Running the Microwave on Battery Power

Trailpixie

I am looking for someone with real-world experience to validate my expectations for the microwave in my new TAB 360 with Lithium upgrade. The Upgrade carries 270 AH of allegedly usable power.

By my ballpark calculations

• At 12.5 volts the 1000 watt microwave would use about about 75-80 amp hours.
• That would be  about 1.3 AH per minute.
• A cup of water takes about 2-3 minutes to boil, so a cup of water would take about 4 or 5 AH to boil.

Assuming I am camping in sun, it sounds like the microwave is totally fine for cooking while boondocking.

What are real-world experiences with using a microwave while boondocking ?

AnOldUR

Even with the lose of efficiency using an inverter, your numbers are a good estimate. The 1000W microwave will draw about an amp and a half per minute. That's a lot of boiled water.

pthomas745

The numbers for the amp hour use are good as far as they go.  I've used an Insta Pot and a small hair dryer to see how this would go, and for just a few minutes, the amp hour usage is acceptable with so many amp hours available.

The question would be the initial draw of the microwave when it starts up.  When you say you have the "Lithium Upgrade", you mention the two batteries, but you do not mention what inverter you have.  The 3000 Watt Multiplus would "probably" not be an issue.  But, the 1200 Watt AIM1200 probably would have issues of that large initial power draw when the microwave starts.

Horigan

@Trailpixie
Your numbers are close.  Some considerations.
Pulling 1000W from a 12.5V circuit requires 80 amps, not amp-hours.  You need to consider the efficiency loss of the inverter, so I would assume 90 amps DC to get 1000W of AC power from the inverter.  Pulling 90 amps for a minute consumes 1.5 amp-hours from the battery.

Maxcamp

Results from a different setup.  I hardwired a 2000w inverter from our 200ah battery setup, with a manual rotary transfer switch to the  Wefco/PD converter.
 
With no charging sources:
Inverter draws 1.1 to 3 amps with no load.  With microwave on draws 91a to 120 amps.  We can boil a quart of thick stew in 10 to 14 minutes and draw down batteries less than 10%. 
 Easily recharged next day.  Love it!
FYI AC unit draws 65 to 80 amps.

No need to set up remote propane stove.  Never use onboard stove due to heat load and vapors.  

Binghi

I have two no-go’s when boondocking: air-conditioning and microwave oven. Those two require too much power. Really don’t miss microwaving much because I never cook with it and you can reheat stuff on the stove. You definitely can boil water better on the stove.