What Size Generator Do You Need for a Campervan?

Generator sizing for a campervan comes down to what you plan to run from it. Most van lifers need far less than they think — a 1,000W unit handles battery charging; a 2,000W unit handles almost everything.

How to calculate what size you need

Add up the wattage of everything you plan to run from the generator simultaneously. This is your minimum required generator output.

Common loads:

Example: battery charging only

• 25A Victron Blue Smart charger: 380W
• Generator needed: 500W minimum → a 1,000W generator with comfortable headroom

Example: battery charging + kettle

• 25A charger (380W) + 750W kettle = 1,130W
• Run charger and kettle simultaneously → 2,000W generator

Example: battery charging + power tools

• 25A charger (380W) + 900W angle grinder = 1,280W (plus startup surge ~2,500W)
• Generator needed: 2,000W+ with high surge capacity

Generator size options

Under 1,000W (e.g., Honda EU10i, 1,000W)

• Weight: ~8–10kg — most portable
• Noise: Very quiet (47–52 dB)
• Can run: Battery charger (20–25A), laptop, lights
• Cannot run: Kettle, large power tools, most 230V appliances
• Best for: Battery charging only, ultralight setup

1,000–2,000W (e.g., Yamaha EF1000iS, 1,000W; WEN 1,600W)

• Weight: 12–16kg
• Can run: Battery charger + small appliances
• Suitable for most campervan charging needs without running high-wattage appliances simultaneously

2,000W (e.g., Honda EU22i, Hyundai HY2000Si)

• Weight: 19–22kg
• Can run: Battery charger + kettle + laptop, or power tools, or portable AC unit
• This is the most popular size for campervans — handles almost any realistic need
• Best all-round choice for most van lifers

Over 2,000W (e.g., 3,000–5,000W generators)

• Weight: 30–60kg — not practical for most van setups
• Required for: Large portable AC units + heavy power tools simultaneously
• Too large for most campervans

Inverter generator vs conventional generator

For campervans, always choose an inverter generator. Reasons:

1. Pure sine wave output — safe for all electronics, laptops, battery chargers
2. Variable engine speed — quieter and more fuel-efficient under light loads
3. Lower weight — same output, lighter chassis than conventional generators
4. Lower noise — critical for campsite use

Conventional generators produce modified-wave or unfiltered output with frequency variation. Avoid these for campervan use.

Model comparison at 2,000W

Honda and Yamaha are the most reliable and quietest — worth the premium if you will use the generator regularly.

Hyundai and WEN offer good value for occasional use.

The 1,000W case: smaller is often enough

Most campervan battery charging does not require a 2,000W generator. A Honda EU10i (1,000W, 8kg) runs:

• A 20A mains charger (draws ~300W) — charging 100Ah LiFePO4 from 20% to full in ~4 hours
• Laptop and phone simultaneously
• Total load: ~400W from a 1,000W generator — very comfortable

If battery charging is the primary use case and you will not run a kettle or power tools simultaneously, save £200 and 12kg with a 1,000W model.

FAQ

Can I parallel two generators for more power?

Some inverter generators (Honda, Yamaha) have a parallel kit that allows two identical units to run together, doubling output. This is rarely needed for campervans — a single 2,000W unit is usually sufficient.

What fuel do campervan generators use?

Most portable generators run on standard unleaded petrol (E5 or E10). Some models also run on LPG. Petrol generators need to use fresh fuel — petrol degrades over 30 days and can gum up carburettors. Use a fuel stabiliser if storing fuel.

Can I run my generator and solar MPPT at the same time?

Yes — connect the generator to your 230V mains charger, which charges the battery. Your solar MPPT also charges the battery. Both sources can run simultaneously without conflict as both regulate their output voltage.