12V heater run straight from solar panel

[DarkSkySeeker]

Is there a heater product that can run off the 12V that comes directly off my portable solar panel? This would have to be something that can handle unregulated power that might peak up during bright sun and drop very low when a cloud passes by.

[pauldub]

See if you're satisfied with the heat you can get from a 100W light bulb. If you're not satisfied with that, then you're not going to be satisfied with the heat you can get using a solar panel.

[DarkSkySeeker]

mich800 wrote:
Are you trying to heat an RV, are you just trying to not use batteries until night?

Seems like it would be more efficient to have all the panels charging the battery bank and just using the furnace. Just curious on what you are trying to achieve.

I am thinking that in the early morning, when the sun rises, it might be nice to have "free" warming of a room in my house (to be honest) using my solar panels and some resistors.

[mich800]

ooops. delete

[mich800]

Are you trying to heat an RV, are you just trying to not use batteries until night?

Seems like it would be more efficient to have all the panels charging the battery bank and just using the furnace. Just curious on what you are trying to achieve.

[red31]

Vmp/Imp would be the R for spec'd mppt.
add a 12v computer fan to move heat away from R!

[B_O__Plenty]

A 1500 watt heater will produce 5,280 BTUs of heat. Going to need a lot of solar and small electric heaters to get to this point.
B.O.

[wa8yxm]

There are 12 volt defroster heater/fans you can get in auto stores run around 100 watts. not much heat and basically not worth the time. also you would need a whole lot of solar and battery to run one.. Good for defrosting the windshield however but even there... YOu need more than solar.

[pnichols]

DarkSkySeeker wrote:
Is there a heater product that can run off the 12V that comes directly off my portable solar panel? This would have to be something that can handle unregulated power that might peak up during bright sun and drop very low when a cloud passes by.

You might want to locate and buy one or more of these 120V 155 watt "personal heaters" that can keep one person per heater toasty if it's close to them and aimed right at them.

It has 3 settings - one fan-only setting for cooling and low and high heat settings. It consumes about 155 watts on it's high heat setting. We use a couple of them at home to warm us when sitting so we don't need to have the house furnace set so high. On RV trips I take both of them along for emergency heat boosting in specific areas of the coach when on hookups.

I have run one all night off a 300 watt pure sine wave inverter - fed by one Group 31 12V AGM battery - to heat the interior of my truck when sleeping in it overnight at a remote campsite. The two I have are several years old and have been super reliable.

https://www.ebay.com/p/1524623641?iid=274188423300

[DarkSkySeeker]

time2roll wrote:
You will be lucky to keep the 12v battery charged and burn propane running the furnace.

My idea is to run the heater directly from stand-alone solar panel(s), not via the RV batts.

[Flute_Man]

DarkSkySeeker wrote:

Flute Man wrote:
I have a 12 V 300 W heater in my rally compartment. It draws 25 A so figure yours accordingly.
Electric heaters have a very simple formula.
Watts Divided by volts equals amps.

Did you buy it online? If so, could you share the link?

It came with my motorHome. Sorry

[wopachop]

Some people use little 12v automotive bulbs to drain lipo batteries used for RC toys. One guy had quite a few on a board and said it put out a lot of heat.

I think what you propose will work to some degree. Maybe you can set a chair over your heat device. Like when someone puts a few campfire coals under a chair.

[2oldman]

DarkSkySeeker wrote:
Is there a heater product that can run off the 12V that comes directly off my portable solar panel? .

One panel? You'd be lucky to heat an ant farm.

[DrewE]

DarkSkySeeker wrote:
What if I bought 5 of these, wired them in parallel, and mounted them on a board?

PRODUCT LINK

At 12V, Ohm's law says that 1.2A would flow through each one, which means a dissipation of a bit under 15W each. Total wattage would be around 150W. To get 50W power dissipation, the applied voltage would have to be a bit over 22V.

According to the resistor data sheet, with no heat sink (i.e. mounted on a board), rated dissipation is 14W. To dissipate 50W each you must have a heat sink to keep their temperature reasonable. In either case they ought to be mounted on something that can take the heat; a wooden board would not be the wisest choice in my estimation.

$35 seems like a lot of money to spend for the anemic results you'd tend to get.

[Lwiddis]

25 amps? That’ll drain a battery. Or require five 100 solar watt panels producing at almost max.