meta_description: Complete guide to off-grid power in UK campervans. Solar panel sizing, battery selection, wiring diagrams, and real-world power consumption data. Updated 2026.
Pro Tips from Real Van Lifers
- Always keep a spare key fob for your van's doors and locks
- Invest in a good quality multi-tool — it's the most used item in any van
- Label everything with masking tape during build, then permanent markers later
- Keep a small first aid kit accessible, not buried in storage
- Have a backup power source (portable battery) for phone navigation
- Keep wet wipes and a small towel in the glove box for quick cleanups
- Use door wedge chocks on uneven ground for extra stability
- Keep a small dictionary of local Welsh/Cornish words if traveling to those regions
Seasonal Considerations for UK Van Life
Spring (March-May): Great time for wild camping as days get longer. Still possible to get rain — keep waterproofing gear handy.
Summer (June-August): Peak season — campsites fill fast. Can get very warm in vans — invest in roof vents and fans. Late sunset (10pm) means more light for exploring.
Autumn (September-November): Fewer crowds, great for solitary camping. Leaves fall making single-track roads slippery.
Winter (December-February): Shortest days (sun sets by 4pm in December). Condensation management is critical — vent windows slightly. Keep de-icer in the glove box.
Last updated: May 2026 | Reading time: 20 min
Why Power Matters
Without power, your van is a box with a bed. With power, it's a home — fridge running, lights on, phone charging, heater working. This guide tells you exactly what to build.
Battery Options Compared
Lithium (LiFePO4) — 2026 Recommendation
100Ah lithium battery: £400-500
- 90% usable capacity (90Ah) vs 50% for lead-acid
- 2,000-5,000 cycles
- Weight: 10-12kg vs 30kg for equivalent lead-acid
- No maintenance
- Built-in BMS (battery management system)
200Ah lithium: £800-1,000
- Two 100Ah batteries in parallel
- 180Ah usable
- Enough for a full-time UK winter
Lead-Acid / AGM
AGM 100Ah: £200-300
- 50% usable (50Ah)
- 500-1,000 cycles
- Weight: 30kg
- Needs equalisation charging
- Worse performance in cold
Verdict: If you can afford the upfront cost, go lithium. The savings over the lifespan are significant.
Solar Panel Sizing
UK Reality Check
UK isn't the Sahara. The average UK receives 3-4 hours of equivalent sunlight per day, depending on season.
| Month | Average Solar Hours/Day |
|---|---|
| January | 1.5 |
| February | 2.0 |
| March | 3.0 |
| April | 3.5 |
| May | 4.5 |
| June | 5.0 |
| July | 4.5 |
| August | 4.0 |
| September | 3.0 |
| October | 2.5 |
| November | 1.8 |
| December | 1.5 |
Recommended Sizing
Solo traveller: 100W solar, 100Ah lithium Couple: 200W solar, 200Ah lithium Family: 400W solar, 400Ah lithium
Panel types:
- Monocrystalline (lightweight, efficient) — preferred
- Polycrystalline (cheaper, less efficient) — budget option
- Flexible panels — £100-200, mount on curved roofs
Inverter Sizing
| Use Case | Inverter Size |
|---|---|
| Lights, phone charging, fridge | 300-500W pure sine |
| Adding a microwave | 1,000-1,500W pure sine |
| Power tools, hairdryer | 2,000-3,000W pure sine |
Pure sine vs modified sine: Always go pure sine. Your electronics (especially fridge and laptop) will thank you.
Charging Your Battery
1. Solar (primary)
MPPT charge controller — 30A minimum. Must be MPPT, not PWM (MPPT is 30% more efficient).
2. Alternator (secondary)
DC-DC charger while driving. Redarc or Victron unit, £150-300. Charges from your alternator — keeps battery topped up on road trips.
3. Mains (campsites)
10A or 13A charger from hook-up. In most cases, the inverter doubles as a charger.
Power Consumption Chart
| Device | Watts | Hours/Day | Wh/Day |
|---|---|---|---|
| LED lights (x4) | 12W | 4h | 48 |
| Fridge (12V) | 30W | 18h | 540 |
| Phone charging | 10W | 2h | 20 |
| Laptop | 45W | 3h | 135 |
| Water pump | 25W | 0.5h | 12.5 |
| Roof fan | 5W | 8h | 40 |
| TOTAL (minimal) | ~600Wh/day | ||
| TOTAL (comfortable) | ~1,200Wh/day |
Wiring Essentials
- Battery to fuse box: 16mm² cable, 100A fuse within 150mm
- Fridge circuit: 6mm², 30A fuse
- Lighting circuit: 3mm², 10A fuse
- Inverter to battery: 16mm², 150A fuse
- Solar to MPPT: 4mm², rated for your panel's short-circuit current
Common Mistakes
- PWM instead of MPPT — wastes 30% of your solar potential
- No fuse on positive lead — fire risk
- Under-sieving electrics — 100Wh per person minimum for a comfortable life
- Forgetting the roof fan — essential for condensation control
- Buying the wrong cable — use tinned copper, not bare copper (corrodes faster)
Need heating too? Check our campervan heating guide. Planning a build? See our van conversion guide.
