RV electricity basics 

An RV generator provides the electricity to various equipment and appliances within your RV. It feeds the electricity via the circuit breaker panel to these equipment and appliances. It also provides the power to operate your converter/charger, which charges your RV house batteries.  

RV generators come in many sizes ranging from 2,500- to 12,500-watt generators. Their basic working principles remain the same. The internal combustion engine converts the chemical energy stored in the fuel to mechanical energy, rotation. The alternator, coupled to the engine, converts this mechanical energy to electrical energy. This electrical energy then flows to your RV’s circuit breaker panel to feed the loads, equipment and appliances within your RV. 

Your RV’s house batteries and shore power, when connected, are the other sources of electrical energy for the appliances within your RV.   

There are three key energy and power terms associated with RV generators: 

1. Amperage (Amps) is a representation of the amount of current flowing in a wire or conductor. The size of the wires and internal breakers determines the RV's amp capacity. Most modern RVs feature wiring for 30 or 50amp shore power. 
2. Voltage (Volts) is a representation of the amount of electrical potential present. Typically for an RV, this is 120 VAC or 120/240 VAC when running from shore power, generator, or onboard invertor. The voltage is 12 VDC when operating from batteries. Many interior lights, absorption refrigerators, liquid propane furnaces and other appliances operate on 12 VDC. Modern inverters take 12 VDC and convert it to 120 or 240 AC to operate appliances when shore power or a generator is not present. 
3. Wattage (Watts) is the true, “apples to apples” representation of power. Wattage is simply the multiplication of voltage and amps (voltage x amps = watts).   

Comparison of Gas, LP and diesel RV generators

Liquid Propane (LP), gasoline and diesel are the most common fuel options for RV generators.  

LP and gas generators generally have a lower initial cost than diesel units. LP and gas generators are also often smaller and lighter weight, allowing for more flexibility in the floor plan of large RVs. They also have less exhaust fume smell. Besides carbureted gasoline and LP generators, electronic fuel injected (EFI) gasoline RV generators are also available. The EFI technology used in Onan QG RV generator models is the same technology used in the automotive industry for more than 30 years. 

All these benefits might make you think LP and gas generators are superior to diesel generators, but each fuel option has its own advantages. 

Diesel generators have a much longer engine life than gasoline or LP generators. They also consume less fuel; moreover, diesel fuel usually costs less than LP fuel. This combination of lower fuel consumption and fuel price brings additional savings for diesel generator users. A diesel generator gives you a common fuel system and the convenience of operating your generator from the vehicle’s main fuel supply. Many of the diesel RV generators, including the Onan Quiet Diesel Series, dramatically lower noise, vibration, and harshness levels too. 

The RV generator best for you depends on how you use it and your own personal preferences.

What is an inverter generator?

Inverter generators can produce high quality inverted electrical output especially suited for sensitive RV loads such as laptops and smart devices.  

RV generators, inverter or conventional, use an internal combustion engine and an alternator to produce electricity. Alternators produce electricity in the form of alternating current (AC). The quality of this AC electrical output reduces as the engine speed changes. A lower quality AC output could damage sensitive electronics such as mobile phones and laptops. 

An inverter generator features a built-in inverter circuit. This inverter circuit first rectifies the AC output of the alternator into direct current (DC), and then inverts the DC back to AC. This initial AC to DC, and the following DC to AC conversions, ensures the resulting AC output is high quality independent of the changes in engine speed. This ability to change engine speed without impacting the quality of electrical output also offers benefits. These benefits include reduced noise, vibration, and fuel consumption for the generator. 

The technology used in inverter generators often makes them more expensive than conventional generators.  

A conventional generator does also produce high quality electrical output but needs to operate at a fixed speed to accomplish It. For many RV applications, conventional generators run at 3,600 RPM to produce high quality electrical output.  

Finding the quiet RV generator you need 

60 decibels (dB(A)) is the sound of a normal human conversation. 80 dB(A) is like curbside on a street with busy traffic. 90 dB(A) is like the noise of a rotary mower.

There is not an official definition of “quiet” when it comes to RV generators, but an important measure is the National Park Service’s (NPS) sound level requirements: 60 dB(A) at 50 ft.

To meet those requirements, your RV generator would need to measure a noise level around 70 dB(A) or less at 10 ft. This is much quieter than NPS’ requirements and offers you the comfort you need.

Finding the quiet RV generator you need is not an easy task. Here are three important aspects you should consider when comparing the quietness of different generators:

• Distance at which quietness is measured 
• Load level at which noise is measured 
• The angle the noise is measured 

The best sales, service and support

• Find a Local Dealer or Distributor
• Find a CoachCare RV Service Center

Portable generators for RV 

There are two popular generator options for RV owners: portable generators and fixed-mount RV generators.  

Portable generators are not built-into your vehicle. This brings the advantage of easy access for maintenance. Portable generators’ power output ranges from 1,000 to 10,000 watts, but many are at the lower end of this range when it comes to RV applications. Most portable generators use gasoline or LP as their fuel. Portable generators can’t use the fuel from the RV’s fuel tanks; instead, you re-fuel them separately. Portable generators shouldn’t be in use while your vehicle is in motion. Portable generators can be re-purposed beyond your RV. You can use a portable generator at a worksite, tailgating or at your home, only for selected appliances. Portable generators are a good choice for campers and RVs that do not have a dedicated compartment for built-in RV generators.

Fixed-mount RV generators come installed within your vehicle, and allow for push-button and auto start functionalities to your RV. RV generators provide higher power output, ranging from 2,500 to 12,500 watts. They can work with a diverse set of fuels including diesel, gasoline and LP. Frequently, they simply use the RV’s fuel tank. This often results in longer working hours between refuels, as RV generators can be operating while your vehicle is in motion. For example, you can power your roof air conditioner using the RV generator while the RV is in motion. RV generators are the only choice for large Class A and Class C RVs with many amenities and multiple air conditioners.  

Onan generators for RVs

The Onan generators product line-up is customized for RV applications and manufactured by Cummins Inc. Onan generators are the best-selling line of generators in RV history. The one millionth Onan generator was produced in 1995, and two millionth Onan generator was produced in 2010.  

The Onan Corporation began its journey in 1920 as a family-owned business founded by David W. Onan with one employee. One of the first products of the company was the “Onan Ten-Lite Generator,” since it had enough power to provide for ten 30-watt light bulbs. Over the years Onan generators introduced many firsts to RV generators. In 1996, Onan generators featured the first variable speed inverter-based generator. In 2000, Onan generators featured the first electronic fuel-injected RV generator. Today, most Onan generators are still manufactured in Fridley, Minnesota (U.S.). These Onan generators are supported by the industry’s largest service network stretching across all 50 states and Canada. 

Onan generators for RV applications range from 2,500 to 12,500 watts. From smaller gasoline and propane models to larger diesel-powered models for bus-type Class A RVs, there’s a model for whatever type of RVing you’re interested in.

The new Onan QG 2800i / 2500i LP is a high efficiency gasoline RV generator that offers quiet operation and vibration levels.

Best generator for RV air conditioner 

Two of the most important loads on an RV are air conditioner(s) and the converter or battery charger. There are two reasons why air conditioner(s) are important loads.  

First, is due to their average required wattage. A typical air conditioner requires 1,200 to 2,400 running watts, which is higher than many other appliances within your RV. 

Second, is the fact that air conditioners are motor-driven appliances. These electric motors can draw up to three times more power during the first few seconds of startup than during normal operation. While this is common for all electric motors, it is especially true for air conditioners if the compressor tries to start against built-up high pressure in its refrigeration system.  

The best generator for the RV air conditioner is the one that can successfully address both aspects. The generator needs to have the power capacity to start the air conditioner and have spare power to allow you to use other appliances. 

For example, the Onan QD 3200 RV generator can run one rooftop air conditioner with power to spare. The Onan QD 6000 can run two 15,000 BTU air conditioners with power to spare, and the Onan QD 10000 can run three air conditioners with power to spare.