If you want to dry camp in your RV (or camp without electrical hookups), an RV battery inverter will go a long way to make that experience easier. These devices are becoming more popular, but many RVs still don’t come with one installed.
What does it do? When do you need an RV battery inverter? Keep reading to find out!
Why An RV Battery Inverter Is Important In Your RV
When you go camping in an RV, you expect to bring the comforts of home with you on the road. However, we often take for granted many appliances and electronics we have readily available to us in our homes. Want to dry your hair after a shower? Is your laptop battery running low and needs to be charged? Want to grab a cold drink out of the fridge?
All of these devices require power. More specifically, they require AC power like you have in your house. Unfortunately, your RV battery system is DC power. We’ll explain this more below.
An RV battery inverter is needed to convert the power coming from your RV battery system into power you can use for many household appliances and electronics. Read on to find out how RV battery inverters work and how to select the best option for your needs.
What Is an RV Battery Inverter?
An RV battery inverter takes the 12 volt DC (direct current) power from your RV batteries and converts it to 120 volt AC (alternating current) power.
Tip: Learn more about current by reading What Are Amps (And Amp-Hours) And Why Do They Matter?
An inverter doesn’t store energy like a battery; it just converts it. You can only run your 120-volt AC devices and appliances for as long as the 12 volt DC voltage from your battery lasts.
DC Power vs. AC Power
Electricity is the movement of electrons through a conductor, like a wire. This movement is called “current.”
In DC (Direct Current) power, the electrons always move in the same direction through the electrical circuit. With AC (Alternating Current) power, the direction the electrons flow alternates very quickly. In the US, the direction changes 60 times every second. We refer to this as 60 hertz (Hz).
An RV has both AC and DC circuits. The DC circuit will usually be 12 volts, which is the same as your battery voltage. In the US, the AC circuit will be 120 volts at 60 Hz. Both circuit types are easy to identify, so you shouldn’t mix them up.
AC circuits are connected to electrical sockets like in your house. DC circuits look like the cigarette lighter port in your car or a USB outlet. If your RV has LED lights, they’ll also be powered by the DC circuit.
How Do RV Battery Inverters Work?
An RV battery inverter takes power from your RV batteries and “inverts” that power from 12 volts DC to 120 volts AC. The inverter does this by first creating an alternating current with a set of electronics.
The problem is that the alternating current is still at 12 volts, so it needs to be increased. This is accomplished by using a transformer to increase the voltage to 120 Volts. Depending on the inverter, they can be used for different DC voltages like 12V, 24V, or even 48V.
RV Inverter vs. RV Converter
We’ve established that an RV battery inverter changes the 12 volt DC power from your RV batteries to 120 volt AC power.
By contrast, an RV converter “converts” the voltage from 120 volt AC power to 12 volt DC power. An RV converter allows you to use AC shore power to run any of your devices that need DC power (such as LEDs, RV appliances, and small electronics) without relying on your batteries. You’ll also need a converter to use shower power to charge your 12-volt battery system.
Pure Sine vs. Modified Sine Wave RV Battery Inverters
There are two different types of RV battery inverters – pure sine wave and modified sine wave. The main differences between them are efficiency (of power use), cost, and the potential for electrical interference or noise in sensitive electronics.
As we discussed earlier, the electron flow in an AC circuit switches directions 60 times every second. However, this doesn’t happen instantly. Instead, the signal looks like a sine wave.
The diagram below compares the output signals from a pure sine wave inverter to a modified sine wave inverter so you can see the difference more clearly. Let’s take a closer look at each option.
As you can see in the comparison above, the pure sine wave inverter produces an output that is nearly a perfect sine wave, hence the name.
The output from a modified sine wave inverter is choppier and can often cause problems for appliances that use AC motors (like a microwave) and sensitive electronics. Even if your devices run on a modified sine wave (and most will), they will likely be less efficient and may have a shorter lifespan.
The main drawback to pure sine inverters is their initial cost. However, over time, the rougher signal from a modified sine inverter can cause your devices to wear out sooner than they typically would. If you end up needing to replace expensive electronics (like a computer) too frequently, you’ll likely be better off spending a little more upfront and buying a pure sine inverter.
Can You Use a Regular Inverter for Lithium Batteries?
If you’re planning to use a lithium battery instead of a lead-acid battery, most inverters will work fine. If you plan to use an inverter charger combo, you’ll need an inverter that supports lithium batteries. This is because the charging circuit for a lead-acid battery is very different from that of a lithium battery.
Before buying an inverter or charger for your lithium battery system, please contact your battery manufacturer to get their recommendation on the best options available.
How To Know What Size RV Battery Inverter You Need
It is pretty straightforward to determine what size RV battery inverter you need. Inverters are sized by their power output which is measured in watts.
Most devices and appliances will have a power rating on them in either watts or their current draw in amps. Since the inverter is sized in watts, if you have a device that only lists the current draw in amps, you’ll need to convert to watts. To convert from amps to watts, multiply the amp rating by 120.
Amps x 120 = Total Watts
Once you know the power consumption of all of your devices in watts, simply add them together to get the total amount of power you need from your inverter.
Since some appliances draw up to twice their rated wattage when starting, you’ll want to choose an inverter with a 15-20% higher output wattage than your total. For example, if you calculated 1,550 watts total, you’ll likely want to get a 2,000-watt inverter.
Disconnect From The Grid With An RV Battery Inverter
An RV battery inverter is a wonderful thing! It allows us to disconnect from shore power and head out away from the crowds without giving up the amenities of home.
Now you can use the information above to help pick out the best inverter for your needs so you can get out and enjoy all of the places your RV can take you.
Want To Learn More About Electrical Systems and Lithium Batteries?
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