small elec/ceramic htr/solar?

Don't confuse peak draw and total draw

That mattress pad is not going to run at full draw continuously, unless you are sleeping on bare steel van floor

When on your bed aka mattress, it is going to draw what is need to keep the bed at the temp you set So it cycles on off,

our bed set over the engine, lots of cold air under there
we ran a mattress pad or electric blanket on the bed in the Safari, we had four batteries and a residential fridge, and no problems with overnight power, of course I'm not in the north east

Changed MHs , don't need the mattress heater so much now

Big power users- microwave, electric heaters, toaster and AC.

time2roll wrote:
Overnight an electric mattress pad and a thicker blanket will give far more comfort.

While I agree that heated mattress pads do give nice warmth, better than an electric blanket, but a queen pad can draw 200 watts ! With a 90% efficient inverter and 8 hours you will need about 1800 watt-hours or energy. That should be about 150Ah on a 12V supply.

My 12 volt dc heating blanket works well. It draws 6 amps and does eventually start to cycle. I wish I could find a mattress pad as that would be even better.

If you wish to power a heater during "solar noon" you may run a 300 watt heater for about 90 minutes before and 90 minutes after. However, that may mean there is not enough sunlight left to return the AGM to fully charged.

If you had a firefly battery bank fully recharging needs not be done every day--but should be done once per month (or more often).

Has anyone simply connected their panels directly to a dc heater?

there is a 12v heated mattress pad i use that works well does draw 6 amp max when on but it cycles on and off so its not a continues draw.
electrowarmth
amazon price

Ok, most of those small Ceramic heaters are dual wattage 750/1500

FOr ease of math divide by 10 volts. Power factor on these puppies approaches 1.0 (1.0 is by the way ideal) so we can forget power factor and just say 75 amps or 150 amps will be drawn off the batteries. Now the 255 amp hours you cited (What size battery is this or do you have multiple) is the 20 hour rate (or the wal_mart rate which is even worse) so at 150 amps.. I'd be surprised if the batteries lasted 5-10 minutes. at half power perhaps 10 minutes.. You need a LOT more battery and a LOT more solar to even think about it .

Not to mention more than one RVer had burned up his/her 120 volt wires using a space heater.

Measured single mattress heating full size pad. Ninety+ watts. 50F night. Heat is on 5.4 out of 8 hours, using a comforter.

More than 40 amp hours...

This means a lot of fuel expended or an airfield landing strip's worth of solar panels in deep overcast winter usage. It was right after putting up with gen run time for a mattress pad that I purchased a Wave 8.

I remember 60 years ago my Aunt in Seattle explaining her electricity cost was less than 2 cents per kilowatt hour. It was so cheap her house was uninsulated.

Hard to get electrical specs for mattress pads on-line. Browse Kohl's etc in person might be best. I recommend one with a brick that provides low voltage to the controller. They may all be this way now. Need the wattage rating to select an inverter. Need a small sine wave inverter to drive the pad. Maybe you already have one.

Yes I believe this will work for you.

SidecarFlip wrote:

GordonThree wrote:
Use the Sun itself to take the chill off, it's more efficient than converting the Sun's heat to electricity and then back into heat. move the panels out of the way, paint the roof flat black, insulate the windows, plug any outdoor air leaks, and park in the Sun.

Nothing like a sane answer to an insane question....lol

Make sure you turn on your headlights when you park in the sun at night, the sun is hard to see at that hour.

A standard RV furnace does not add moisture to the inside air, since the combustion chamber is sealed from the inside air (and vents to and from the outside). An unvented heater will add moisture to the inside air, potentially quite a bit of moisture.