Inverters In Campers: What You Need To Know

If you're wondering whether your camper has an inverter, it's important to first understand what an inverter is and what it does. In simple terms, an inverter converts the 12-volt DC power from your camper's battery into 120-volt AC power, which is the standard household electricity used to power appliances like microwaves, TVs, computers, and more. While some campers come equipped with an inverter, others may not have one installed. So, how can you tell if your camper has an inverter? One way is to check for specially marked wall outlets, as these indicate the presence of an inverter, allowing you to run certain appliances off the DC battery system while still providing AC power. Additionally, you can refer to your camper's manual or consult a professional to determine if your camper has an inverter installed.

What is an inverter?

An inverter is a device that changes direct current (DC) to alternating current (AC). DC flows in one direction, usually from a battery or solar panel, and is a constant flow at around 12V. AC changes direction, is usually around 120V, and is what you get from shore power or the electricity that runs through a house. Most rigs have two electrical systems: an AC system (similar to a typical home) and a DC system (similar to a car). The AC system can generate a lot more power than the DC system, which is limited by the RV batteries.

An inverter does the opposite of a converter. A converter changes an AC current to a DC current. When plugged into shore power, the converter takes the incoming 120V and reduces it to 12V for things like charging house batteries. A power inverter changes the 12V current from batteries or solar panels to 120V current for items that require it, such as residential refrigerators, TVs, and microwaves.

Inverters are available in a variety of sizes, including 1,000-watt, 3,000-watt, and 5,000-watt models. The size of the inverter depends on what you're running and how many things you need to run at once. A 1,500-watt inverter can usually handle a few things running simultaneously, but you may need an upgrade for more power.

There are two basic designs for producing household plug-in voltage from a lower-voltage DC source. The first uses a switching boost converter to produce a higher-voltage DC, then converts it to AC. The second method converts DC to AC at battery level and uses a line-frequency transformer to create the output voltage.

Inverters are also classified by their output waveforms, with the three common types being the square wave, the pure sine wave, and the modified sine wave. The square wave is simple and cheaper, but it has lower power quality. The modified square wave provides better power quality and is suitable for most electronic equipment. The true sine wave inverter has the best waveform and the lowest total harmonic distortion (THD) of about 3%. However, it is the most expensive.

What does an inverter do?

An inverter is a crucial electronic device that transforms direct current (DC) electricity into alternating current (AC) electricity. It is also known as a power converter, bridging the gap between different types of electrical currents. The main function of an inverter is to convert DC to AC, but it also has many other capabilities.

In simple terms, an inverter works by rapidly switching the polarity of a DC power source to create an AC output. This process involves converting the DC input into pulses, which are then shaped and smoothed to form a sine wave that mimics the AC power from the electrical grid.

Inverters are essential in renewable energy systems, such as solar and wind power installations. They convert the DC electricity produced by solar panels or wind turbines into AC power that can be used by homes and businesses. Inverters also synchronize this electricity with the grid, allowing excess energy to be fed back into the system.

Inverters are also commonly used in uninterruptible power supplies (UPS). They provide a backup power source during outages by swiftly switching to battery power and converting it to AC, keeping critical equipment running. For electric vehicles, including recreational vehicles (RVs), inverters manage power flow between the battery and motor, controlling speed and efficiency.

Inverters come in different sizes and capacities, from small units for portable electronics to large industrial-scale systems. They enable us to use DC power sources, such as solar panels or batteries, to power AC devices like computers, refrigerators, microwaves, TVs, and air conditioners.

In an RV, an inverter is particularly useful for running standard household appliances and electronics while on the road or camping off-grid. It allows you to use devices like laptops, TVs, and microwaves without needing to connect to shore power or running a generator.

Inverters offer enhanced energy efficiency and flexibility in power supply. They improve power quality by stabilizing voltage fluctuations and reducing harmonic distortions, making them valuable in industrial settings. Modern inverters also offer smart monitoring and control features, allowing remote management and optimization of energy consumption.

Why do I need an inverter?

If you're planning on living in your camper full-time, or even for a few weeks at a time, and want to use your household appliances without staying at campgrounds, you'll need an inverter. An inverter transforms the DC power stored in your camper's leisure batteries into AC power, which is what your household appliances need to run.

Most camper conversions, motorhomes, and RVs include a battery bank for charging 12v DC devices. But household appliances like laptops, TVs, and refrigerators need AC power, so an inverter is essential, especially when you're boondocking and not hooked up to a campground's shore power facility.

An inverter transforms DC power into AC power. Alternating current (AC) cannot be stored, but direct current (DC) can, and we use our camper's leisure batteries to store it. You can wire your DC appliances directly to the battery, and they'll run happily. But appliances that are usually plugged into a household power outlet need an AC power source.

The short answer is, you don't. You don't need an inverter if you can avoid running any AC appliances when off-grid. If your RV has a shore power electric hook-up facility, you can still run AC appliances when on a campground. But if you want to run even a small number of AC appliances on batteries alone, you'll need an inverter in your camper.

There are three different types of inverters: square wave inverters, modified sine wave inverters, and pure sine wave inverters. Square wave inverters are not generally available anymore, and modified sine wave inverters are cheaper but can be harder on electronics. Therefore, pure sine wave inverters are generally recommended for RV campers as they are more versatile and becoming more affordable.

The size of the inverter you need depends on the appliances you'll be running and how you'll be using them. The inverter needs to be powerful enough to run the AC components connected to it at any given time. You can reduce the size of the inverter you need by minimizing the number of appliances you have running simultaneously. You'll also need to consider the highest power draw of your appliances, as some appliances demand a power surge on startup. It's recommended to get an inverter rating of about 25% higher than the expected maximum load you intend to put on the system at any one time.

How do I choose the right inverter?

Choosing the right inverter for your camper is an important step in setting up your electrical system. Here are some factors to consider when making your decision:

Type of Inverter

There are two main types of inverters: pure sine wave inverters and modified sine wave inverters. Pure sine wave inverters are generally recommended as they provide a "cleaner" power output that won't damage your electronics. Modified sine wave inverters, on the other hand, can cause damage to certain devices and may not work with all electronics.

Size of Inverter

The size of the inverter you need depends on the power requirements of the devices you want to run. It's important to consider both the continuous power draw and the surge power requirements of your appliances. Calculate the total wattage of all the devices you plan to use simultaneously, including any start-up surges, and then choose an inverter that can handle slightly more power than that. For example, if your total power requirement is 1800 watts, you should round up and get a 2000-watt inverter.

Efficiency

Consider the efficiency of the inverter, as this will impact your battery life. Some inverters use more power just to be on, even when they're not powering any devices. Look for inverters with low idle power consumption, such as the Victron inverter, to maximize your battery capacity.

Features

Some inverters come with additional features that can be useful. For example, an inverter/charger combo can charge your batteries from a standard wall outlet, and some inverters have built-in transfer switches that allow you to easily switch between shore power and inverter power. Remote monitoring and troubleshooting capabilities are also available on certain models.

Cost

Larger inverters with more features will generally be more expensive. Additionally, the size of your inverter will impact the cost of other components in your electrical system, such as cable gauges, busbars, and switches. Keep in mind that a larger inverter will also require a bigger battery bank to support the higher power usage.

Safety

Always choose an inverter with built-in safety features to protect your devices and your camper. Look for inverters with overload protection that will cut off power if you accidentally exceed the maximum wattage. This will help prevent damage to your appliances and your inverter.

How do I install an inverter?

To install an inverter in your camper, you must first determine which type of inverter will meet your power needs. There are three basic types of units: pure sine wave inverters, modified sine wave inverters, and square wave inverters. Pure sine wave inverters provide "clean" and consistent power without surging and are ideal for powering sensitive devices with microprocessors, like laptops. Modified sine wave inverters, on the other hand, deliver "choppy" power with surges and are suitable for powering non-sensitive small appliances like lights, power tools, and fans. Square wave inverters are an older design that is not commonly used today.

When choosing the right inverter size, consider the difference between startup (peak) demand and running (continuous) demand. For example, an air conditioner requires a lot of power to start its compressor but less power to keep running. In contrast, coffee makers require the same amount of power for startup and running. As a rule of thumb, select an inverter with a rating of at least 15% higher than your maximum load.

There are two main ways to install an inverter in your camper: the simple installation method and the split distribution panel installation method. The simple installation method involves directly connecting the inverter to the 30/50 amp shore power connector via an extension cord. This approach is less expensive and requires fewer components. However, it entails manually connecting the inverter to the shore power outlet and manually turning off the converter when using the inverter.

The split distribution panel installation method, on the other hand, connects the inverter to the RV's electrical wiring AC distribution box through an automatic transfer switch relay. This method permanently connects the inverter to the RV's electrical system, eliminating the need for manual connections. It is more expensive and involves a more extensive installation process.

Step 1: Choose the Right Power Inverter

Select an inverter that suits your camper's power needs. Consider the type of devices you will be using and whether they require delicate electronics or not. Pure sine wave inverters tend to work better with sensitive devices. Additionally, check how much solar power your RV will need before installing the inverter.

Step 2: Find a Suitable Space in the Camper

Locate an ideal place to install the power inverter. It should be near your RV's battery charger but not in the same compartment. Ensure it is away from heat, liquids, and foot traffic, and in a place with adequate airflow. Many people opt for the cargo hold, but the choice depends on your camper's layout.

Step 3: Secure the Power Inverter

Use mounting hardware, such as screws or bolts, to secure the power inverter in place. If your inverter came with mounting hardware, use the included screws or bolts. Otherwise, measure the holes in the mounting frame and use appropriate fasteners.

Step 4: Wire the Power Inverter

Engage a licensed electrician to wire the power inverter to your camper's battery. Follow the recommendations in the power inverter's instruction manual. Typically, you will need to connect the inverter to the battery terminal using AWG cables, ensuring they are thick enough for better energy transfer.

Step 5: Ground Your Camper's Power Inverter

Follow the instructions in the user manual to ground the power inverter and safeguard your equipment. This usually involves connecting the ground wire to your RV's chassis.

Step 6: Test Your Setup

Once the installation is complete, take your camper off-grid and test your new power setup. If you encounter any issues, refer to troubleshooting guides or seek assistance from a professional.

Frequently asked questions