Australia Caravan & RV Power Guide

Caravan Generator Sizing Guide: How to Power Your RV & Air Conditioner

Generators are essential for off-grid camping across Australia. However, choosing the right inverter generator for your caravan or motorhome requires understanding wattage requirements, startup inrush currents, and Australian ambient temperature de-rating factors.

⚡ Typical Caravan Appliances & Power Requirements

Estimate your continuous power draw before selecting a portable inverter generator for off-grid Australian travel.

Caravan Appliance / Equipment
Typical Running Power (Watts)
💡 Evening LED & Canopy Lighting
150 W
🔋 Caravan Battery Charger (12V System)
100 - 200 W
📺 Smart TV & Entertainment System
150 - 300 W
📻 Audio & Portable Radio Equipment
50 W
🚿 Electrical Hot Water Service
500 W
❄️ Caravan Air Conditioner (Houghton / Roof Unit)
1,000 - 1,600 W
🌀 Portable Fan / Air Circulator
50 W
🧊 Caravan Refrigerator (150L 3-Way / Compressor)
80 W
🔥 Electrical Resistance Space Heater
1,000 - 1,500 W
🛌 Electric Blanket
150 W
🍿 Compact Microwave Oven
900 W
Standard Load

1. Resistive Electrical Loads

Resistive loads include appliances like incandescent lights, water heaters, space heaters, and electric blankets.

These draw constant power, making them easy to calculate against an inverter generator’s continuous output rating. For example, a generator rated for 1600W continuous output can comfortably run a 1500W heater.

Sample Load Calculation:

  • Caravan Lighting 150 W
  • Hot Water Unit 500 W
  • Electric Air Heater 1500 W
  • Electric Blanket 150 W
  • Total Continuous Power Needed 2300 W

📌 You will need a portable generator rated at a minimum continuous 2300 Watts.

Motor Loads

2. Inductive Electrical Loads (Air Conditioners)

Inductive loads contain electric motors and compressors (such as caravan air conditioners, fridges, and power tools).

3x - 4x Inrush Surge Current: Electric compressor motors require up to 3 to 4 times their normal running power during initial startup.

While small electronics (TVs, fridges) demand minimal surge capacity, running a 1300W RV Air Conditioner requires substantial peak surge power from your generator to start the compressor seamlessly.

Understanding Inverter Generator Ratings & Australian Climate Impact

Modern pure sine wave inverter generators are lighter, quieter, and far better equipped at starting motor-driven inductive loads than legacy conventional generators.

⚠️ Maximum vs. Continuous Wattage Rating: Always verify the Continuous Output Rating. Advertised peak figures represent short-term surge power, whereas continuous power determines what your generator can sustain long-term.

A caravan air conditioner consuming 1300W while running may need a momentary spike of up to 4000 Watts to overcome compressor inertia during startup.

🌡️ Australian Heat & Engine De-rating

Generators rely on internal combustion engines. In high ambient Outback temperatures, engine air density drops, lowering power output.

Rule of Thumb: Deduct 1.5% power output for every 5°C increase above 25°C.

Example: At 45°C ambient temperature, a 1500W generator experiences a 6% power reduction, delivering only ~1410W continuous output.

☀️ The Summer Air Conditioning Paradox

Air conditioners are factory tested at 35°C. As ambient temperatures rise to 40°C+, compressor load increases, causing the unit to draw significantly more power (e.g., 1400W+).

The Extreme Heat Challenge: As your air conditioner demands MORE power in heat, your generator produces LESS.

The Final Verdict for Australian Caravan Owners

High-quality inverter generators are capable of powering modern caravan air conditioning systems like Houghton Air Conditioners. However, in scorching Australian summer conditions, power margins become tight.

When sizing your generator, ensure you factor in ambient heat loss, appliance surge wattage, and simultaneous power consumption for reliable off-grid performance.

Consult Karma Air For Compatibility Advice