How Many Watts and Amps Does a Microwave Use
Microwave ovens are commonly used not only at homes as an everyday household appliance, but also when camping, on hunting/fishing trips, and at all other off-the-grid situations, emergencies included.
When powering microwaves when the mains power is off, it is good to know a few things about microwaves, their power requirements, and similar.
Published: February 23, 2021.
Microwave Oven Wattage
Microwave ovens vary in size and thus, strength. Smaller, compact units are rated at 500-800 watts (~4.2 - 6.7 Amps @120 volts), while common household microwaves range between 800 and 1800 watts (~6.7 - 15 Amps @120 volts), with most units being rated between 900 and 1200 watts (7.5 - 10 Amps @120 volts).
Microwave ovens are very efficient appliances and are excellent not only for cooking, but also for heating and defrosting of food, soups, teas, etc.
In the off-the-grid situations, having a warm meal/drink can make a huge difference in how one feels - that is the reason why it is perhaps even more important to know how to power a microwave oven in emergencies and not, for example, a TV.
As usual, there are three most popular options on how to power microwave oven in the off-the-grid situations:
Power stations use the energy stored at onboard lithium battery to power external load, in this case, microwave oven.
With most ovens being rated at 900-1200 watts, our hypothetical power station must be able to provide at least 1200 running watts, preferably 1500 running watts.
Since microwaves are rarely the only load connected to the power station, having 2000 watts power station is recommended - yes, such power station can power both 1200 watts microwave and 32-inch LCD TV, except that operating time on the single battery charge may be relatively short.
The main advantages of the power stations is that they may be stored for longer periods of time and ready to be used at the moment notice, they can be used indoors since they don't release any fumes, they are almost silent during use, etc.
On the other hand, the energy stored in the battery may be limited. Also, the battery must be recharged every month or so, depending on the model.
Deep Cycle Battery + Power Inverter
Power inverters connected to deep cycle batteries are not as portable as 'portable power stations', but may feature much longer operating times on the single battery charge, and also, may be in the end cheaper investment.
For example, if you have a 1000W microwave that runs at a max. power (1000W), and the power inverter features 85% efficiency, then the battery must be able to provide ~1180 watts.
Again, since the microwaves are rarely the only load connected to such power inverter, having 2000 watts power inverter is recommended.
Battery sizing depends on the required runtime on the single battery charge - for example, most BCI Group 4D and 8D batteries are able to provide 1180 watts for at least one hour, without the voltage dropping below 10.8 volts.
Compact and relatively lightweight portable inverter generators in 1500-2000 watts class can easily provide power for 900-1200 watts microwaves, with 2000 watts generators being able to provide power even to 1800 watts microwaves for hours.
Actual runtime depends on the fuel tank capacity and required power - microwaves are rarely the only load connected to the power generators in the off-the-grid situations.
But, since microwaves don't require any additional starting power, with 900-1200 running watts, most 2000 watts power generators may operate for at least 3-6 hours under such load.
Note: under no circumstances DO NOT operate power generators indoors - they must be operated outdoors since they release dangerous and poisonous fumes. For exact operational procedures, check the power generator's User's Manual.
Long Story Short: Most people don't even notice the importance of microwave ovens in the modern households until the microwave breaks down, or until the electricity is gone.
While large 1800 watts microwave ovens may be challenging to power for hours (although, who needs a microwave to operate for that long?), especially during longer power outages, smaller and more compact 900-1200 watts units offer the user with several choices.
Power generators must be operated outdoors, but may provide the longest operating time at acceptable costs. For indoor use, go for either power stations or for the combination of large(r) deep cycle battery and the power inverter.