How to Choose the Best Portable Generator

Need more power off-grid? A portable generator is the perfect option and understanding capacities, costs, plus the variety of features and benefits will result in getting the right unit to run all the desired systems and electronics.

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Words by Perry Mack

When we started looking for generators it became apparent that there are almost as many portable generators as there are stars in the sky, some with similarly stratospheric prices. Why are similar wattage producing generators priced between $500 and $3500? If you have some flexibility in your budget, how do you decide what you need, what you want and which unit provides the highest feature/quality/cost benefits?

Several features start to show themselves when you begin to shop. You decide what’s most important, and how many of the features you are willing to pay for. 

Size Matters 

This is described two ways – max (or surge or starting) power and running power. Max is the highest short-term boost the generator can manage to get devices like your A/C going. We mention the A/C as these systems often have the largest difference between running and starting power. 

For instance, a 13,500 BTU A/C may need 1600 watts (W) to run but 2800 W to start. But how much running power do you need? If your A/C unit requires 2800 W to start, and you’d like to make coffee at the same time (1000 W) and microwave a bagel (1000W) you’ll need a generator that produces 4800 starting watts and (using our A/C example) 3600 running watts minimum. Add the largest starting watt in your list to the running watts of everything else you want to use at the same time. This way, you can be heating your bagel and making coffee when you decide to start your A/C unit.

You can find a handy generator selector from Champion here https://www.championpowerequipment.com/generator-selector/. However, your most accurate answer will come from looking at the appliances you actually own and frequently use. Power consumption varies drastically from one microwave, coffee maker or A/C to the next.

Caveat Emptor – Let the Buyer Beware

If you like to research (and shop) online, download the user manual of the generator as it will provide you with more accurate specifications and warranty details than the website listing. Some generators are named 2000W for their max power, while others are named for their continuous rated output, which means a ‘1600’ could be just as powerful as a ‘2000’.

Runtime is also a number that is provided in a number of ways. For the generators we’re considering, it’s the length of time that a generator will run on a tank of gas. The number to watch for is the Rated Load. One may state 10 hours at ¼ (25 percent) of the rated load while another could be five hours at ½ (50 percent) of the rated load. They are both equal. A 2000 running watt generator can run at 500 W for 10 hours or 1000 W for 5 hours. 

Weight is another number to look at closely. Dry weight is the weight of the generator with no fluids. If a 68 kg (150 lb) generator is a unit you are comfortable lifting (wow) or will max out your carrier, make sure you add in the oil and fuel. If it has a full 13 L (3.4 gal) tank, this will add 9.7 kg (21.42 lb) for a total of 78 kg (with oil). A bigger tank offers a longer run time but could prove more than you want to handle.

Dual Fuel vs Gas Only

Although some generators are fueled by diesel, most RV-centric generators are fueled by gas and/or propane. The propane option is attractive to us since our Silverado 3500HD is diesel-powered, which means we would have to carry an additional fuel can for the generator. If the gas runs out, we would have to run out to buy more. With dual fuel, we can connect to the RV’s propane tanks and boondock longer. 

The other advantage of propane is that if you’re able to connect to a large supply, you’ll be able to run your generator without continually filling the gas tank – i.e. boondocking through a hot summer night and being unrestricted by the size of the generator’s fuel tank. The dual-fuel generators cost more but the versatility may be worth it. One item to be aware of is that the power output with propane is usually less than that of gas, so choose the size accordingly.

Bring on the Noise

Low noise is important if you plan to stay in campgrounds and parks where, aside from an enforced quiet time, there is also a restriction on the decibel (dB) level, which may include the noise your generator makes. Check with the park you plan to visit as the restrictions differ from park to park.

As an example, 50 to 60 dB is roughly the level of normal conversation. The sound level as measured in decibels (dB) is not a linear scale. A 3 dB increase doubles the volume of noise, a 10 dB increase is by a factor of ten (ten times the noise).

 If you are comparing two generators, one with a rating of 68 dB (a common number) and another with 58 dB – this is a significant difference. The latter is ten times quieter if the rating is measured at the same distance. The dB rating is most often measured at 7 m (21 ft). Manufacturers of noisy generators could provide a dB at a greater distance (i.e. 15 m (50 ft)) to keep the unit’s noise rating competitive at first glance. Whenever possible, find out at what distance the generator noise was measured. After all, you’re RVing to enjoy wildlife, not scare it away.

How Big is Big Enough

It may just be a male trait but guys often think that bigger is always better. Why settle for a 2000 W unit when they come in sizes of over 10,000 W? Think of all the things you could power up, like your house in the event of a blackout! Can you say ice storm? Unfortunately, bigger means heavier and the lack of portability deflated our desire for a home-based power generating station. Smaller 2000 W generators can weigh roughly 22.5 kg (50 lb) while units more than 10,000 W can be over 90 kg (200 lb). If you are considering a larger unit (45 kg (100 lb) or heavier), look at one with wheels.

Then there’s the cost and storage. More output requires a larger engine, which means a higher purchase price and higher fuel costs. You will also have to store it somewhere. Lower power generators are smaller, lighter and take up less space.

Get it Started

Do you despise pulling on a recoil start like the lawnmowers of old? Then put an electric start on your checklist. Expect this feature to add some weight and expense to account for the battery. Electric start can also come with a remote start. Sounds extravagant? Think about lying in bed boondocking on a hot summer night. Push a button to start the generator and the A/C without leaving the RV.  Or wake up on a cold morning and remote start your genny to make that first cup of coffee in your PJ’s.

Contractor vs Inverter Generators

‘Open’ or ‘contractor’ generators are cheaper – a lot cheaper. But inverter generators are the preferred choice for RVing. Typically, the contractor style is much louder as it has no enclosure and draws power directly from the generator, which must run at 3600 rpm to produce 120V AC at a frequency of 60Hz, typical of households across North America. 

However, when the engine speed changes, so does the frequency. Its design makes it susceptible to power surges and declines, which isn’t a problem while running most power tools on a job site. However, this corrupted power can damage refrigerators, A/C units, computers, phones and flat-screen TVs, anything with a microprocessor. 

The engine in an inverter generator isn’t driving a generator but rather an alternator. Like the one in your car, it produces 12V DC power, then the onboard microprocessor-controlled inverter turns it into clean, stable AC power, consistent with what the utility company provides your home. Great for sensitive electronics, inverter generators are also typically built with a sound-attenuating enclosure resulting in low noise volumes in the 50 to 60 dB range.

Your RV likely has a converter, not an inverter. When connected to shore power, the converter takes the AC current and changes it to DC to charge your batteries and run the 12V systems in your RV like lights, pumps, fans etc. It doesn’t clean up the AC power, which flows ‘as is’ to units like your A/C, TV, microwave and AC outlets.

Lower fuel consumption means longer run times for similar fuel capacities (and lower fuel costs and environmental impact). Look for a feature labelled economy- or eco-mode. This feature is found in inverter generators where an idle control is built-in to adjust the engine speed to only run fast enough to provide the power for the appliances you are using. 

As previously mentioned, the typical contractor generator has to run at a constant 3600 rpm to create 60Hz power, but it does so regardless of how little power you are using. The inverter generator can produce 60 Hz at varying RPM. With an eco-mode, there will be a 20 to 40 percent reduction in fuel use and corresponding exhaust emissions and noise.

Double Up

With certain models, you can almost double your power by connecting two compatible inverter generators with either a parallel wire or parallel kit. Compared to a single large unit, the benefits are you only have to haul around as much power as you need, and moving one 22.5 kg (50 lb) unit at a time is easier than a single 90 kg (100 lb) unit. Depending on the size of your generators, you may use two for RVing, which will allow the ability to run multiple electronics including an A/C unit (or when you have a blackout at home), but then you use one for tailgating or other activities like boating.

Stay Connected

Not every generator is equipped with the same number or type of outlets. Most of us need a TT-30R outlet (often prefixed with NEMA that stands for the National Electrical Manufacturers Association) that’s also referred to as an RV30 outlet. The TT stands for travel trailer and the 30 is for 30 amps. The other common RV outlet is a 14-50R (R stands for receptacle and 50 for 50 amps). These are often called RV Ready generators since you can use your RV’s shorepower cord to connect to the generator.

While there are adapters available to switch to different outlets, the amp number is important since adapters can only adapt down. For instance, you can change from 50 amps to 30 amps but not 30 to 50. Most generators (if not all) will also have 120V 15A receptacle(s) that look like the ones in your home and some will have DC outlets as well as USB ports.

When shopping for a portable RV generator you’ll find there are economy brands like PowerFist, Firman and Champion that are significantly less expensive than those generators from Honda and Yamaha. For instance, at the time of writing, a 2000W PowerFist is $550 CAD and Costco is selling a 200W Firman for $400 CAD, while a comparably equipped 2000W Yamaha EF2000IS is $1349. After comparing several models, we discovered that the extra dollars for a Honda and Yamaha buy you better reliability, lower noise production, lighter weight, longer run time, better fuel efficiency, as well as cleaner, more consistent power production.

Rather than go the easy route, you can purchase an economy brand but to be safe, buy them from a reliable local dealer with hassle-free return policies. Mass production of cheaper units increases the likelihood of defective parts resulting in a generator that doesn’t last. Once again, we find that you get what you pay for. Considering the difference in cost, you could buy two (or three) of the economy units compared to a premium brand.

We tested two 2000W (max) PowerFist inverter generators with a stated 1600 running watts each and a parallel kit. They didn’t have any convenient features (i.e. remote start). After installing a SoftStartRV on the A/C unit, a single 2000 W unit was able to get our 13,500 BTU A/C system started - an impressive feat since the starting wattage is roughly 2800 W – far more than the little genny’s capabilities. And we hoped it would be able to keep it running. However,  after five minutes the little genny was overloaded and shut down. The 1600 W running power wasn’t enough. In parallel, the two units would have no problem since the combined running power is 3000 W. This leaves enough power to make coffee or run the microwave while the A/C is on (but not all three simultaneously).

The SofStartRV device is one trick to getting away with a smaller generator. It installs on your A/C unit and for roughly $300 CAD, you can easily save on buying a larger generator while also enjoying the lighter weight, lower noise levels, improved fuel economy and lower emissions of a smaller generator. If you have two A/C units, you can install a SoftStartRV on each one with the same effect; run both A/C units with a smaller, less expensive generator.

A generator is a very useful accessory to own for RVing, camping, tailgating and boating. Aside from running modern conveniences, it will also charge a vehicle, RV and communication batteries to make it safer while you are enjoying all mother nature has to offer. You now have the tools to shop for the perfect generator and find the style, size and features you need, want and can afford. Power up! 

Portable Generator Tips

Most generators need some break-in time and an oil change or two before use. We don’t recommend you buy one on the way to your week or weekend vacation. Buy it in advance so you can break it in around home and test it. Every manufacturer builds the occasional lemon so it’s better to find out how it works before you need to depend on your new generator.

Like most 4-stroke engines generators run better on higher octane gasoline. For the extra few bucks, your generator will run longer at lower rpm when you use the best fuel.

The decibel level for inverter generators is usually described as economy mode, typically at 25 percent load. Larger generators have more powerful engines that don’t have to work as hard as smaller wattage generators to output the same power. This means a 4000 running watt generator producing 1000 W, will be at its rated noise level, while the 2000 running watt generator producing 1000 W will not. The small genny will be significantly louder if they are rated for the same decibel level.