I found the 3L Instant Pot Duo Mini on sale after Christmas and I have fallen in love. I am so enamoured with using it in the van that we are replacing the MSW inverter with pure sine to make sure its electronics don't get trashed.
The Kill-a-Watt tells me that it's maximum power draw is about 750W. I have yet to see it draw power after getting up to pressure, even after 15-20 minutes. So far, the biggest draw I've seen--starting with 2 cups of very cold water--was 15Ah, which translates to 7.5% of our 200Ah battery capacity.
We have heretofore resisted cooking in the van because of odor and humidity. My solution for venting the Instant Pot begins with a "steam release accessory" from Amazon
I added a tube of waterproof fabric to divert the steam into a bottle of water. It works well.
Mac & Cheese, rice, these are super easy. For a real recipe, so far meatloaf and potatoes are my biggest success:
Cube (1/2"?) a couple of small potatoes and put them in the bottom of the pot with a cup of water.
Put the trivit on top of the potatoes. My potatoes and water came about to the level of the trivit.
Make your favorite meat loaf with 1 pound hamburger--I made 1/2 the Ann Landers recipe. When I make this in the van, I will don a disposable glove before scrunching with my fingers on a paper plate.
Form the meatloaf into a disc about 2" thick and put it on a piece of aluminum foil big enough to come up the sides and hold the fat--unless you want the fat in your potatoes which would taste unhealthily delicious. It's important, though, that at least two ends of the foil be tall enough that you will be able to grab it to remove the hot meatloaf. (Recipes call this a "sling".). The meatloaf itself retained its integrity quite well
Pressure cook for 15 minutes, quick release. Potatoes were a bit mushy, but just fine to accompany the meatloaf.