What Size Inverter for a Microwave?

Not sure what size inverter you need for your microwave? In this video, I'll walk you through everything you need to know to make sure you're sizing your inverter correctly, whether you're setting up in an RV, off-grid, or just want to understand your microwave’s power demands better.

We'll start by breaking down the power ratings on your microwave. I'll show you how to interpret the numbers you see on the label and what they really mean. I'll even test my own microwave to reveal its true power consumption—spoiler alert: it’s not always what the label says! This test will give you a clear idea of why you should always estimate your inverter needs at nearly double the microwave's advertised power.

Next, we'll explore the common misconception that using a lower power setting can help you get away with a smaller inverter. I'll test this theory by running my microwave on a low setting and showing you why it still pulls the same amount of power. If you're considering an inverter microwave, I’ll explain how these differ and whether they could be a better option for your setup.

Surge power is a major factor for many appliances, but not microwaves. I’ll break down why you don’t need to worry about surge power with microwaves and how my 2,000-watt inverter handles everything, even without surge capacity.

Then, we’ll dive into battery sizing and wiring. I'll show you the exact setup I use, including how to calculate the required battery size and how to wire everything safely. I’ll walk you through two detailed diagrams, covering wire and fuse sizes, so you can confidently set up your system. Whether you're using a single battery or planning a larger setup, I’ll explain how to calculate the amperage, choose the right cables, and size your fuses properly.

Finally, I’ll wrap things up by discussing the importance of using the correct insulation temperature for your cables and when you might need to double up on cables to handle higher current loads. I’ll also touch on NEC regulations and why they matter for your setup.

[danielrodding]

The inverter needs to be so highly dimensioned that sufficient reactive power can be supplied. Here in Germany, transformers, inverters and such things are specified in VA (volt-ampere), and not in Watts. While the rating in Watt means it is for the used (or typically usable) current, the VA ratings include reactive power.

[owolabiadeteye]

Great job, thanks for uploading this great lecture.

[johndoe-egle]

I think you are the only one that shows the actual numbers and calculations !

[Mmmmmmmiwish]

lov all the video's.. you give out great info for us all... can i ask a question .. if i hav a 3000w heater 220-240 v how much would it use in 2mins.. so 3000/60*2=100w then 100w/240v=0.416amps

[jimbaggett]

Hi Nick, do you explain how you set up or the parts you use in your AC side power meter? Since most inverter wattage display meters are inaccurate I think a lot of people would like to set up something accurate like your setup. I've watched a lot of your videos and I apologize if you did cover this previously and I missed it, just point me to the correct video.

[kennethchance]

Hi thank you for sharing your video can you assist me with this I have a 24v/5, 000W inverter I want to used it for my kitchen appliances also TV/washing machine etc what size cable / Fuse ? do I have to used Thanks in Advance.

[esmailalkassir]

Is wiring 2* 1, 5 wires instead of bigger wire for 4000 W can cause issues?

[jimsmith]

I just found your channel.
(Algorithmic)
Thank you and subscribed!

[ianjaeger]

im welding on my 3.6 kva 24 v off solar wind power here in the jungle west africa mig and arc

[sunny-ey]

Out of curiosity, does anyone know why the actual power draw is such higher than the rated power? I recently found same issue on a new microwave, rated input is 1250w, output is 1000w, however the power draw is actually about 1600w.

[glennj]

Iv got a 650 x12v truck micro with 1000w renogy pure sign inverter with a 300 amp lithium batteries all with 35mm cables ( only less than 1m lengths )

[kevinswinyer]

I have a few questions. I live in a Vintage Class C Motorhome, that has a Microwave Oven, and there is a Converter in the Coach for a 30 Amp Service, but because of where I am parked on the property, my power Cable is not long enough to reach the power supply back at the main house, so I have purchased a 2000 watt inverter, and I am planning on having a battery bank of 4 12 Volt Deep Cycle Lead Acid Marine Batteries, hooked together in Parallel with each other, and eventually Solar. My Question is will my 2, 000 watt inverter be large enough to power the RV Microwave, or will I need a larger inverter ?

[LindsayHindle-vf]

When you are calculating amps based on 90% inverter loss shouldn't you multiply the 166 amps by 0.9 rather than divide.

[retrozmachine]

Most ovens have the RF power and the actual draw from the outlet listed on the label.

[ConciergeMed]

Hi. Can you help me please.
I have a motorhome professionally fitted out with electrics. This allows me to charge both the starter battery and leisure battery when hooked up to mains electricity. (I do not have solar panels or use lithium batteries)
My question is, can i hook up to mains electricity to charge my leisure battery as above but at the same time, plug in my portable 2400W power station inside my motorhome socket to charge it up when the mains hook up is still connected?
Hope you can help, thank you.

[muhammadshafiq]

Dear, i appreciate your's efforts. I am from pakistan, can you guide how many books are you written and how can i get these books in pakistan, and i do not have any bank account. Please send me your entire books name. Thank you so much.

[ilanozana]

Generally the rate off power of equipment is power out .not power in.wich is p out times efficency.

[curtchase]

So, an inverter microwave will actually run with reduced output power when you dial down the power? I know standard units just pulse on and off from full power to zero and back. I hate that. The only microwave oven we had that tried hard to overcome that on/off cycling was our old Amana beast from the 1970's. It had a really cool duty cycle where it really pulsed the power, not like the modern junk units do. Example, set power to 50% on the old Amana and would actually cycle the magnatron ON for 1 second, off for 1 second! The food could heat without boiling and sputtering as much. I would love a microwave that actually REDUCED the output power without that stupid pulse on/off stuff.