what is the highest continuous wattage device you plan to plug in? That single number drives the specification. But there's a deeper layer — inrush current, idle consumption, and efficiency curves that can turn a reasonable inverter into an energy vampire.
The fundamental calculation: Inverter Watts needed ≥ Peak continuous load watts × 1.25 safety margin. For a coffee machine (800W) + laptop charger (90W) used simultaneously: (800 + 90) × 1.25 = 1112W. A 1500W inverter gives 35% headroom for safe operation. A 1000W inverter would run at 89% load continuously — thermally stressed and likely to shut down on hot days.
Inrush current reality: AC motors (coffee grinder, blender, angle grinder, compressor motor) draw 3-6× rated power for 20-50ms on startup. A 500W angle grinder's motor spikes to 1500-3000W at startup. Inverter surge rating matters — look for "peak/surge watts" specification: a good 1500W inverter has 3000W peak. Cheap inverters with the same continuous rating often have only 1.5-2× peak — insufficient for motor loads.
Idle consumption destroys batteries: measure the standby wattage of your specific inverter before integrating it. Cheap 2000W inverters often consume 18-25W at zero load — multiply by 24h = 432-600Wh/day of wasted energy. The Victron Phoenix 2000W at 15W idle is significantly more efficient but 3× the price. The economic calculation: if your inverter runs 12h on standby per day, 5W idle difference = 60Wh/day = 21.9kWh/year. At €0.25/kWh of battery round-trip (replacement costs included), that's €5.47/year in wasted energy — trivial. The real cost is the battery cycles and solar capacity needed to cover the waste.
Pure sine wave is mandatory for van builds: modified sine wave inverters cause audible hum in laptop PSUs, can damage CPAP motor windings over thousands of hours, and reduce efficiency in any load with reactive components (transformers, capacitors, inductors — which includes virtually all modern electronics). The €20-40 price difference for pure sine wave is never worth skipping.
Installation cable sizing for 12V systems: 1000W inverter at 12V = 83A; 2000W = 167A; 3000W = 250A. Cable must be rated for peak surge current. For a 2000W inverter: 50mm² for runs under 50cm, 70mm² for 50-100cm. The ANL fuse (not blade fuse) must be within 30cm of battery positive terminal, rated 20% above inverter's maximum current draw.
Remote on/off wiring: virtually all 300W+ inverters have a remote enable terminal. Wiring this to a dedicated 12V switch at your work desk means you can cut inverter power instantly — eliminating standby consumption while you sleep or when not actively using AC loads.