Portable Generators Buying Guide
What is a Portable Generator
If you are looking for a portable generator, you probably already know about this product. However, for those of you out there who are new to portable generators, we’ve begun this guide with a definition and description of the tool.
A portable generator is a device that provide electricity and that can be moved around. More often than not portable generators will be equipped with wheels to help them move easier. They are also comprised of the following components,
- Internal combustion engine: This is the part that runs the generator. They work in the same ways as the internal combustion engines in our vehicles.
- Starter: Again, like a vehicle, the starter starts the internal combustion engine.
- Fuel tank: The fuel tank holds the fuel that keeps the generator running. Portable generators use a variety of fuel types—described in detail below.
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- Alternator: Alternators are the part that produce the electrical current.
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- Outlets: Most portable generators have multiple outlets, as these are the locations where you can plug in electrical devices to be run by the generator.
Portable generators are not meant to be permanent. They are primarily used as a backup power source in case of electrical outage. Depending on the type of portable generator, its power potential, and surge protection, they can work for several hours or days. In a world that is more and more reliant on electricity, it makes a lot of sense—and is the safest option—to consider purchasing a portable generator.
See Our Top Generator Picks for Under 400 bucks
Important Terms
Before we delve further into portable generators, we need to define a few important terms. Knowing these terms will allow you to understand fully the discussion that follows.
Generator Power in Watts
kW (Kilowatts): Kilowatts or kW is the measurement of electrical power. One kW is the equivalent of 1000 Watts. Often you will see kW in relation to measurements of time like an hour. kW hours (kWh) indicate the amount of electrical power needed to run an electrical device for an hour. For example, a device with a kWh of two would need two kW or 2000 Watts of power to run an hour. In general, the higher the kW number, the more electrical power the portable generator produces.
Power Surge / Voltage Spikes
Voltage surges and spikes occur when more electricity than normal courses through the lines. Voltage surges last three nanoseconds or more and voltage spikes are any power surge under three nanoseconds. Both voltage surges and voltage spikes can be very dangerous to electrical equipment.
Voltage surges and spikes can be caused by external factors like lightning strikes or other problems with the electrical grid. Most common voltage surges and spikes that effect portable generators are actually caused by internal sources like turning electrical equipment on and off. The best thing that you can do to protect your portable generator form voltage surges or spike is to purchase a model with a surge protector.
Starting Watts
Some electrical appliances need extra power to start up, this is referred to as starting power. When calculating your energy needs, you need to take into account the starting power, or it could act as a surge that ruins your portable generator.
Running/Continuous Power:
Running/continuous power refers to the amount of power it takes to run an electrical appliance consistently.
Different Types of Generators
When deciding on the right generator for you and your family, there are a few different options to consider. Below we discuss each of the three types of generators in detail and lay out their various pros and cons.
Portable/Conventional
The conventional generator is the most typical type. It uses an internal combustion engine that runs on gas, diesel, propane. This is the type of generator that you will find in more home improvement stores.
There is a reason that convention generators are so common, they come with some definite pros, but have a couple cons as well.
Pros
- They are easy to find, as is their fuel source.
- Portable generators are the cheapest of the three generator options.
- Because portable generators can be moved, they can be used anywhere they are needed.
Cons
- The portable/conventional generators that use gasoline may need a stabilizer to be stored properly.
- They may not come with a battery back-up system.
- They can produce carbon monoxide, so need to be handled with care
- -Propane generators: tanks are bigger, take up space, and use more fuel
Inverter Generators
Inverter generators are a newer addition to the market. They use inverter technology—which relies on magnets to produce electricity in a three-stage process—to produce its power. Inverter generators tend to be more energy efficient than conventional models.
Pros
- Inverter generators are typically small and light, so they fit well in a boat or RV. They can also be moved easier, which makes them perfect for the DIYer.
- Because they are more fuel-efficient, they are better for the environment and save you money in the process.
- The three-stage process of making electricity helps to keep the inverter generator’s noise levels low.
Cons
- The newness of inverter technology means that these generators are significantly more expensive than their conventional counterparts.
- Inverter generators have more complex mechanics, which makes it more likely for them to have problems.
Standby Generators
Standby generators are the only non-portable type of generator. They need to be installed by a professional and are much more powerful than the portable models.
Pros
- Standby generators are programmed to turn on immediately after a power outage, so you don’t have to worry about an interruption to your power supply.
- They have other fuel options than just gas or diesel.
- They tell you when they need maintenance, which takes the guess-work out of their care.
- They provide the most power of any generator type.
Cons
- These are large generators that have to be installed by a professional, which means they can be quite pricey.
- They cannot be moved, so they only provide electrical protection in one location.
Fuel Type
Most portable generators—conventional and inverter—use gas or diesel as their fuel source. But, newer generator models may also use a variety of different fuel types. Here we’ve listed the most common sources of fuel that you will find for your generator.
Gas
The king of generator fuel. Most generators will use gas their fuel. It is a low-cost and highly obtainable fuel sources, but it does have a couple of drawbacks. Most importantly, it needs to be stored, because gas is unavailable during power outages, gas is flammable, and its cost is directly related to a fickle marketplace
Natural Gas
Natural gas is a widely available fuel source, but the technique used to produce it—fracking—is disliked by some people. The generator and your home will also need to be equipped with gas lines, which is an added cost. But, dealing with these negatives mean that you will be getting an extremely efficient and clean fuel.
Diesel
Diesel is another extremely common fuel source for generators. It has a low flammability, is more efficient than gas, and can be started in cold temperatures. However, diesel only lasts a year in storage, it cannot be pumped during power outages, and it creates high level of emissions.
Dual Fuel Generator:
One final option for generator fuel is a product that uses multiple of the fuel sources listed above. This can be helpful because if you run out of one fuel source you can use another. A common combination of fuel is gas or diesel with propane. Since propane stores longer than gas or diesel, this combination allows you to always have fuel on hand for your generator. But, with dual fuel generators you will still have the cons of each fuel source you use. And, a greater number of options means a larger likelihood of something breaking.
Propane
Propane is a clean fuel source and stores much longer than gas or diesel. But, it can be explosive under the correct conditions and it need special lines to run properly. It also will take up more space and cost more to use.
Hydrogen
This fuel source is not at all common, but it has been worked on since the 1800s. Hydrogen generators use that gas primarily sourced from water. This means that the fuel source is clean, not dangerous, and cheap. However, hydrogen generators are extremely rare, and you will likely pay a premium to purchase one.
Portable Generator Features
Deciding on the type of generator and fuel that will work best for you is just the first step in generator purchasing. These machines are extremely important, and so they have many items that need to be considered before you make your purchase. In this buyer’s guide we’ve listed some of the essential factors to keep in mind when finding a portable generator.
Power ratings:
Power is probably the most important factor for portable generators on this list. How much power your portable generator creates determines what and how many electrical appliances you can use at one time. Most portable generators will produce between 3 and 10 kW.
In order to get a realistic figure for your power needs calculate the starting and running power requirements for all the appliances you plan on running on the generator. You can find these numbers in your owner’s manuals. Take the highest number you find, this is the number of watt or kW your portable generator will need. If you plan on running more than one electrical appliances at one time, you will need to add the power requirements for multiple items together to get your power requirements.
Portability:
It is likely that you are interested in portable generators because of their ability to be moved. However, some are more portable than others. A certain model’s portability is determined by its weight, whether or not is has wheels and handles.
If you plan on moving the portable generator a lot, then you need to make sure that you don’t purchase one that is too heavy for you to move alone. Also, the inclusion of a handle or two and large, wide-set wheels will make moving your portable generator much easier.
Surge protection:
As we have mentioned, surges can significantly damage your electrical equipment, and this includes generators. Because some appliances create a power surge when they start, they may create more power than your generator can safely handle. If this happens, the parts on your generator could be damaged.
The best thing that you can do for your portable generator is to purchase one with surge protection. Surge protection protects the circuits in your portable generator form frying if there is an unexpected surge in electricity.
GFCI:
GFCI stands for ground-fault circuit interrupter. On portable generators, the GFCIs are built in and will disrupt an outlet if it detects a potentially dangerous ground fault. Most often these ground faults occur because of water, and GFCIs are requirement for all electrical equipment used outside.
All portable generators should have GFCIs. So, as you are looking for a good model, looking for GFCI in the spec list will ensure that the manufacturer you are investigating is creating legal products. GFCIs can save lives.
Outlets:
Portable generators come with a variety of outlets including 12 volts DC, 120 volts AC, and 240 volts AC. You can also find portable generators with different numbers of outlets. Thus, you will need to know your exact outlet needs.
In order to accurately determine what types and the number of outlets you will need on your portable generator, you should write a list of the appliances you plan on hooking into the generator. For example, you will need outlets that create 240 volts in order to power your home through the generator if an outage occurs. If you need both AC and DC power, you will need to purchase a portable generator than can convert AC power to DC.
Manufacturers of portable generators provide the specifics on the number of outlets and what they can be used for, which can help you determine your own outlet needs.
Fuel gauge:
The fuel gauge on your portable generator tells you have much fuel you have left in the tank. This is important information to have because without fuel the generator will not work. The gauges provide easy-to-read dials that will tell you when you need to add more fuel to your portable generator.
Most generators come with built-in fuel gauges, but you can also always purchase one to install yourself. However, if you are not someone who enjoys working on machines, we recommend buying a portable generator with a fuel gauge already installed.
Run time on fuel tank and fuel efficiency:
Fuel tanks come in different sizes, which will determine how long you can run the portable generator without having to refuel. The bigger the tank, the longer you have. Most portable generators will run seven to nine hours on a single tank.
In addition to size, fuel efficiency will determine how long you can run your portable generator without adding more fuel. Certain fuels—especially propane and natural gas—are more efficient options. They are not used as quickly, and so give you more run-time for your money.
Two Generators Paralleling
Paralleling describes the practice of hooking multiple generators together to create more power. This is especially common in RV or Travel trailer generator use, as it allows you to use more appliances simultaneously. However, not all portable generators will be paralleling compatible. If you hook up generators that are not compatible with paralleling, you could ruin the generator.
If you are someone that needs to parallel their generators, you should look for models that can be paralleled for a long time without either generator being hurt in the process. The products should say in their specification whether they are parallel compatible or not.
Warranty:
Portable generators are an investment. As such, you need to make sure that you are protected. Therefore, it is always better to purchase a portable generator that comes with a multi-year warranty. Most standard warranties should be between two and five years at least and come with the option of purchasing an extended warranty.
The warranty should also cover parts, repairs or replacement of the unit. If something goes wrong with your portable generator, especially if it is a problem from the factory, you should be able to receive the help or replacement you need.
CARB/EPA compliant:
In order to be CARB (California Air Resources Board) and EPA (Environmental Protection Agency) compliant a portable generator has to meet certain specifications regarding the about of carbon emissions and other air pollutants they are allowed to produce. These regulations are in place to ensure that the portable generator is environmentally friendly as well as useful.
In order to guarantee that you can use your portable generator anywhere in the United States, make sure to buy one that is EPA and CARB compliant. If the model you choose is not CARB compliant, you will not be able to use it in California, which can be a big problem for RV and other travelers.
Starting:
Some portable generators are easier to start than others. Some have an electric start with a push button and some use a manual pull start—like a lawnmower. You can also find battery start portable generators, they have a built-in battery for easy starting. The type of start that you choose depends on how much you want to work to get the generator running.
Generator Noise Level
If your looking for the quietest portable generator then focus on decibel levels. Decibel level of generators will vary depending on size and type. All generators are going to produce some noise, that is a given. However, some generators are louder than others. Inverter generators tend to be quieter than conventional models. Plus, smaller generators are not going to produce as much noise.
The general rule of thumb is that any generator rated for over 4 kW of power is not going to be very quiet. Additionally, your fuel source will determine how many decibels of sound your portable generator produces. For example, diesel generators will be louder than gas. Before buying a portable generator research its expected decibel output and consider how and where you will be using it.
A Little More About Power
Because the whole point of portable generators is the electrical power that they produce, we will finish this article by going into a little more depth about those requirements.
How much power do I need?
Accurately calculating your power requirements is essential for choosing the correct portable generator. Since everyone’s power requirements are a little bit different, here are a few general steps to figure out how much power you need.
- Determine what you plan on powering with your generator and what items you plan on running at the same time.
- Look up both their running and starting wattage.
- Add together the wattage for the items that will be run at the same time—make sure you are also factoring in starting power. Calculators like this one from Northern tool can help you with this step.
Depending on what your power requirements add up to, you may want to consider purchasing a portable generator with slightly more energy output, that way you have a little wiggle room in case your power needs increase.
Recreational power requirements?
If you plan on purchasing a portable generator for recreational reasons, your power demands will be much less than someone who is buying a back-up power system for their home. Most recreational generators make only up to 2 kW of power, but they are also the lightest and cheapest generators on the market.
With a recreational portable generator, you will be able to power a fridge, lights, and a single phone charger—or a similar arrangement of power usage. This may not seem like a lot, but for certain scenarios, it may be enough to get you through.
Camping Power requirements
One situation that may call for a recreation portable generator is camping. Your power requirements will depend on what you plan on powering. But, these items will likely be small—like a Smartphone, Radio, Fan, Light, etc. You can use the list here to calculate basic camping electronics and their watt requirements.
RV power requirements
RVing is another scenario that may call for a recreation portable generator. However, when you use an RV, you will likely need slightly more power than you would camping. Most importantly, most RVs have some size of air conditioner and kitchen items like fridges, microwaves, and stoves. If you also plan on equipping your RV with entertainment items like TVs, computers, or radios, your energy requirements will raise.
Conclusion
Portable generators are an extremely useful machine to have on hand. They can make camping, RVing, and other travel much more comfortable. They can also keep your home running smoothly even in a power outage. But, with all the options on the market, buying a portable generator can get overwhelming.
This is why we have created our portable generators buyer’s guide. If you keep all of the factors that we have brought up in this article in mind, your portable generator purchase will go smoothly, and you will have piece-of-mind for many years to come.