12V heater run straight from solar panel

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.

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.

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.

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

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

There are a lot of 12v heaters on Amazon and Ebay.
Those 12v heaters are real power hogs. You would need a minimum 400 watts of solar to run a 300 watt heater. Which would put out very little heat in a large space.

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?

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.

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

PRODUCT LINK

DrewE wrote:
A big resistor that can dissipate a lot of power at 12V, sufficient to be a useful heater, is also a low-valued resistor, on the order of one ohm (approximately 150 watts). Making your own with resistance wire would probably be easier and less expensive than finding and affording a commercially produced resistor, marketed as such. Having a few coils wired in parallel is probably a good idea, too.

I'd think, for heating with solar power, that a solar water heater (as in a black pipe in a reflective trough or something similar) and a radiator of some sort would be more efficient and effective overall. The cost would probably be lower, too.

Agreed. My basic motivations are like this: I have these solar panels and what if I used them to generate ~500W continuously? And to avoid the complexity of a water heater based system, I wanted to be able to attach the 1 ohm resister(s) to create passive and unregulated heat.