Solar Panels for a Campervan or Motorhome: Complete System Guide (2026)
A solar system is the single most impactful upgrade you can make to a campervan or motorhome. It eliminates hookup fees, gives you genuine freedom to wild camp without running the engine, and powers everything from the fridge to a laptop without noise or fumes.
This guide covers every component and decision, from choosing panel size to wiring the battery correctly.
In this guide, you'll learn:
What You Actually Need Solar For
Before sizing a system, list your actual daily electrical loads:
| Appliance | Typical draw | Daily hours | Daily kWh |
|---|---|---|---|
| 12V compressor fridge (60L) | 40W average | 24 hrs | 0.96 kWh |
| LED lighting (4 strips) | 20W total | 5 hrs | 0.10 kWh |
| Phone charging (x2) | 20W total | 3 hrs | 0.06 kWh |
| Laptop | 45W | 3 hrs | 0.14 kWh |
| Water pump | 60W | 0.5 hrs | 0.03 kWh |
| 12V fan | 15W | 4 hrs | 0.06 kWh |
| Typical total | — | — | ~1.4 kWh/day |
Most campervan builds need 1–3 kWh/day. Size your solar system and battery around this number, with 2–3 days of battery autonomy for cloudy periods.
System Sizes by Use Case
| Use case | Panels | Battery | Daily generation (UK summer) | Approx cost |
|---|---|---|---|---|
| Weekend trips, minimal use | 100W | 50–80Ah 12V | 0.4–0.6 kWh | £200–£400 |
| Regular camping, fridge + basics | 200W | 100Ah LiFePO4 | 0.8–1.2 kWh | £500–£800 |
| Full-time van life, laptop + fridge | 300–400W | 200Ah LiFePO4 | 1.2–2.4 kWh | £900–£1,600 |
| All-season or large motorhome | 400–600W | 200–300Ah LiFePO4 | 1.6–3.6 kWh | £1,400–£2,500 |
Choosing Your Panels
Three panel types suit campervans:
- Rigid monocrystalline panels — most efficient (20–22%), lowest cost per watt, longest life. The right choice if you have flat unobstructed roof space. 100W panel: £40–£70. Fixed with roof brackets.
- Slim/low-profile rigid panels — 15–30mm thinner, better aerodynamics. Worth the small premium on motorhomes over 70mph. 100W: £60–£100.
- Flexible panels — curve to roof profile, adhesive-mounted. Lighter and lower-profile. Trade-off: shorter lifespan (5–8 years vs 20+ for rigid), lower efficiency, heat management issues. Only use on curved roofs where rigid panels won't fit.
Avoid flexible panels if you can fit rigid — the lifespan and efficiency difference is significant over a van's life.
Battery: The Most Important Decision
The battery is the heart of the system and where most van builds go wrong. Two realistic choices in 2026:
AGM lead-acid — cheap upfront (100Ah: £80–£120) but only 50% usable capacity (so 100Ah is really 50Ah useful), heavy (28–30kg), shorter life (300–500 cycles), needs ventilation. Only worth choosing if budget is very tight.
LiFePO4 lithium — 100% usable capacity, half the weight (12–14kg), 3,000–5,000 cycles (8–15 years), no ventilation needed, can be charged at any state of charge. 100Ah: £150–£250. This is the correct choice for any build you plan to use seriously.
A 100Ah LiFePO4 battery stores 1.28 kWh of usable energy at 12.8V nominal. A 100Ah AGM battery stores only 0.6 kWh usable. You need twice the AGM capacity to match LiFePO4 — which erases the cost advantage entirely once weight and replacement costs are factored in.
Complete Component List
| Component | Recommended spec | Budget (200W system) | Notes |
|---|---|---|---|
| Solar panel(s) | 200W mono rigid | £80–£140 | 2× 100W or 1× 200W |
| MPPT charge controller | 20–30A MPPT | £30–£60 | MPPT essential for LiFePO4 |
| LiFePO4 battery | 100–200Ah 12V | £150–£350 | Include BMS |
| DC fuse box | 6–8 way with fuses | £20–£40 | One fuse per circuit |
| Battery isolator switch | 100A rated | £10–£20 | Essential safety item |
| Inverter (if needed) | 300–600W pure sine | £30–£70 | Only if using 230V devices |
| Cable, fuses, MC4 connectors | 6mm² solar; 16mm² battery | £25–£45 | Do not undersize |
| Battery monitor | Victron BMV-712 or similar | £50–£90 | Highly recommended |
Wiring Overview
The wiring sequence: panels → MPPT controller → battery (with fuse at battery) → DC fuse box → loads. All connections fused at the battery end. Cable sizes: 6mm² from panel to controller, 10–16mm² from controller to battery, 16mm² from battery to fuse box.
Keep the battery-to-controller cable as short as possible — voltage drop over long runs reduces charging efficiency. Route panel cables through the roof using waterproof cable entry glands, sealed with silicone.
For a deeper dive on system sizing and off-grid calculations, the off-grid solar sizing guide covers all the load calculations in detail. For a portable setup that avoids wiring entirely, see the portable power station guide →
Frequently Asked Questions
How many solar panels do I need for a campervan?
A single 200W panel covers most campervan needs in UK summer — fridge, lighting, phone and laptop charging from a 100Ah LiFePO4 battery. For full-time van life or winter use, 300–400W with a 200Ah battery gives genuine independence across most weather conditions. A 100W starter system is fine for weekend use without a fridge.
What size battery for a campervan solar system?
A 100Ah LiFePO4 battery (1.28 kWh usable) suits most weekend campervans. Full-time van lifers typically run 200Ah (2.56 kWh), which covers 1.5–2 days of typical use without solar input. Size for 2–3 days autonomy in your worst-case (winter, no sun) scenario.
Can I charge a campervan battery while driving?
Yes — a DC-DC charger (also called a B2B charger) connects your alternator to the leisure battery and charges it while driving. A 20–30A DC-DC charger adds 20–30Ah per hour of driving. Combined with solar, this makes most van builds genuinely energy-independent. Do not use a simple split-charge relay with LiFePO4 batteries — use a dedicated DC-DC charger that matches the LiFePO4 charge profile.
