How Does Your RV Electrical System Work? A Guide to RV Power

Despite being so important, RV electrical systems can be an overwhelming topic to dive into.

Where do you start??

There’s:

• Amps
• Volts
• Watts
• Generators
• Batteries
• Inverters
• Solar
• AC power
• DC power

… sorry, not helping.

Not to worry. If you’re new to electrical systems, particularly RV electrical setups, this guide will take you through everything in a logical fashion so that you can learn how it all works.

In the end, you should be much better equipped to start handling your own electrical setup and power needs all on your own.

No guarantees– if you’re new to this, it’s often best to hand it to a professional. However, when you’re on the road you don’t always have that choice and it can be a lifesaver to know your way around the electrical aspects of your rig.

So, let’s start from the top:

How RV Electricity Works

There are four aspects to how electricity is measured, referred to by the terms:

• Amps: Measures the speed at which electricity passes through something.
• Volts: Measure voltage, the force that drives electricity.
• Ohms: Measures resistance and electrical efficiency.
• And Watts: Measures the amount of electrical energy, the basic metric of power.

You can use two of any of watts, amps, or volts to calculate the third as seen in these equations:

• Volts = Watts / Amps
• Amps = Watts / Volts
• Watts = Amps x Volts

None of these are essential to know to set up your electrical system and fully power your RV life. 

However, they’re useful to start familiarizing yourself with as you make your electrical system more and more complex.

“Amp hours” are an important term to know in the case of RV batteries that you’re likely to encounter.

Amp hours are a unit of measurement that gauges a battery’s capacity, a combination of the amount of time a battery requires to fully discharge with the amount of current. 

However, the term can be a bit confusing. “Amp hours” refers more to an amount of energy rather than an amount of time.

For example, 100 amp hours will last 10 hours if you’re drawing 10 amps per hour (10×10). However, if you’re pulling just 5 amps per hour, your 100 amps of power will last 20 hours. 

Types of RV Power: AC vs. DC Power

One of the most important things to know about how RV power works is the difference between DC and AC power.

Your RV can use two different types of electricity: 12-volt DC and 120-volt AC.

Batteries store energy in the form of 12-volt DC or “direct current” power. 

Some devices and appliances can use DC power. However, many– especially larger appliances such as fridges and AC– require 120-volt AC or “alternating current” power.

You can get by with DC power– especially if you stay at RV parks often where you can usually get 120-volt AC electrical hookups– but you’ll be a bit limited in terms of what you can power otherwise.

If you want to ensure you can power everything in your RV no matter where you are, you’ll want to get an inverter, which can convert DC power into AC. 

Another option is getting an inverter generator, which will similarly convert DC power to AC (more on that in a bit).

Ideally, you have both for total flexibility and a backup no matter where you are and no matter what happens.

RV Power Sources: 4 Factors

Now, let’s talk about the different types of RV power sources (or key tools in converting and utilizing power).

The main tools are:

• Batteries
• Inverters
• Generators
• And solar power

Batteries

RV batteries are lead-acid-based and used for storing power. It’s common to see RVs have more than one battery.

They’re particularly useful when you can’t plug into shore power or you rather not run your generator.

They’re also used for storing the power you draw using solar panels, making them a key power bank especially if you have panels on your RV’s roof that are constantly drawing energy.

Inverters

Inverters are a type of power converter that allows you to take DC power and convert it into the 120-volt AC power you need to power many appliances. Including:

• Fridges
• Microwaves
• And AC

With an inverter, you’re not limited in terms of what you can power.

You can also use an inverter generator to produce AC power, which has become increasingly more popular in recent years.

Learn more about inverters:

• What Does an Inverter Do In an RV? + Types of Inverters, How to Install, and More
• 3 Best Inverters for RVing: 2024 Buyer’s Guide

Generators

Generators use fuel to produce energy and they’re a great accessory in addition to your primary power sources.

They can be used any time you don’t have access to shore power to power your various devices, even your appliances and smaller devices in the case of an inverter generator.

Standard and inverter generators are somewhat different from one another. The differences can be summed up as:

• Inverter generator: Cleaner and more efficient power source. Much quieter than traditional generators, but more expensive.
• Standard generator: More powerful when comparing apples-to-apples but less efficient power. Very loud to the point of being annoying but more affordable than inverter generators.

To summarize things, noise and accessibility are the primary reasons to choose an inverter generator.

Conversely, standard generators are a great starting point being more affordable and offering more power. 

Learn more about generators:

• 7 Best Portable Generators for RV’s and Camping [2024 Guide]
• 6 Pros and Cons of Inverter Generators for RVing
• 4 Best Inverter Generators for RVing: 2024 Buyer’s Guide

Solar

Finally, solar power is another useful tool when it comes to RV power.

Solar panels allow you to draw power from the sun’s rays, which when combined with a battery to be stored can provide an almost unlimited supply of energy.

There are limitations, however. When the weather isn’t optimal, you draw less energy which makes energy production inconsistent.

Solar power certainly can’t be your only source of energy. However, it’s an amazing secondary form of energy that is low cost and can be generated passively as you go about your day.

Learn more about solar panels here: How Much Solar Power Do You Need to Run an RV Fridge?.

And find our top picks for the best portable solar panels for RVing.

Practice Proper RV Electrical Maintenance

It’s vital to practice proper inspections and maintenance throughout your RV’s electrical system.

With frequent inspections, you’ll be more likely to catch issues before they become a real problem.

A few tips include:

• Inspect your RV electrical panels if and when something isn’t working properly
• Check the connections on your batteries for damage and corrosion
• Check your battery’s electrolyte levels and add water when low (unless you’re using lithium batteries, in which case no need)

It’s also important to have a professional occasionally take a look at your electrical system to make sure everything is working fine.

There are things you may not notice unless you’re a trained electrical engineer, which a professional inspection every year or few years can catch.

4 RV Electrical Tips

Your RV’s electrical system is complex but many common issues have simple fixes.

To that end, below are a few tips for helping manage your electrical system. 

However, if you’re ever unsure of what you’re doing and you feel out of your depth, prioritize safety and have a professional take a look.

With that said, here are some tips for getting the most from your RV’s electrical setup:

1. Electrical issues? Check your circuit breaker

In many cases, if something goes wrong power-wise, the issue will be in your circuit breaker.

When you’re having electrical issues, open up your circuit breaker first and inspect it. You may have tripped one of the breakers, in which case you can simply flip it back on and you’re good to go.

2. Unplug before any electrical work (or hire a professional)

Before you even think of doing any sort of electrical work on your RV, it’s vital that you unplug and turn off all devices, appliances, and the source of electricity. 

Electricity is a major health hazard and can in fact be deadly, so your electrical systems should not be touched unless you know what you’re doing.

Some setups and fixes can be done on your own with online guides, but others should be left to a professional.

If you’re ever unsure, default to hiring a pro and stay safe. 

3. Purchase a 50-amp to 30-amp adapter cord

Most RVs have access to two different power cords: 30 and 50-amp.

With a 50-amp hookup, you can draw quite a bit more electricity than with a 30-amp one. 

However, some parks only have 30 amp hookups so you’ll need to purchase a 50-amp to 30-amp adapter. This will allow you to get 50 amps of power from a 30-amp hookup.

That is, assuming your RV has 50-amp capacity.

Learn more: How to Wire a 50 AMP RV Plug: A Step-by-Step Guide. 

4. Use a polarity tester and surge protector to protect your RV’s electrical system

Not every RV park keeps their hookups in good condition. 

Sometimes, accidents happen that cause an RV’s entire electrical system to blow out, costing you weeks of downtime and thousands of dollars in repairs.

A polarity tester allows you to test the condition of the campground’s wires and tell you if they’re in good condition or not.

A surge protector is also vital for protecting your RV.

It adds an extra layer of protection in the event that a surge of electricity is sent through the wires. This keeps the full charge from being sent through the other end of the hookup and into your RV, thereby protecting it from a blow out.

Check out our top surge protector recommendation here: RV EMS vs Surge Protector: Which Is Best for Surge Protection?.