What it draws
Space Heater
Every so often somebody asks whether a power station can run a space heater through a cold outage. The arithmetic answers this before any safety consideration does, and the answer is not close. Heat is the most expensive thing electricity does.
Typical draw, and the number that actually applies
A household electric space heater commonly draws between 750 and 1500 W, and most run at 1500 W on the high setting. Unlike most loads on this site, a heater draws its full rating the entire time it is on.
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
- 1500 W
- Duty share applied
- Continuous
- Average draw for the estimate
- 1500 W
Hours from a 1024 Wh battery
Estimated hours from the reference battery at 1500 W average draw. An estimate, not a guarantee.
The arithmetic, in full
hours = (rated Wh x 0.85) / average watts
average watts = 1500 W running x 1, continuous = 1500 W
= (1024 x 0.85) / 1500 W = 870 Wh / 1500 W
The estimate below is shown in hours for consistency with the other device pages, and the result speaks for itself. A heater at this draw also exceeds the stated continuous output of every unit in this catalog except the largest, which would refuse it and leave you with nothing.
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.
- Close off one room and gather everyone in it. A smaller volume of air is the cheapest heating decision available.
- Layer clothing and use blankets and sleeping bags. Insulation on a person costs nothing and works while you sleep.
- Block drafts at doors and windows with towels, and close curtains after dark to slow heat loss through glass.
- If the house is genuinely getting too cold, leave for a warming center, a relative, or a hotel. That decision belongs to a plan made in advance, not to a battery.
Where this sits in the sequence
No stage in this sequence covers this load
- No stage in this sequence covers running a space heater from a portable battery. Resistive heating converts the entire reserve into a short period of warmth, and the load exceeds what nearly every unit here states it can supply.
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.