Pure sine wave vs modified sine wave campervan inverter. Which is best? feature image
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Pure Sine Wave vs Modified Sine Wave Campervan Inverters: Which Is Best?

Powering your gadgets and appliances on the road can be tricky. Choosing a suitable inverter for your campervan is crucial.

Campervan inverters: pure sine wave vs modified sine wave is often the debate many people have when building a campervan.

Each has advantages and disadvantages, affecting everything from efficiency and cost to the types of appliances and devices you can power.

Whether planning a weekend getaway or a long-term journey, understanding the differences between these inverters will help you make an informed decision for a smooth and enjoyable experience.

Portrait photograph of Jolly sipping a coffee

Trust Me, I’m An Electrician

Jolly (a self-confessed electrical geek with over 17 years of experience as a qualified electrical engineer) carried out the product review and testing.

His focus now is campervan conversion electrics which started in 2019 with the birth of Vandercamp. Jolly is either building his own campervan or providing electrical help and guidance to others.

The Renogy 2000w Inverter Charger is installed on his current campervan powered from a Renogy 200Ah Lithium Leisure battery and 600w solar system.

Disclaimer

The information in this post is a combination of our knowledge, expertise and research. The content of the post is not sponsored. Therefore, all opinions are our own.

This post may contain affiliate links. Meaning, if you make a purchase after clicking one, we may earn some commission. This pocket money will help Vandercamp Adventures continue to grow at no extra cost to you. It’s a win win situation!! Learn More…

Overview

Pure Sine Wave Inverters

Renogy 2000W Pure Sine Wave Inverter

Consider investing in a pure sine wave inverter if your budget allows, as it ensures that all of your appliances, gadgets, and electronic equipment can be powered efficiently and safely.

Modified Sine Wave Inverters

1000W Modified Sine Wave Inverter

If you’re on a budget and need basic power for lights, water pumps, or charging devices, a Modified Sine Wave Inverter should suffice. They’re ideal for camping or in-car charging. An MSW inverter should work fine for 90% of users and most appliances.

What Is an Inverter?

An inverter is a handy piece of electrical equipment that turns 12v DC power into 230v AC power. This 12v DC power comes from a leisure battery or solar system in your campervan. On the flip side, 230v AC power is the type of electricity you’ll find in your home.

You’ll need an inverter to use home appliances with a 3-pin plug or any electronic gear that can’t run on battery DC power. When camping in your campervan, you can plug a portable inverter into the cigarette lighter to get power through a 3-pin plug, or you can go big and hard-wire larger units directly into the electrical system.

There are two types of campervan inverters: pure sine wave and modified sine wave. Both types produce a 230-volt output to power your appliances, but they differ in the way the electricity is delivered. These differences are explained below.

How Does a Campervan Inverter Work?

An inverter specifically takes the 12v DC from your leisure battery or solar system and turns it into 230v AC power. This 230v AC output is precisely what you need to run your home gadgets.

Inverters are made of sophisticated components in order to convert DC power to AC Power. Luckily, we don’t need to delve any deeper into these components in this post.

However, what is DC and AC power?

DC Power (Input Power)

DC power stands for direct current. This current comes from electrical sources like batteries, solar panels, and alternators.

The electrical charge in DC power flows in just one direction, creating a linear and straight-line current. This results in a smooth flow and even voltage throughout the system. 

If you’ve ever wondered, you can convert AC to DC using a rectifier, commonly found in phone and laptop charger plugs.

AC Power (Output Power)

AC power stands for alternating current. It’s the type of electricity a power grid generates that is then supplied to your home.

Unlike DC power, the electrical charge changes direction periodically. In simple terms, this means the flow of electrons moves in an oscillating motion: upwards (positive) or downwards (negative).

This change in direction happens at a specific frequency: for example, 50Hz in the UK and Europe and 60Hz in the USA.

 Frequency

Frequency is the term used to describe how quickly AC current oscillates (changes direction) every second. It’s measured in hertz (Hz), where 1 hertz equals 1 cycle per second. 

When shopping for a power inverter, you’ll encounter different frequencies depending on what country you are in. It’s crucial to choose one that aligns with your country’s frequency; otherwise, you could end up with issues with performance. 

See what frequency your country uses in this table.

What Is a Pure Sine Wave Campervan Inverter?

Also known as PSW or true sine wave, this type of inverter is the gold standard for replicating the power in your home. It operates on an oscillation waveform, which is the cleanest and best type of sine wave you can get from an inverter. 

Pure or true sine wave shown as a smooth consistent curve with immediate change in direction at 0 volts.

The voltage in a pure sine wave inverter rises and falls smoothly, tracing a consistent curve. This is the same kind of power that comes from the outlets in your house. With this type of voltage, it allows your electronic devices to run in a smooth, clean, and efficient manner. 

One of its standout features is its ability to change frequency immediately as the wave crosses 0 volts, resulting in a clean and consistent power supply.

What Can I Power With A Pure Sine Wave Inverter?

With a Pure Sine Wave Inverter, the range of devices you can power is impressively broad. From everyday household appliances like digital microwaves, newer televisions, and fridges to laptops and other electronic equipment, everything runs smoothly. It’s also ideal for appliances with AC motors, electronic timers, or digital clocks. 

Digitable nomads working on an extendable camper table
Laptops powered from our 2000W Renogy Pure Sine Wave Inverter Charger

If you have variable-speed motors in devices such as fans, blenders, or drills, they’ll operate without any glitches. 

Music enthusiasts will be pleased to know that audio devices are compatible, while light dimmers and battery chargers also benefit from a PSW inverter consistent power supply. 

A Pure Sine Wave Inverter provides a reliable power source for all household and electronic items.

What Is a Modified Sine Wave Campervan Inverter?

Also known as MSW or quasi-sine, the Modified Sine Wave inverter is a more budget-friendly option. Typically, 20-40% cheaper than its pure sine wave counterparts. 

It can power most electronic devices, but it does have some quirks. The voltage in a modified sine wave rises and falls abruptly, resembling a ‘square’ or ‘staircase’ pattern, switching suddenly from positive to negative polarity. Therefore, the waveform has long pauses at 0 volts, making it noisy and rough around the edges. 

Modified or quasi wave form shown as a stair pattern rising and falling abruptly with long pauses at 0 volts.

While most gadgets will work just fine, some electronic devices may struggle‌ with overheating or getting damaged. Motors, for example, can consume up to 30% more power than they would with a pure sine wave inverter. This increase in power consumption can lead to excess heat and a shorter lifespan

You might also notice some equipment, like radios, producing a buzzing sound when in operation. So, while a modified sine wave inverter is generally more affordable, it’s worth considering these factors to ensure it meets your needs.

What Can I Power With A Modified Sine Wave Inverter?

When using MSW inverters, it’s important to understand their limitations and the type of appliances they can power. While most appliances will run on MSW inverters, not all will operate optimally.

In fact, roughly 80% of appliances will function well, 10% won’t work at all, and the remaining 10% may fail immediately or over time.

For your convenience, here’s a list of appliances that can be powered by MSW inverters:

  • Water pump
  • Electric kettle
  • Water heater
  • 3-way fridge (no digital controls)
  • Toaster
  • Small desktop fan

Refer to the comparison table below for more information.

MSW inverters are best suited for powering older technology and resistive loads, such as heating elements in water heaters and small fans like computer and desktop fans. However, bear in mind that heating elements may not operate at full efficiency with MSW inverters.

What Can’t I Power with A Modified Sine Wave Inverter?

While a Modified Sine Wave (MSW) Inverter can be useful for specific applications, it has its limitations. Although approximately 90% of appliances and electrical equipment can work with an MSW inverter, not all of them function seamlessly.

MSW inverters have different components and specifications, so providing an exact list of what won’t work with ALL MSW inverters is misleading. Thus, we have compiled a list of appliances and electrical devices that may work with an MSW inverter but may not function as expected.

Here are some examples:

  • Laptop/Phone Chargers: The charger plug may get hot and buzz and shorten the battery life.
  • Fluorescent Lights: They may hum and buzz, appear dimmer, or not work at all.
  • Household Refrigerators: They may cause excess heat. Put excess stress on the compressor and affect the internal electronics.
  • Battery Chargers (for toothbrushes, drills, cameras, etc.): They may cause excess heat in the charger and battery, which could shorten the battery life.
  • Electronic Timers & Digital Clocks: They may either not run at all or run out of sync.
  • Variable Speed Devices (such as fans or drills): They may only function in an on-or-off manner, lacking any speed control.
  • Lighting Dimmers: They may flicker or fail to dim.

Refer to the comparison table below for more information

While Modified Sine Wave Inverters are an affordable option, it’s crucial to be aware of their limitations when deciding what to power with them.

PSW vs MSW: What Can I Power?

Appliance/Electronic EquipmentPure Sine WaveModified Sine Wave
Water Heater
Water Pump
Electric Kettle
Toaster
Small fan (Computer, desktop)
3-Way Fridge (no digital controls)
Laptop/Phone ChargersCharger plug may get hot, buzz and shorten the battery life.
Fluorescent LightsMay hum and buzz, appear dimmer, or not work at all.
Battery Chargers (toothbrush, drill, camera etc.)May cause excess heat in the charger and battery, shortening its life.
Electronic timersNot run at all or run out of sync.
Digital ClocksNot run at all or run out of sync.
Variable Speed Devices (fans and drills)May only function in an on-or-off manner, lacking any speed control.
Lighting DimmersFlickering and failure to dim.

PSW vs MSW: Advantages And Disadvantages

PSW Advantages

  • Good heat dissipation – Does not cause excessive heat build-up.
  •   Does not add stress to electronic devices.
  •   Efficient power conversion of 90-95%
  •   Appliances will work efficiently and as they’re designed to.
  •   Electronic devices produce less audible noise/interference.

MSW Advantages

  •   2-4x less expensive than PSW inverters.
  •   Perfect for small campervan electrical use.
  •   They’re better suited to small leisure batteries.
  •   More economical than PSW inverters.

PSW Disadvantages

  • 2-4x more expensive than MSW.
  •   Use more battery power due to complicated electronics.
  •   Typically weigh more than MSW inverters.

MSW Disadvantages

  • Can create electronic noise on certain appliances.
  • Cause motors to run hotter and less efficient.
  • Not compatible with some electronic devices, as the device won’t work.
  • May shorten the life of laptop and phone batteries.
  • Less efficient power, with only 75-85% efficiency, compared to 90-95% efficiency with PSW inverters.

Efficiency

With campervan inverters, efficiency is a key factor to consider. Efficiency is quantified as a percentage to give you a clear idea of how well the inverter performs.

Pure sine wave inverters are generally more efficient, operating at around 90-95% efficiency. On the other hand, modified sine wave inverters lag a bit, with an efficiency range of 75-85%

For example, a 2000w inverter with 90% efficiency will‌ need 10% more power to deliver the full 2000w. Therefore, 2200w of power is required to deliver 2000w from the inverter.

The process of converting DC to AC power isn’t without its costs. During this conversion, some of the power is lost in the form of heat.

NOTE: It’s worth noting that efficiency can drop when the inverter is supplying high-current loads close to its maximum output. This could reduce the inverter’s efficiency by more than 5%. Therefore, to maintain better efficiency, it’s advisable to choose an inverter that’s 20-25% larger than your total maximum load. This ensures you get the most out of your inverter while keeping it running efficiently.

For example, if your maximum load equals 1500 watts, a 1800 watt (or larger) inverter is advisable.

So, Do I Need A PSW Inverter?

Are you wondering if you need a Pure Sine Wave (PSW) Inverter? Well, it all comes down to your budget and what you need to power

If your budget allows, then a PSW inverter is a sure winner. However, if your budget is more limited and you have gadgets like phone chargers or basic electronics, a cheaper ‘good quality’ modified sine wave inverter should do the job. But it may not be perfect; some devices could be noisy or not work as well as they could.

However, if you’ve got stuff like fridges, computers, or fancy lights, you’ll want a PSW Inverter. It’s also better for things with speed controls like fans or “smart” devices like a high-tech toothbrush.

A PSW Inverter is your best option if your gadget is more complex or sensitive.

So, while you can get by with a good quality MSW inverter for some things, a PSW Inverter is often a better choice for keeping everything running smoothly.

Further Reading | The Best PSW Campervan Inverters

Verdict: Which One Should You Buy?

Here’s an overview table to help you decide:

Pure Sine WaveModified Sine Wave
Cost- 2-4x more expensive than MSW due to higher manufacturing costs.- 2-4x less expensive than PSW. Easier to produce and has less components.
Efficiency- 90-95% efficient.
- Can use more power in standby mode due to sophisticated electronics.
- 75-85% efficient
- More economical in standby mode.
- Motors can use 30% more energy.
Interference- Electronic devices produce no audible noise/interference.- May create audible noise/intererence on some electronic devices. Such as digital clocks, audible devices and light bulbs.
Usage- All home appliances.
- All electronic equipment
- Not suitable for sensitive electronic equipment.
- Some devices may not work or become damaged.
Power usage- Minimal power loss due to the smooth and clean AC waveform.
- Similar to the power that's found in your home.
- The AC waveform is rough, creating less efficient power.
- More power is required to work at full capacity, causing excess heat build up in the inverter and appliance.

Best suited to- Suitable for all users, appliances and electronic devices.
- Higher budgets.
- Electrical system powering household items, gadgets and sensitive electronic equipment.
- Larger capacity leisure batteries.
- Suitable for 90% of users and most appliances.
- Lower budgets.
- Small capacity leisure battery's.
- Basic power needs, like lights, water pumps, or‌ just a phone and laptop charger.

Buy A Pure Sine Wave Inverter

If you have more room in your budget and you’re looking to power household appliances or need reliable power for work on the go, a Pure Sine Wave (PSW) Inverter is your best bet

Especially if you have a more complex electrical system powering household items, gadgets and sensitive electronic equipment.

Plus, you’ll have the added peace of mind of knowing that whatever you plug in will run efficiently and safely.

Need help finding the best PSW inverter? Here’s a comparison post of the Top 5 PSW Campervan Inverters for 2024.

Buy A Modified Sine Wave Inverter

If you’re working with a tighter budget and your power needs are more basic, like lights, water pumps, or‌ just a phone and laptop charger, then a Modified Sine Wave (MSW) Inverter should suffice. 

These inverters are ideal for less demanding camping trips or in-car charging.

For the average user, an MSW Inverter will work well in about 90% of cases if used for the right applications. Most of your appliances should operate without any noticeable difference. 

The Best Campervan Pure Sine Wave Inverter

RENOGY 2000 Watt Inverter

Also available as 1000W and 3000W

The Renogy Inverter has been voted as one of the 5 best PSW inverters for campers 2024 by Vandercamp Adventures.

The Best Campervan Modified Sine Wave Inverter

Sunshine Solar 1000 Watt Inverter

Available from 150W to 3000W

FAQ’s

Is A PSW Inverter Worth The Extra Cost?

Not only does a pure sine wave inverter provide high-quality power supply for your electronic devices, but it also protects them from voltage peaks and electrical noise.

In conclusion, it is a worthwhile investment.

Explore the advantages and disadvantages and why you should invest in a PSW inverter?

Can An Inverter Be Used With Solar?

To power a campervan inverter, it’s important to have a regulated input DC voltage.

This means that the DC output of the solar system should be constant and can be achieved using an MPPT solar charge controller.

This device ensures that the voltage remains at 12 or 24 volts, which is the required input for most campervan inverters.

What Size Inverter Can I Run Off A 100Ah Battery?

The size of the inverter will depend on many factors:

  • Total power usage and load required from the inverter.
  • Battery type
  • Maximum daily power demand
  • Battery recharge time

This post delves deeper into what size inverter is required for a 100Ah battery.

What PSW Inverter Should I Buy?

In our opinion, when it comes to brands for campervan electrics, two stand out from the rest: RENOGY and Victron.

Renogy’s inverters are budget-friendly and user-friendly, offering three models ranging from 1000-3000 watts. Check out the Renogy Inverters to see if they meet your needs.

Victron, on the other hand, is arguably the biggest brand in campervan electrics. They offer a wide range of inverters that can cater to your specific needs, but they come at a higher price tag. Check out the Victron Inverter range to see if they have what you need.

Further Reading | Top 5 PSW Campervan Inverters For 2024 | A Comparison Guide

Recap

In summary, choosing a pure sine wave vs modified sine wave inverter for your campervan rests with you. Your budget, the types of devices you’ll power, and how you plan to use them are all key factors.

If your budget allows and you’re looking for the most efficient and reliable option, especially for sensitive electronics, a pure sine wave inverter is the way to go. However, a modified sine wave inverter can still serve you well if you’re on a tighter budget and your needs are more basic.

Both options have their pros and cons, but understanding these can help you make an informed choice that best suits your specific needs, guaranteeing a smooth and enjoyable journey.

Now you know which type of inverter you need, It’s time to choose an inverter for your campervan by following this ULTIMATE GUIDE. Alternatively, jump right into discovering the best inverters for campervans of 2024.

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