What You Need to Know About Inverters
Choosing the right inverter is one of the most important decisions for your caravan, motorhome, or off-grid setup.
The wrong choice can lead to power loss, appliance damage, and higher long-term costs. In this guide, we break down what you need to know about inverters — so you can confidently choose the right setup based on your actual power needs. Explore our inverter solutions →
Quick Sizing Example Table
| Appliance Type | Power Rating (Watts) | Running Status |
|---|---|---|
| TV | 100W | Running simultaneously |
| Laptop | 100W | Running simultaneously |
| Charger | 20W | Running simultaneously |
| Total Minimum Required | 220W | Base concurrent load |
| With 20% Safety Margin | 264W | Suitable for a 300W Inverter |
Below is a detailed breakdown to help you make the right decision based on your setup.
Looking for the right power conversion? View Pure Sine Wave Inverters or Explore Inverter Charger Options.
Quick Answer
Pure Sine Wave Inverters → Best for sensitive electronics, laptops, and modern household appliances
Modified Sine Wave Inverters → Only suitable for basic tools or light bulbs, not recommended for complex electronics
What are inverters?
Inverter is the device that converts 12V DC power to 240V AC. They are available in different types and different sizes.
Why do we need inverters?
In a standard caravan/RV/any other recreational vehicle, the power supply is normally one or a group of 12V batteries. The power supplied by 12V batteries would be 12V DC.
The appliances that we plug in to the wall socket at home need 240V AC, as supplied by the grid. So if you would like to bring some of these appliances into your recreational vehicle, an inverter is needed to convert 12V DC from batteries to 240V AC to power them.
Here are some examples of 240V AC appliances that Australians like to use on their recreational vehicles:
- TV and microwave
- Hair dryer and laptop
- Chargers for cameras, phones, and tablets
Many of these appliances do have models available on the market that can accept 12V DC power source, they are called 12V TV, 12V microwave, 12V hair dryer and even 12V coffee machines. But still many Australians prefer to use the ones that they use at home, and it’s quite a large expense to purchase every appliance you need in 12V, so an inverter is still considered an essential device in recreational vehicle’s electrics.
What is the efficiency of inverters?
Inverter efficiency is usually in the range of 85 to 95%. Mostly in the 90%, so the efficiency is quite high.
If one of your 240V appliances is drawing too much power, it’s usually because the 240V appliance itself consumes too much power, not because of energy loss in the inverter. Energy supply in a recreational vehicle is scarce and most 240V appliances are not designed to be extremely energy efficient. The 12V versions, on the other side, are normally designed with low energy consumption as a priority.
What types of inverters are there?
Two main types are available on the market:
- Pure Sine Wave Inverters: Replicates the exact characteristics of grid electricity.
- Modified Sine Wave Inverters: Does not replicate grid electricity characteristics, leading to choppy power waves.
Summary: pure sine wave is better than modified sine wave as it replicates the characteristics of the electricity supplied by grid and modified sine wave doesn’t. Complex electronics have to run off a pure sine wave inverter. If you are only powering light bulb or power tool you may get away with modified sine wave but for TV, laptop, a pure sine wave inverter is definitely needed.
What size inverter should I get?
This all depends on your actual usage. Simply calculate the minimum requirement by adding the power of the appliances that will be running at the same time together and add another 20% safety margin.
Sizing Breakdown:
- For small setups: Let’s say we have a 100W TV, a 100W laptop, and a 20W charger and they will possibly be running at the same time. We will have 220W x 120% = 264W. So a 264W inverter would be suitable (will end up with a 300W inverter of course). If you only run laptop, phone and camera chargers off it, the chance is 300W should be enough.
- For heavy-duty setups: But if you need to run hair dryer and microwave, please find out the power rating and calculate accordingly. Normally an inverter that is more than 1500W is needed.
⚠️ Always buy inverters that are certified by Australian safety standards.
For a complete system overview, see our Off-Grid Power System Design Guide.
Need Help Choosing the Right Inverter?
Not sure what size inverter fits your appliance setup?
Our team can help you design the right pure sine wave inverter solution based on your power needs and application.
Frequently Asked Questions (FAQ)
Q: Is pure sine wave always better than modified sine wave?
A: Yes — complex electronics, laptops, and TVs must run on pure sine wave to prevent damage.
Q: What happens if I choose an inverter that is too small?
A: The inverter will trip or shut down when the combined power of running appliances exceeds its limit.
Q: Will a 300W inverter run a microwave?
A: No — a microwave typically requires a heavy-duty inverter that is more than 1500W.
Q: Can an inverter be connected to any 12V battery?
A: Yes, but ensure your battery bank capacity can handle the continuous high current draw of the inverter.