What it draws
Microwave
The microwave is here as a demonstration rather than a recommendation. It is one of the largest sustained loads in an ordinary kitchen, and running it from a battery converts a meaningful fraction of your entire reserve into three minutes of reheating.
Typical draw, and the number that actually applies
A household microwave commonly draws somewhere between 900 and 1500 W while running, and the input wattage is higher than the cooking wattage advertised on the front. The nameplate on the back of the unit gives the input figure that matters here.
Read the nameplate. It is usually a sticker on the back, inside a door, or on the power adapter, and the figure printed there is a maximum for that specific unit rather than a typical reading. Any range on this page is a starting point for arithmetic, not a substitute for that label.
- Running watts used here
- 1200 W
- Duty share applied
- Continuous
- Average draw for the estimate
- 1200 W
Hours from a 1024 Wh battery
Estimated hours from the reference battery at 1200 W average draw. An estimate, not a guarantee.
The arithmetic, in full
hours = (rated Wh x 0.85) / average watts
average watts = 1200 W running x 1, continuous = 1200 W
= (1024 x 0.85) / 1200 W = 870 Wh / 1200 W
The estimate below is deliberately shown in hours like every other page, which makes the point better than any warning would. It also exceeds the stated continuous output of every unit in this catalog except the two largest, meaning most of them would refuse the load outright.
The derate of 0.85 covers inverter conversion loss and the share of rated capacity a pack will not hand back. It is one planning figure applied to every unit on this site, not a measurement of any particular model.
Starting surge
This load has no meaningful starting surge. It draws essentially the same at switch-on as it does a minute later, which makes it one of the easy ones: if the continuous output is large enough, the load will run.
Duty cycle
This load draws continuously while it is switched on, so no duty share is applied and the average draw is the running draw. Switching it off is the only thing that reduces it.
How to get by without powering it
Every watt-hour you do not spend is one you still have. These are the moves that cost nothing.
- Eat what does not need heating. This is the entire answer, and it is why a shelf of food that is fine cold belongs in stage zero.
- Use a camp stove or a grill outdoors, following its instructions, and never indoors, in a garage, or on a covered porch.
- Plan meals for the first day around the refrigerator, which is emptying anyway, before touching anything shelf-stable.
- If you do reheat from a battery, understand you are trading a large share of the reserve for a few minutes and decide that deliberately.
Where this sits in the sequence
No stage in this sequence covers this load
- No stage in this sequence covers running a microwave from a portable battery. The draw is large enough that the reserve is spent on reheating rather than on the loads that matter across a long outage, and most units here would refuse it outright.
It appears on this site as an example rather than as a recommendation. The section above is the honest answer, and the arithmetic higher up the page is why.
Related gear
Products live on the gear pages rather than here, because the decision on this page is about arithmetic and the decision there is about hardware.