Campervan Electrical Fire Safety: How to Prevent and Survive an Electrical Fire

Electrical fires are the most serious risk in campervan wiring. Unlike a mechanical breakdown, an electrical fire can start while you are asleep, spread quickly through an insulated van, and leave you with no safe exit. The good news is that almost every campervan electrical fire is preventable — and it is prevented by doing the fundamentals correctly.

This guide covers the three main causes of electrical fires in campervans, how to build a fire-safe system, and what to do if a fire starts despite your precautions.

For the specific technical detail on fusing and cable sizing, see our fuse sizing guide and wire gauge calculator.

The Three Causes of Campervan Electrical Fires

1. Unfused or Under-Fused Cables

This is the leading cause. A cable that is not fused — or fused above its current rating — can carry more current than its insulation can handle. The cable heats up, the insulation melts, the bare copper contacts nearby materials, and a fire starts.

How to prevent it:

• Every positive cable must have a fuse at its source
• The fuse must be rated lower than the cable's maximum current capacity
• The fuse must be within 30cm of the battery or power source

See our fuse sizing guide for the correct fuse for every cable size.

2. Poor Connections and Loose Terminals

A loose or poorly made connection has higher resistance than a solid connection. Under current, resistance creates heat. A crimp that has partially pulled out, a terminal bolt that has vibrated loose, or a fuse holder with corroded contacts will all generate heat under load.

Over time, heat causes further degradation — oxidation increases resistance, which increases heat, which increases oxidation. This is a runaway process that ends in a fire if not caught.

How to prevent it:

• Use quality ring terminals, correctly crimped (ratchet crimper, correct size die)
• Torque all bolt-down connections to specification
• Check and re-torque all connections annually
• Look for discolouration or melting around any connection — these are the warning signs
• Use tinned copper cable, which resists corrosion better than bare copper

3. Cable Damage and Chafing

Cables that rub against sharp metal edges, get pinched by moving panels, or run through holes without grommets will eventually have their insulation worn through. A bare conductor touching the van's metal body is a direct short — potentially hundreds of amps flowing through an undamaged section of cable until the fuse (hopefully) blows.

How to prevent it:

• Use a rubber grommet at every hole drilled through metal
• Route cables in conduit through the floor and behind panels
• Use P-clips to support cables at regular intervals — no sagging, no contact with metal
• Avoid routing cables near moving parts (sliding door, hinges, seat mechanisms)

See our cable routing guide and earth bonding guide.

Warning Signs to Take Seriously

These signs indicate a developing problem before it becomes a fire:

• Warm cables: Any cable that is warm to the touch during normal operation is either undersized or has a developing fault. Investigate immediately.
• Discolouration at connections: Browning or blackening around a terminal or fuse holder indicates arcing or excessive heat.
• Intermittent electrical faults: Appliances cutting out, lights flickering, or the battery monitor showing unexplained current draw — all can indicate a partial short circuit developing.
• Burning smell: A distinctive sweet/acrid smell of hot insulation. Do not ignore this. Find the source before continuing use.
• Fuses blowing repeatedly: Never just replace a blown fuse without finding out why it blew. See our fuse keeps blowing guide.

Fire Prevention Checklist

Wiring Design

• Main battery fuse within 30cm of battery positive
• Every positive circuit cable individually fused
• Fuse ratings match cable gauge (never exceed cable capacity)
• Inverter has its own dedicated ANL fuse on short cable direct to battery
• All cables sized for their maximum expected load with safety margin

Cable Installation

• Grommet at every panel penetration
• Cables in conduit where they run through floor or roof
• P-clips at maximum 300mm intervals in accessible locations
• No cables in contact with sharp metal edges
• No cables routed near moving parts

Connections

• Ratchet crimp on every ring terminal
• All bolt-down connections torqued and checked
• No temporary or taped connections in permanent installation
• Fuse holders clean, correctly rated, and fully seated

Ongoing

• Annual connection check and re-torque
• Monthly visual inspection for warm cables, discolouration
• Smoke detector fitted in van interior
• Appropriate fire extinguisher accessible

Fire Extinguishers for Campervans

You need the right extinguisher for an electrical fire. The wrong type can make things worse.

Best choice: CO₂ (carbon dioxide) extinguisher
CO₂ leaves no residue, is safe on electrical equipment, and is effective on class B and electrical fires. For a campervan, a 1kg CO₂ extinguisher (£25-40) is the minimum. Mount it near the exit — not inside a sealed cabinet.

Second choice: Dry powder extinguisher
Effective but leaves a powder residue that damages everything it touches. Better than nothing for an electrical fire, but CO₂ is preferred.

Not suitable: Water and foam extinguishers
Do not use water on an electrical fire — it conducts electricity. Do not use foam on an electrical source.

Inspect and service the extinguisher according to manufacturer guidance (typically annually).

Smoke Detectors

Fit at least one 9V battery-powered smoke detector in the habitation area. Mount it on the ceiling, away from the kitchen area (to avoid cooking-related false alarms). Test monthly using the test button.

Some van builders fit an interconnected pair — one in the living area, one near the electrical bay — so an early-stage wiring fire triggers the alarm before smoke reaches the sleeping area.

What to Do If an Electrical Fire Starts

Immediate Actions

1. Get out. This is the priority. A campervan fills with toxic smoke within 60 seconds of a fire starting. Do not try to save possessions — get yourself and anyone else out first.

2. Disconnect the battery if safe to do so. A main isolator switch accessible from outside the van (fitted to the leisure battery positive) lets you cut power without re-entering. This can prevent the fire from being sustained by continuing electrical current.

3. Use the fire extinguisher if the fire is small and you can do so without risk. A CO₂ extinguisher on a small wiring fire in the first 30 seconds can stop it before it spreads. If the fire has reached insulation, furniture, or gas fittings, do not fight it — get clear.

4. Call 999. Move well away from the vehicle — LPG cylinders can explode in a vehicle fire. Do not re-enter.

Prevention Is Everything

The actions above are last resorts. The goal is to build a system that never has a fire. A correctly fused, properly wired, well-maintained electrical system is not a fire risk — it is just a power source.

FAQ

How common are campervan electrical fires?

UK fire service data does not break out campervan/motorhome fires specifically, but vehicle fires from electrical faults are a significant category. Poor quality DIY wiring on converted vehicles is disproportionately represented. The risk is real but entirely preventable with correct installation.

Should I fit a battery isolation switch?

Yes. A main isolation switch on the leisure battery positive (accessible without tools, ideally from outside the van) lets you cut power quickly in any emergency. Costs £10-25. Some builders fit one on the vehicle battery too. It is also useful for long-term storage — cutting the battery prevents parasitic drain.

Does my campervan insurer require an electrical inspection?

Requirements vary by insurer. Many specialist campervan insurers require a documented electrical installation that meets relevant standards (BS 7671 or equivalent). An Electrical Installation Certificate from a qualified electrician costs £50-150 and satisfies most insurers' requirements. Check your policy wording.

Is a lithium battery more dangerous than AGM in a fire?

LiFePO4 chemistry is among the safest lithium chemistries — it does not catch fire or undergo thermal runaway as readily as other lithium types (LiPo, NCM). An LiFePO4 battery in a campervan fire is not the primary hazard. The greater risk is from insulation, plastics, and gas fittings in the van body. A properly managed LiFePO4 battery does not spontaneously catch fire.