Electric Blanket Power Station Calculator

A household AC electric blanket draws only a modest wattage — examples run from tens of watts to well over 100 W depending on size, controller, and model — so it is easy to assume a small power station will run one. Wattage is rarely the sticking point; the runtime is. A full night is 6 to 10 hours, and a small load held that long adds up to a meaningful number of watt-hours.

At 75 W for 8 hours that is 600 Wh of raw energy, and after inverter losses and a reserve the recommended battery capacity is closer to 900 Wh — enough that a 500 Wh unit falls short for a whole night. The AC-output requirement stays at 75 W the entire time, which the listed power stations comfortably supply.

So for an electric blanket, battery capacity and runtime are the binding electrical constraint, not the inverter rating — the opposite of a kettle or a heater, where a brief high draw makes AC output the limit. One thing capacity does not settle: some heated blanket manuals prohibit inverter or generator power outright, so confirm your blanket permits power-station use before relying on any of this.

The energy side of this uses the same method as the main Power Station Size Calculator. Two specifications decide whether a power station can run an electric blanket, and they are independent:

• Battery capacity, in watt-hours (Wh), is the stored energy. For a blanket this is the number that matters: a low draw over a full night is several hundred watt-hours, sometimes more than a kilowatt-hour on a high setting.
• AC output, in watts (W), is how much power the inverter can deliver at once. A blanket's draw — typically tens of watts, sometimes over 100 W — sits inside the listed power stations' inverters, so among those units AC output is usually not the limiting specification. Manufacturer compatibility still has to be checked separately.

The practical electrical question is whether the battery lasts until you wake up. To check how long a given unit runs a steady low load, use the Power Station Runtime Calculator. Sizing does not replace the blanket manual: some heated bedding is not rated for inverter or generator power at all.

• Rating label. Check the blanket's care label, the controller, and the plug pack. It usually lists volts and watts, or amps (amps × volts = watts). Dual-control blankets may list each side separately.
• Manual or manufacturer spec. Look for “rated power”, “wattage”, or a figure per heat setting.
• Watt meter. Plug the blanket in and read the wattage while it is actively heating — that active draw is what you enter, and what the inverter has to supply. A meter also shows the lower long-run average once the thermostat starts cycling, which is useful for a separate energy estimate but is not the figure for this calculator.

As a rough guide only, small heated throws tend to be at the low end and large dual-control blankets on high draw the most, and figures can range from tens of watts to well over 100 W depending on size, controller, and model. These are search-intent examples, not a rule — do not assume a figure from the blanket size. Read the label or manual and enter the exact number for the setting you use.

Energy use is the active watts multiplied by the hours it runs. The wattages are small, but a full night is long, so the totals reach a few hundred watt-hours. These are a planning ceiling — a blanket whose thermostat cycles a lot will use less over the night.

Electric blankets have Low, Medium, and High settings, and most have a thermostat in the controller that switches the heating wires on and off to hold a temperature. Neither behaviour is fixed enough to model:

• The relationship between the setting and the power draw is set by the manufacturer and is not a clean percentage — there is no reliable “Low = 30%” or “High = 100%”.
• Once the blanket is warm, the thermostat cycles the element, so the average power over a night is often below the active draw. How much below depends on the room temperature, the bedding, and the setting.

So the calculator does not convert a setting into a wattage or apply a duty-cycle discount. Enter the active input watts at the setting you plan to use — the draw while the element is heating, from the label or a watt meter — and otherwise the nameplate maximum as a conservative planning value.

The calculator uses the watts you enter for two things at once: the battery-capacity estimate and the required AC output. That is why the figure to enter is the active or rated heating draw — the power while the element is on — not a long-run average.

A blanket with a 75 W active draw might average only 45 W over a night once the thermostat is cycling. If you entered 45 W, the energy estimate would look more realistic, but the required AC output would drop to 45 W too — and the inverter still has to supply the full 75 W whenever the element switches back on. Do not put a cycling average in the watts field.

If you have measured your blanket — a total watt-hour reading over a night, or an average wattage — you can use that for a tighter capacity estimate on its own: multiply the measured average by the hours, or take the measured watt-hours directly. Then still check the power station's AC output against the blanket's full active or nameplate wattage separately. For a capacity estimate built from several figures, add them as rows in the main Power Station Size Calculator — and check the output against the full wattage yourself. The Power Station Runtime Calculator shows how a steady low draw pulls a battery down over a night.

Many electric blankets and heated throws switch themselves off after a set period — often somewhere between 1 and 12 hours, depending on the model and the setting. Some cannot be overridden.

The calculator does not assume a shutoff time. Enter the hours you actually expect the blanket to be drawing power. If your controller shuts off after, say, 8 hours and you go to bed for 9, the blanket is only a load for those 8 hours — enter 8, not 9. If you plan to restart it, add the extra powered time.

Check your own blanket's manual for its timer behaviour rather than assuming a common value, and treat the shutoff as a safety feature to keep, not an inconvenience to work around.

This calculator models a household AC electric blanket: it applies an inverter-efficiency factor because the power station has to convert DC battery power to AC, and it reports a required AC output. Low-voltage heated blankets do not run through the inverter, so that model does not apply to them:

• 12V heated blankets plug into a car-style socket or the power station's DC output and bypass the AC inverter. They tend to be in the low tens of watts.
• USB heated blankets and throws run from a USB-A or USB-C port at a handful of watts and are really a warm accessory rather than a bed heater.

12V and USB heated blankets are outside this calculator's AC model. Size them from their actual source-side energy use — the DC watts they draw times the hours — and account for any DC-conversion losses the device or power source specifies. Do not carry the AC calculator's result, including its required AC output, across to a 12V or USB blanket. As with an AC model, check the manufacturer's manual for permitted power sources.

On the electrical side, for a few hours — a heated blanket is one of the lighter heating loads a 500 Wh unit can take on. With this page's default 85% inverter efficiency and 20% reserve, a 500 Wh nameplate battery corresponds to roughly 340 Wh of planned load-side energy. A low-wattage throw run for an evening fits inside that; a mid-wattage blanket for a full night does not.

A full night is a different story. A 75 W blanket for 8 hours is 600 Wh raw, already past what a 500 Wh unit plans for, and a higher-wattage dual-control blanket runs it down in a few hours. Among the listed power stations the inverter is usually not the limit for a low-watt blanket — it comes down to whether the battery holds enough watt-hours for your run time. This is electrical sizing only: it does not mean your blanket manufacturer permits inverter or power-station use, which the manual has to confirm.

On the electrical side, usually yes for one blanket. With this page's default 85% inverter efficiency and 20% reserve, a 1,000 Wh nameplate battery corresponds to about 680 Wh of planned load-side energy. A 75 W blanket for an 8-hour night is 600 Wh raw and about 882 Wh recommended once losses and the reserve are added — near the edge of a 1,000 Wh unit, so it works with little margin. A lower setting or a smaller blanket leaves more headroom; a higher-wattage blanket on high may not last the night.

Thermostat cycling often means the real overnight draw is lower than the planning figure, which buys back some margin — but size for the active wattage first. This is electrical sizing only; the blanket manual still has to permit inverter or power-station use. If you also want to keep a CPAP, phone, or light going through the night, add them together in the Home Power Outage Calculator, or check a single overnight load in the CPAP Power Station Calculator.

• Camping. A heated blanket usually uses far less power than heating a whole tent or cabin with a space heater, because it warms the person and bedding directly — often tens of watts rather than over a thousand. A 12V blanket is the lightest option off-grid because it bypasses the inverter. The Camping Power Station Calculator sizes it alongside the rest of your gear.
• RV. A blanket's draw is small next to an RV inverter's rating; the electrical question is how many amp-hours of the house bank a full night uses, especially on several cold nights between charges. Check the blanket manual permits inverter power. The RV Power Station Calculator covers 12V and AC loads together.

A blanket pairs naturally with other quiet overnight loads. A CPAP is a similar few-hundred-watt-hour job, and a slow cooker is the daytime version of the same trade — low watts, long hours, capacity-limited rather than output-limited.

In a winter outage, a heated blanket usually uses far less power than heating a whole room with a space heater, because it warms the person and bedding directly. A space heater can pull well over a thousand watts and drain a portable unit in under an hour; a blanket drawing tens of watts can keep a person warm for a whole night on a small share of the same battery. Check the blanket manual allows inverter or power-station use first.

For an outage, that usually means:

• Back up essentials first — medical equipment, the refrigerator, lighting, communication — and size those with the Home Power Outage Calculator.
• Plan the blanket as an overnight energy load: active watts times the hours, checked against what you can spare after the essentials.
• Warm the bed, then drop to a lower setting or let the timer take over — heating to temperature costs more than holding it.

Check every item against your blanket and your situation before buying or using one:

• Manufacturer explicitly permits it. The blanket manual allows inverter, generator, or portable-power-station use. If it prohibits any of those, do not run the blanket from the power station's AC outlet.
• Required waveform / AC source requirements — if the manual specifies pure sine wave or any other AC source condition, the power station meets it. A pure sine wave output does not by itself make the blanket compatible.
• Voltage and frequency match the blanket — typically 120V / 60 Hz for a North American mains model, or the correct DC output for a 12V or USB one.
• Actual blanket active or rated watts from the label, controller, or a watt meter — the heating draw, not a cycling average.
• Required runtime in hours, allowing for the controller's auto-shutoff timer.
• Battery capacity (Wh) at least the recommended figure from the calculator — the number that actually decides this.
• AC output (W) at or above the blanket's active watts. Among the listed units this is usually not the limiting spec, but confirm it.
• Outlet or adapter compatibility for the blanket's plug or DC connector.
• Controller and blanket instructions read in full, and no damaged cord, connector, or controller in use.
• Automatic shutoff behaviour from the manual, kept as a safety feature.
• Recharge time from wall, vehicle, or solar, so the unit is ready for the next night.

For an electric blanket, a power station in the right range is mostly a question of usable watt-hours for your run time. Confirm the unit's real usable capacity, and follow the blanket manufacturer's instructions — this page sizes energy, not safety, and does not establish that a given blanket may be run from an inverter.