Off-the-Grid: How Many Watts and Amps Does a Microwave Use?

Off-the-Grid: How Many Watts and Amps Does a Microwave Use?

Microwave ovens are very popular kitchen appliances commonly used for cooking and/or heating food and beverages. Microwave ovens are also very efficient devices, which is very important in many ways.

Due to their convenient nature, microwave ovens are commonly used when camping, on boats, in the RVs, and similar, leading many people to ask themselves, how many watts do their microwave ovens actually use?

Updated: September 7, 2020.

Microwave Ovens – Features and Power Requirements

Most popular microwave ovens range from 500 to 800 watts for compact models and from 800 to 1800 watts for medium to large models, with an average home microwave oven requiring around 1200-1300 watts of power.

In order to find out how many watts your microwave actually needs, check the label on the back/lower side of the microwave – sometimes there is a slight mismatch between the unit’s label (on the front) and the actual wattage requirement.

When being off-the-grid (camping, fishing, hunting, in emergencies, etc.), having a working microwave can be of great help – it can be used for reheating, defrosting, and even cooking and having a warm meal, tea, soup or some other beverage can make a real difference.

When there is no mains power present, there are several options available for running the microwave oven in off-the-grid situations, including:

– portable power stations,

– deep cycle battery combined with a good power inverter,

– power generators.

Best of all, even if your power source is ‘weaker’ than your microwave oven, keep in mind that some microwave ovens come with different power settings (usually 5-10 power levels, sometimes even more), allowing the user to gradually increase the power – when the power level of your microwave oven reaches the maximum power of your power source, decrease it a little bit and feel free to use your microwave while monitoring power and energy levels of your power source.

Note: most microwave ovens feature only a timer, without the option of setting the power.

Of course, this should be avoided, if possible and a properly dimensioned power source should be used to power microwave ovens.

How Many Amps Does a 1200 Watt Microwave Use?

1200 watts is the average power level of the regular kitchen microwave oven.

When being powered by 120V, such microwave use ~10 Amps – we say ‘~10 Amps’ since the nominal voltage of the grid varies a little bit, and when such microwave oven is being powered by a power inverter or power generator, a voltage can vary even more.

But, keep in mind that a 1200 Watt microwave use 10 Amps @120 volts.

In order to power such microwave at full power, 2000 watts power inverter combined with a deep-cycle battery is recommended.

With an average power inverter efficiency of 85%, the battery must be able to provide ~1410 watts:

1200 watts / 0.85 = ~1410 watts

Such power levels are able to provide large batteries (12V, 100Ah, or more), some of them being:

– WindyNation BAT-NSAP12-100: ~20 minutes, down to 10.8 volts,

– Renogy RNG-BATT-AGM12-100: ~20 minutes, down to 10.8 volts,

– Odyssey 31M-PC2150: 30+ minutes, down to 10.05 volts, etc.

Also, portable power generators are also used for powering various appliances, microwave ovens included.

Again, 2000W units are recommended for powering 1200 watts microwaves – such load (~60% of the maximum running watts) will not cause operating issues for most power generators in this class.

Also, such units feature fuel tanks large enough to operate for hours under such load.

Note: after the microwave oven is turned off, if there are no other appliances or loads, be sure to turn the inverters or power generators off, to conserve the energy/fuel.

Power stations rarely feature output power of more than 1000 Watts, and are, as such not suitable for powering 1200 Watts microwave ovens.

However, if you have a microwave in the 500-800 Watts range, a 1000 Watts power station will be able to power smaller and compact microwave ovens, with the operating time depending on the energy stored at the power station battery and the actual required power.

Note: Portable power station is able to power even the larger microwave ovens if the output power of the microwave oven is decreased – just be prepared for a few alarms popped-out circuit breakers when finding the ‘sweet spot’.