What Size Inverter Do I Need For My Campervan or Motorhome: A Technical Guide
In campervans and motorhomes, an inverter is essential for converting the 12 volts (V) DC power from your battery into 240V AC power for running household appliances.
This guide covers the critical factors in selecting the right size inverter you need, and includes a list of common 240V appliances and the inverter sizes required to power them efficiently.
This guide covers the critical factors in selecting the right size inverter you need, and includes a list of common 240V appliances and the inverter sizes required to power them efficiently.
Understanding the Basics: Inverter Types
There are three main types of inverters for campervans:
Pure Sine Wave Inverters: Ideal for sensitive electronics, the following appliances require a pure Sine Wave Inverter:
- Laptops and Computers. Modern computers and laptops with sensitive circuitry need a stable power source. Using modified sine wave inverters can cause overheating or damage to the internal components.
- Smartphones and Tablets. Charging these electronic devices with a pure sine wave inverter ensures optimal charging efficiency and protects the battery from potential harm.
- Televisions. Modern flat-screen TVs, especially LCD, LED, and OLED models, require clean AC power to function properly without flickering or noise interference.
- CPAP Machines. Continuous Positive Airway Pressure (CPAP) machines and other medical devices need a reliable power source to function safely, which is best provided by a pure sine wave inverter.
- Refrigerators and Freezers. Compressor-based appliances like refrigerators work more efficiently and with less wear and tear when powered by pure sine wave inverters.
- Microwaves. For even cooking and to avoid damage, microwaves need clean power.
- Blenders and Coffee Grinders. High-powered appliances with motors will run smoother and more efficiently with a pure sine wave inverter.
Modified Sine Wave Inverters: Suitable for non-sensitive appliances but may not work with all electronics.
Square Wave Inverters: Least suitable due to poor compatibility.
Table of Content
- Understanding the Basics: Inverter Types
- Inverter Power Requirements: Wattage Considerations
- List of 240V Appliances and Required Inverter Sizes
- Recommended Victron Phoenix Inverters
- Battery Compatibility and Considerations
- Battery Recommendations for Various Inverter Sizes
- The Best Inverters For Your Efficiency and Standby Consumption
- Size, Safety Features, and Installation of Inverters For Campervans
- What Size Inverter Do I Need: Summary
Inverter Power Requirements: Wattage Considerations
To determine the inverter size, you need to calculate the wattage of the appliances you plan to use. Inverters are rated by continuous power (for steady appliance operation) and surge power (for starting up appliances).
The inverter size you need depends on the total wattage of appliances you want to run simultaneously. For example, if you plan to run a laptop (100W) and a microwave (900W) at the same time, you’ll need an inverter with at least a 1000W continuous power rating to ensure smooth operation.
For appliances with high surge power demands (like microwaves or refrigerators), you need a larger inverter that can accommodate those initial spikes, which are usually 1.5 to 2 times the continuous wattage.
List of 240V Appliances and Required Inverter Sizes
Recommended Victron Phoenix Inverters
250VA: for small devices such as mobile phones, fans, and LED lights.
375VA: suitable for light kitchen appliances or small electronics.
500VA: great for moderate loads like laptops, TVs, or lighting.
800VA: sufficient for microwaves or small power tools.
1200VA: suitable for larger appliances such as coffee makers and electric kettles.
1600VA: For medium-load appliances like kitchen equipment or heating.
2000VA: powerful enough for heaters, power tools, and refrigerators.
3000VA: for heavy-duty devices like air conditioners & large power tools.
Battery Compatibility and Considerations
Ensure that the inverter matches your battery's voltage (typically 12V or 24V). Larger appliances or higher power consumption needs may require higher-capacity inverters and battery systems, such as 24V or even 48V setups.
Battery Recommendations for Various Inverter Sizes
- Power Consumption: Low (suitable for small devices like phone chargers and LED lights).
- Battery Recommendation: 12V 50Ah Lead-Acid or Lithium Battery.
- Explanation: A small 300W inverter draws about 25 amps at 12V (300W ÷ 12V = 25A). A 50Ah battery could theoretically run a 300W load for about 2 hours (depending on battery type and depth of discharge).
- Power Consumption: Moderate (suitable for running laptops, small TVs, or fans).
- Battery Recommendation: 12V 100Ah Lead-Acid or 12V 60Ah Lithium Battery.
- Explanation: A 600W inverter draws around 50 amps at 12V (600W ÷ 12V = 50A). A 100Ah lead-acid battery or a 60Ah lithium battery would run a 600W load for about 1.5 to 2 hours.
- Power Consumption: Higher (suitable for appliances like microwaves or larger TVs).
- Battery Recommendation: 12V 150Ah Lead-Acid or 12V 100Ah Lithium Battery.
- Explanation: A 1000W inverter draws approximately 83 amps at 12V. A 150Ah lead-acid or a 100Ah lithium battery would support a 1000W load for around 1 to 1.5 hours.
- Power Consumption: Significant (suitable for small kitchen appliances like blenders or coffee makers).
- Battery Recommendation: 12V 200Ah Lead-Acid or 12V 150Ah Lithium Battery
- Explanation: A 1500W inverter draws about 125 amps at 12V. A 200Ah lead-acid or 150Ah lithium battery would power this load for about 1 hour, depending on usage.
- Power Consumption: High (suitable for power tools, fridges, and electric kettles).
- Battery Recommendation: 12V 400Ah Lead-Acid or 12V 300Ah Lithium Battery.
- Explanation: A 2000W inverter draws roughly 166 amps at 12V. A 250Ah lead-acid or 200Ah lithium battery would support a 2000W load for around 1 hour.
- Power Consumption: Very high (suitable for air conditioners, large fridges, or multiple appliances).
- Battery Recommendation: 12V 400Ah Lead-Acid or 12V 300Ah Lithium Battery.
- Explanation: A 3000W inverter draws about 250 amps at 12V. A 400Ah lead-acid or 300Ah lithium battery would provide around 1 hour of run time.
Efficiency and Standby Consumption
Choose an inverter with a high efficiency rating (85-95%) to minimize energy loss during power conversion. Additionally, low standby consumption is essential to prevent unnecessary battery drain when the inverter is turned on but not actively powering any devices.
Size, Safety Features, and Installation
Pick an inverter that fits your campervan’s available space and has built-in safety features like overload protection, short circuit protection, and over-temperature shutdown. It’s important to install the inverter with proper ventilation to avoid overheating and extend its lifespan.
What Size Inverter Do I Need: Summary
Selecting the right inverter for your campervan or motorhome involves matching your 240V appliance usage with the appropriate inverter wattage. By calculating your power needs and understanding the demands of your appliances, you can choose a reliable inverter that provides a comfortable and functional off-grid experience. The recommended Victron Phoenix inverters offer robust performance across a wide range of power requirements, from basic electronics to heavy-duty appliances. Always opt for an inverter with a slightly higher power rating than you anticipate needing, to account for any unforeseen power surges or extra appliances.
Van Junkies: Our Story
Van Junkies started with a passion for conversion, initially with a Volkswagen Crafter and then a Mercedes Sprinter. Faced with the challenge of sourcing parts, we created Van Junkies to provide affordable solutions. Now based in Gosport, our warehouse caters to the growing demand for our products. Committed to customer satisfaction, we're here to assist you every step of the way. From off-grid solar design to complete conversion kits, we strive to be your ultimate destination for eco-friendly transformations. Specialising in Victron products, we ensure seamless integration and offer free support. Let's make your campervan, motorhome, or yacht a self-sufficient haven together.
