Using 120v electric blanket on inverter

[Maggie]

Has anyone used a 120v heating blanket with inverter on solar? I have a short twin heating blanket that is 120v that has no amp/watt  information on the unit. I'm wondering if I can test it with a multimeter to see how much it uses? It works great on shore power, I turn on 30 minutes before getting in bed and then turn off once in bed because I get too hot. I use it layered between a thin bedcover and a top heavier bed cover.

 

[Almost There]

You'd likely be better off investing in a 12V mattress pad than using 120V blanket and inverter.

The mattress pad warms from below so it's actually more efficient in heating the bed. They've been made for the trucking industry for years now. Best place to get them might be a truck stop.

You can test the heating blanket with a Kilowatt meter to find out how much power it uses in a defined period of time. A multimeter won't tell you this, it measures current.

Don't forget to figure in the inherent power use of the inverter that you are using as well.

 

[tx2sturgis]

This can work well IF you have enough reserve capacity in the battery bank, but a much better solution is to buy a 12v mattress pad heater. Then you dont need the inverter at all.

These can run all night on low and provide plenty of warmth and they don't kill your batteries, but you will need enough solar input the following day to recharge the batteries.

 

[hugemoth]

Many electric blanket controllers use SCRs in the circuit which don't get along with modified sine wave inverters. There is a chance that the magic smoke will come out and the blanket won't heat.

 

[LoupGarou]

You can certainly use a multimeter to measure the current. The easiest way is to get yourself a Kill-A-Watt Meter.

I prefer a heated mattress pad over a blanket. The Sunbeam Style P85A, using the Kill-A-Watt meter, pulls 2.5 amps when it cycles. I keep it on all night and let it cycle as it needs too. It runs off a Goal Zero Yeti.

 

[Weight]

Yes. But to use a multimeter to measure the current you have to splice it into one side of the 120 volt cord. That can get interesting if you are not experienced. You could measure the resistance of the blanket circuit and use math to get a close estimate. Or for less than $15 get a Kil-A Watt meter. Then you can also test many other items for your general knowledge base.

 

[AJ452]

If you're using a clamp style meter to measure 120v current you can avoid messing with wires by using a line splitter.

https://www.amazon.com/Line-Splitter-Klein-Tools-69409/dp/B01B7RTNSO/

Kill-A-Watt's are certainly handy as well.

 

[John61CT]

Go direct 12V.

Any use case producing heat from battery energy is at least suspect if not foolish IMO

much better for example to use a water bottle heated with your propane cookstove.

 

[tx2sturgis]

Just for grins I measured the 120v twin-size mattress pad I use, and it registers about 55 watts when it cycles ON and about 0.3 watts when it cycles off. (I would assume an electric blanket would double this power drain, but I dont own one to be able to verify this.)

Interestingly, the label on the heat controller has '180 watts' printed on it. 

I tend to run mine on the medium settings and there is a thin foam pad above it. It's comfy for me that way.

Some light math (and rounding off)....

Assuming 50% duty cycle all night, for let's say, 8 hours;

220 watt-hours for one night of use. (55x4) Add 1 watt-hour for the standby use.

On solar, with a pure sine inverter at 80% efficiency, call it 265 watt-hours. (221 + 20%)

A few hours of strong solar input the next day on 200 watts of panels should easily recover this, but also needs to power whatever else is running: fridge, laptop, lights, etc.

Again, an electic blanket draws more power than a heated mattress pad, in normal use. 

The problem is that for the price of buying a new inverter and providing extra battery power and solar, and maybe a meter or kill-a-watt to measure everything, you could just buy a 12v bunk heater (heated mattress pad) and be done with it. 

If you are aready using an inverter, and have the meter and extra solar capacity, then yes, it can work...

 

[highdesertranger]

I would try to go 12v native. the more conversions = more power wasted. highdesertranger

 

[maki2]

electric blanket versus heated mattress pad.

Heat rises, if you have an electric blanket much of the heat goes up into the air. It is not safe to put another blanket over the top of an electric blanket, they are not designed for that and it can cause a fire. You can't sleep on top of an electric blanket, the are not designed for that, it can create a fire.

heated mattress pad, heat rises, it warms your body. It is designed to be laid on top of. You can put another blanket on top of you to capture the heat produced by the mattress pad. That means you don't need to use nearly as much electrical power to stay warm as you would with an electric blanket.

The choice of what you should get is obvious. Even if you buy a 110 electric mattress pad it is still the better choice for power conservation than using a 110 electric blanket. The biggest advantage is putting blankets on top of you to help retain your body heat and the heat produced by the mattress pad. But you can stay just as warm if you invest that outlay for an electric mattress pad into a good quality goose down comforter or sleeping bag and you won't have to use any electricity to get warm. Of course your bed won't be pre-warmed when you get into it but it won't take very long before you are warm and cozy inside your nest.

 

[frater secessus]

While heat does rise, I suspect the superiority of the pads over blankets is due to proximity; one is pressed by gravity into the pad.

 

[Homeless in Canada]

You don't need a kill-o-watt meter. Those are useful for measuring the daily power consumption of appliances that cycle on and off like refrigerators. You can measure how many amps the blanket draws with a multimeter which is far more useful tool to have on the road imo.

Since I'm not a pro I plugged the heater I was testing into a power bar, then inserted the test prongs into an empty socket on the power bar, and plugged the power bar into the household outlet last so I wouldn't get a shock from inserting the prongs into a live outlet.

 

[highdesertranger]

Homeless I don't understand how you are doing that? and wouldn't you need a meter that reads AC. highdesertranger

 

[B and C]

All I can see is you could measure volts this way, not amp or watts. I must be missing something.

 

[Manyways2go]

I must be tired none of this makes sense to me, power bar test on what scale? not live current?

 

[Seminole Wind]

electric blanket versus heated mattress pad.

Heat rises, if you have an electric blanket much of the heat goes up into the air.

that (heat rises) is a misconception. "heat" travels in all directions equally. sure hot AIR will rise, but that is because as air warms it expands and becomes less dense, thus it "floats" and rises above the cooler denser air around it. but "heat" it's self does not rise. in this case an electric blanket tha you cant put another blanket over will lose some heat to the air above it, but not all

You don't need a kill-o-watt meter. Those are useful for measuring the daily power consumption of appliances that cycle on and off like refrigerators. You can measure how many amps the blanket draws with a multimeter which is far more useful tool to have on the road imo.

Since I'm not a pro I plugged the heater I was testing into a power bar, then inserted the test prongs into an empty socket on the power bar, and plugged the power bar into the household outlet last so I wouldn't get a shock from inserting the prongs into a live outlet.

that could only test the voltage, which tells you nothing about the energy consumed. in order to measure watts or amps most multimeters (other than "clamp: style) require an inline or series connection
in order to measure amps ( from which you can calculate watts if you know the volts at the time of measurement)

 

[LoupGarou]

A Kill-O-Watt meter is certainly useful for measuring the daily power consumption of appliances that cycle on and off like heated mattress pads and blankets.

 

[Riverman]

You can not measure watts or amps with a multimeter,

You can measure volts.

A multimeter will not tell you anything about power consumed.

You need a kill o watt meter (Harbor Freight Tools) to see hot many watts you are using.

 

[highdesertranger]

"You can not measure watts or amps with a multimeter,"

sure you can, with the right meter. but you are correct that most but not all will give you the amount consumed over time. I have a Fluke that will measure Amps on AC or DC up to 999 Amps but it will not do a 24 hour reading. highdesertranger