Electric Blanket Draw?

[wa8yxm]

As others have said, Check the label. Which of course will tell you nothing useful unless you know how to do the math.

Watts/10 = approximate DC current draw

AMPS*11 will be about right

Both lines are a bit "Fudged" to take into account inverter efficiency and such but they be very close I suspect the 2nd is the closest. but they will both be close.

[Triker56]

Winter!! It is 98º and feels like 107º outside here right now.
A electric mattress pad or electric blanket use is several months away.

[wa8yxm]

One comment.. Several folks have reported "Issues" using an electric blanket with an MSW inverter like the Xanterx X-power. Use it with a true sine wave, like a Xantrex Prosine, no such issues. Depends on the blanket too I suspect.

What kind of issues. .Failure of the blanket control unit up to and inlcudind escape of the magic smoke, and as you know when the magic smoke escapes, the device no longer functions.

The conversion factors I use in the earlier post.. Apply to both TSW and MSW, not a lot of difference in efficiency.

[Senior Chief]

A low tech method for a warm bed in a cold climate is to fill a hot water jug or 2 and place it under the covers 20 minutes before retiring. Once the bed is warmed up, body heat will keep it comfortable.

If you don't like a down or down-equivalent, use multiple light weight thermal-type or polar fleece blankets; more effective than heavy quilts.

Use of Mylar emergency blankets under the bottom sheet or sandwiched between blankets on top and stay toasty in (literally) sub-zero temperatures.

Wear fluffy socks to bed if your feet get cold (poor circulation in the feet is the most common reason people feel cold in bed).

If the wall by the head or side of the bed "leaks" cold, put a thin sheet of styrofoam on the wall and cover it with a pretty coordinating fabric.

We lived on an off-grid ranch for many years, and heated solely with wood. Bedrooms were NEVER warm in the winter.

[Shadowcatche]

There are any number of 12V electric blanket/mattress pads available. I have adapted a Eberspacher D2 diesel heater to use with our Teardrop trailer very low amp draw for the heat.

[WarmBedGuy]

Originally Posted by ralper

My queen sized dual control mattress pad heater draws 70 watts total @ 120 volts. This is .583 Amps. Due to the electronic control it will not work on my modified sine wave inverter. Bear in mind that it will not draw this constantly and will go off and on with the thermostat.

You are correct about the cycling on and cycling off greatly reducing your current draw compared to the rating tag. You can verify this by using a Kill-A-Watt recording device as someone has suggested in this thread. You may also be interested in reading our Electric Blanket Institute Consumer Guide page on the actual cost of running a heated blanket or mattress pad. Actual Cost of Running an Electric Blanket or Electric Mattress Pad.

Regarding wa8yxm's comments about full wave and modified wave inverters, we have found in our testing at the Institute that only one brand of electric blanket (or electric mattress pad or throw) will work consistently with MSW inverters. We've had so many questions from readers about this that we wrote an article on it which you can read at Heated Electric Blankets with Inverters.

Best regards,

[wa8yxm]

Warm Bed Guy.. I knew SOME brands had isssues with MSW.. I did not know that "Some" was defined by the formula N-1 ( Where N is the total number of brands tested)

WOW. That is worse than I thought. Guess I'd better change "Some" to "most"

Oh and thanks for the reference.

[jackfish]

I know this is an old thread but if a 115v AC mattress pad uses a maximum of 1 amp how much would that draw from a 12 volt system with a 2000 watt inverter?

From the ElectroWarmth website: http://electrowarmth.com/guarantee
The rated volts, amps, and watts are shown in the table below.
The 12 volt Comfort Control thermostat cycles the warmth on & off at short intervals. It pulls full rated amperage only when cycled on. The amount of time it is cycled on versus off depends on the Comfort Control setting. Experience has shown that on average, it is cycled on less than 50% of the time. Since the rated amperage listed is maximum if it is on 100% of the time, the average load on the battery system is 50% or less of the rated amperage (reports of battery problems have been negligible in the 40 years we have made the 12 volt products).
Cord length is 3 feet 6 inches from warmer to Comfort Control and 6 feet 8 inches from control to electrical plug.
The 115 volt Comfort Control features quick warm-up on all settings, which include L for low, 2-9, and H for high. Depending on the setting you select, the control runs at maximum output for a period of time to quickly warm the bed. The automatic shut off feature gives you ten hours of continuous use before shutting off.

115 V Model Bed Warmers
RatedMaximumModel NumberVoltsWattsAmps.M30FL,M30FXL
115
55
0.5
M38F, M38FL, M38FXL
115
69
0.6
M54F, M54FL, M54FXL
115
111
1.0
M60F, M60FL, M66FL
115
99
1.0
M54FD, M54FLD
115
111
1.0
M60FD, M60FLD, M60FXLD, M66FLD
115
112
1.0
M72FXLD
115
133
1.2
M76FLD, M76FXLD
115
133
1.2

Cord length is 12 feet from warmer to Comfort Control, 6 feet 8 inches from control to electrical plug.

12 V Model Bed Warmers
RatedMaximumModel NumberVoltsWattsAmps.T36
12
75
6.3


Cord length is 3 feet 6 inches from warmer to Comfort Control and 6 feet 8 inches from control to electrical plug. (Our 12 volt units are not UL approved).

[DAN L]

Originally Posted by jackfish

I know this is an old thread but if a 115v AC mattress pad uses a maximum of 1 amp how much would that draw from a 12 volt system with a 2000 watt inverter?

From the ElectroWarmth website: Guarantee: Heated Mattress Pad | Bed Warmer | Made in USA
The rated volts, amps, and watts are shown in the table below.
The 12 volt Comfort Control thermostat cycles the warmth on & off at short intervals. It pulls full rated amperage only when cycled on. The amount of time it is cycled on versus off depends on the Comfort Control setting. Experience has shown that on average, it is cycled on less than 50% of the time. Since the rated amperage listed is maximum if it is on 100% of the time, the average load on the battery system is 50% or less of the rated amperage (reports of battery problems have been negligible in the 40 years we have made the 12 volt products).
Cord length is 3 feet 6 inches from warmer to Comfort Control and 6 feet 8 inches from control to electrical plug.
The 115 volt Comfort Control features quick warm-up on all settings, which include L for low, 2-9, and H for high. Depending on the setting you select, the control runs at maximum output for a period of time to quickly warm the bed. The automatic shut off feature gives you ten hours of continuous use before shutting off.

115 V Model Bed Warmers
RatedMaximumModel NumberVoltsWattsAmps.M30FL,M30FXL
115
55
0.5
M38F, M38FL, M38FXL
115
69
0.6
M54F, M54FL, M54FXL
115
111
1.0
M60F, M60FL, M66FL
115
99
1.0
M54FD, M54FLD
115
111
1.0
M60FD, M60FLD, M60FXLD, M66FLD
115
112
1.0
M72FXLD
115
133
1.2
M76FLD, M76FXLD
115
133
1.2

Cord length is 12 feet from warmer to Comfort Control, 6 feet 8 inches from control to electrical plug.

12 V Model Bed Warmers
RatedMaximumModel NumberVoltsWattsAmps.T36
12
75
6.3


Cord length is 3 feet 6 inches from warmer to Comfort Control and 6 feet 8 inches from control to electrical plug. (Our 12 volt units are not UL approved).

the electronic electric blanket control requires a full sine wave inverter.
due to electrical losses, the conversion factor, ac to dc, is 10:1, not 12:1.
according to their website, they have a 12v warmer that draws 6.3 amps.

this info may help.

Ohm's Law - The basics - Ohms Law Formulas Explained to save you time

[vsheetz]

Get a good down comforter instead. Works great. No electric needed.

[nuttcaze]

i bought a 12v electric blanket off of Amazon before this past winter for only $20 and it has a built in timer that turns it off in either 30 or 45 mins depending on what you set the switch too. very handy for anyone needing an electric blanket

here is the one I bought, though it has gone up in price a few $'s - Amazon.com: Heated Fleece Travel Electric Blanket - 12 Volt - Red Plaid: Automotive

[J Birder]

Originally Posted by vermilye

Before you plan on using an electric blanket with an inverter, check that it will work at all. Many of the controllers don't like the output of modified sine wave inverters.

Most modern electric blankets use an electronic, digital control, and will not work with a modified sine wave inverter. Older blankets with analog controls will work with a modified sine wave inverter, but are very hard to find.

The Soft Heat blanket from Perfect Fit comes a power supply and actually uses 18 vdc at the blanket. It will work with a modified sine wave inverter. It is a little more expensive than most other blankets, but is so much nicer that I got a second one for my S&B house.

See Best Electric Blankets Reviews | Review Soft Heat Low Voltage

Joel