How Much Wattage Do I Need in My Portable Generator?

How Much Wattage Do I Need in My Portable Generator?

Many of us understand technical measurements and units but have difficulty visualizing them in a meaningful way. Take the size of Australia, for example—it’s undoubtedly large, but estimating its area in square kilometers can easily result in a wildly inaccurate guess.

The country actually spans more than 7.5 million km².

In a similar way, you might understand wattage or watts as units of power. But, how much is a lot? 1000, 5000 or 8000 watts?

The electrical power you need will depend on what you intend to connect and power up from your portable generator. Read on to find out which generator size is for you and your needs.

Why Understanding How Much Power You Need is Important

Selecting the right generator size is essential for efficiency, cost-effectiveness, and performance. A generator with extra capacity prevents overloading and extends engine life, but excessive oversizing increases upfront costs, fuel consumption, and maintenance. Conversely, an undersized generator may fail to power essential appliances, overload easily, and produce unstable voltage that can damage electronics. To ensure reliable operation, calculate total power needs, including surge loads, and choose a generator with around 20-30% extra capacity while aiming to run it within 50-80% of its rated load for optimal efficiency.

Running and Startup Power

The size of a quiet petrol generator should be determined by the total power demand of the appliances it will support, factoring in both running wattage and starting (surge) wattage. Many motor-driven devices, such as refrigerators, air conditioners, and compressors, require a brief but substantial surge of power at startup before stabilizing at a lower operating wattage. In contrast, resistive loads like LED lights and most power tools maintain a more consistent power draw. Selecting a generator with sufficient peak capacity ensures stable operation, prevents voltage fluctuations, and protects sensitive electronics from potential damage due to inadequate power supply.

A Handy Guide to Appliances and Wattage Requirements

Here are 2 lists containing some of the more common examples of home appliances that you might need to power from a generator. Items in the first list do not require extra power that can cause a surge when you power them up. Items in the second list do require extra start-up power.

LIST 1 (No Extra Starting Watts Needed)

 

Running Watts

Gardening Trimmers:                              500 watts

Lawnmowers and chain saws:              1200 watts

70w Light Bulbs:                                       70 watts

Computer with 17” screen:                     450 watts

Security System and Colour TV (27”):    350 watts

Coffee Maker:                                       1000 watts

Electric Kettle:                                       2200 watts

Lamps:                                                    100 watts

Electric Stove (6” element):                   1600 watts

2 x smartphone chargers                          50 watts

 

LIST 2 (Extra Starting Watts Needed)

 

Running Watts                          Starting Watts

Medium Fridge/Freezer:                 350 watts                                        700 watts

Microwave (750w)                             750 watts                                         950 watts

Well Pump                                           500 watts                                      1000 watts

½ HP Garage Door                            450 watts                                       900 watts

Washing Machine                              750 watts                                      1500 watts

Sump Pump ½ HP                             500 watts                                      1000 watts

Fans                                                     200 watts                                         400 watts

 

Electric kettles are among the most power-intensive household appliances, drawing significant wattage during operation. To optimize generator efficiency and reduce unnecessary load, consider using a portable gas burner or an alternative heating method for boiling water when running on backup power.

A Key Benefit of Maxwatt Petrol Generator Sets

You should never overload a portable generator. All Maxwatt portable petrol generators can, however, offer a surge to their regular output. This is always for a short period of time, during startups, for example.

Take the 13.5kVA Maxwatt generator. It can deliver up to 10000 running Watts and 11000 starting Watts. When generators run for prolonged periods with an overload, several problems can occur. These include:

  • The engine overheating
  • The alternator overheating causing the coils to burn out
  • A breakdown in oil consistency leads to engine failure
  • A reduced lifespan for the generator

How to Calculate the Number of Watts You Need

Let’s look at the Maxwatt 8000-watt generator. It can provide 8000 starting watts and 7000 running watts.  The generator can power multiple appliances at the same time, as long as their combined starting wattage remains below 8000W and their total running wattage does not exceed 7000W, ensuring safe and efficient operation within its rated capacity.

You should make your calculations well in advance so that there’s no room for error in an emergency. You could even make your own chart with the starting and running watts of all of your own devices.

Compile a list of essential and optional appliances you may need to power during a short-term outage or extended blackout, ensuring your generator can support their combined wattage requirements. Total up the wattage needed and ensure it is less than the maximum your portable generator can comfortably cope with.

Weight, Noise and Electric Start

When selecting a generator, factors such as wattage, weight, and noise levels are critical considerations. Our compact models feature an integrated ergonomic lifting handle, allowing for easy single-person transport. For larger units, multiple lifting points, Never-Flat wheels, and sturdy foldable handles provide enhanced mobility; however, we recommend a two-person lift or the use of a mechanical aid for safe handling.

Our inverter generators are the quietest in the Maxwatt range, featuring low-tone mufflers, ECO-throttle technology, and double-insulated acoustic enclosures to minimize noise levels to as low as 59 dB(A).

The following electric start models—MX3000IY, 4500IS, 6000IS, 6500IS, 7000ES, 9000ES, 9000AS, 8000IS, and 13000AS—are equipped with a 12V battery for effortless startup.  However, each unit also includes a built-in recoil starter for manual operation, ensuring reliability in any scenario.

Maxwatt Petrol Generators Have You Covered

Maxwatt offers a wide range of portable generators.  The ideal generator size depends on the number of appliances you need to power and their individual wattage requirements. Explore our range of quiet, high-performance generators to find the best fit for your power needs.

Assess your total wattage demand and choose the right model today.

 

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