Why electric cooking does not work on a battery
Cooking makes heat, and making heat with electricity is the least efficient use of stored energy there is.
| Appliance | Draw | From a 2,000Wh battery |
|---|
| Electric hot plate or griddle | 1,200-1,800 W | About an hour, then nothing else works either |
|---|
| Kettle | 1,200-1,500 W | Fine — three minutes is about 70Wh |
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| Microwave | 1,000-1,500 W | Fine in bursts — four minutes is about 100Wh |
|---|
| Electric oven | 2,000-5,000 W | Not viable at any portable size |
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| Slow cooker | 200-300 W | Genuinely viable — six hours is under 2,000Wh |
|---|
| Coffee maker, drip | ~1,000 W | Fine for one brew cycle |
|---|
Draw figures are working estimates from typical appliance ratings rather than manufacturer measurements; runtimes are calculated with this site's stated 85% inverter efficiency. The pattern is what matters: short high-power bursts are affordable, sustained heat is not.
The exception worth noticing is the slow cooker. At 200-300W it is the one genuinely electric way to cook a real meal on a battery — six hours of it costs less than an hour of a griddle.
The safety rule, which is the whole page
Every year, outage-related carbon monoxide deaths include people cooking with fuel indoors. The mechanisms are boringly consistent:
- A charcoal grill brought into a garage or onto a covered porch because it is raining.
- A camp stove used on a kitchen counter because it is cold outside.
- A gas oven left open to warm a room, which is a heating mistake rather than a cooking one but kills the same way.
Ready.gov states it plainly: "Only use generators and grills outdoors and away from windows and never heat your home with a gas stovetop or oven."
Charcoal deserves a separate line because it is the worst of them. Burning charcoal produces very high concentrations of carbon monoxide and it continues after the flames are out — a grill smouldering in a garage overnight has killed whole households. Charcoal is never used indoors, in a garage, on a covered porch, or in a tent, under any circumstances.
What works, in order
1. A gas range you can light by hand. If your cooktop is gas, the burners will usually light with a match even when the electronic igniter has no power. The oven generally will not, because its safety valve is electric. This is the easiest answer and a lot of people do not realize they have it.
2. A propane camp stove, outdoors. Two burners, real pans, wind protection, and about an hour on high per small cylinder. This is the purpose-built answer.
3. A grill, outdoors. Gas or charcoal. Slower and less controllable, but most households already own one.
4. A slow cooker on a battery. The one efficient electric route, and it runs unattended.
5. A kettle or microwave on a battery, in bursts. Hot drinks and reheating, which after two cold days matters more than it should.
6. Food that needs no cooking. The plan that never fails.
Cook the fridge first
A sequencing point that saves real food and is rarely mentioned.
USDA guidance is that a refrigerator keeps food safe for about four hours and a full freezer for about 48. So the order to eat in is:
- Fridge food first, on day one, while it is still clearly safe.
- Freezer food next, as it thaws, over days one and two.
- Shelf-stable food last, because it will keep indefinitely.
Most people do the opposite — open a tin because it is easy — and then throw away a fridge full of food. Cooking the perishables on day one is the single most valuable cooking decision in an outage.
The freezer page covers the temperature rule for what is still safe afterwards.
Practical points people learn the hard way
- Cooking needs water. Boiling, washing pans, washing hands. Factor it into water storage rather than counting only drinking water.
- Cook once, eat twice. Fuel and water are both finite; one pot that does two meals halves both.
- Disposable plates are not wasteful in an outage, they are water conservation.
- A pot with a lid uses far less fuel than one without.
- Keep a manual can opener. Every list includes it and every household discovers they only own an electric one.
- Store more cylinders than you think. They are cheap, they never go stale, and running out mid-week is avoidable.
- Set the stove up somewhere sheltered but genuinely open — a patio, not a garage with the door up, and not under a low awning.
The winter version is harder
Cooking outdoors in a snowstorm is genuinely unpleasant, which is precisely why winter is when people bring stoves inside.
The realistic answers:
- Cook less, and cook simply. Hot water for drinks and instant food beats a proper meal you have to stand outside for.
- Use the battery for the small electric jobs — kettle, microwave, slow cooker — because those are indoor-safe and the arithmetic works.
- Set up in a sheltered spot and cook in one session rather than three.
- A vacuum flask is genuinely useful. Boil once outdoors, have hot water for hours indoors.
What is not an answer is bringing the stove in. The winter kit covers the rest of the season, and the alarm is the backstop for the moment somebody does it anyway.
