heat from a 12 Volt battery

[Geospar]

Is it possible to have a thin heating element like a silicone/rubber pad, a foil, a wire or a wrap that would cover an area 4 x 6 inches long, heats to 120 + degrees, can run off of a small battery (12V or less) and last at least 30 min? Is the technology out there or would you have to change it to a greater power source like 120V to achieve this? The answer I have received from my research so far is that it would take 150W of power to heat something this size to 120-130 degrees F and require a large 12V battery with min 10AH to last 20 min. Is this the best solution? Chemical heating pads are too thick but achieve the right temperature and for safety it has to be low voltage. Any ideas?

 

[jpanhalt]

Sure, just put the whole thing in a vacuum. Won't require much power at all.

Realistically, you have not mentioned anything about the ambient conditions or how fast heat will be conducted away from this heating pad. If your assumption of 150 W is accurate, new technology won't change that number. You can get it from electricity, chemical reaction (including catalytic oxidation and burning), or mechanically.

John

 

[Geospar]

Heat from 12V battery.

OK, so since this device would not operate in outerspace and be at room temp of 70 degrees F, the transfer of heat from the element at 120 deg. F to the 70 deg. F material could be calculated I suppose...but not by me. Can you think of any specific heating element out there that could operate off of a smaller battery from 12V 1000 mAH up to 12V 5AH to fulfill the requirements?

Geo.

 

[jpanhalt]

The answer I have received from my research so far is that it would take 150W of power to heat something this size to 120-130 degrees F and require a large 12V battery with min 10AH to last 20 min. Is this the best solution?

Maybe I should have used a smiley after the first sentence.

You have already given the answer. You need 150W of heat for 30 minutes.

The rest is simply looking at your available battery sources. The newer brands of lithium iron phosphate batteries (e.g, "LiFe," A123) will give you that in a fairly compact size. I have not followed all of the developments in chemical methods. Pocket warmers for hunters would probably be in that range of heat too.

John

 

[bountyhunter]

Watts are Watts. Period. Li-Fe-PO4 batteries give the best power to weight/size ratio and they do make small 12V Li-Fe batteries for motorcycles with a lot of energy.

https://www.shoraipower.com/

 

[Geospar]

Heat from 12V battery.

OK...I'll look into both the battery and a chemical solution. Thanks John.

Geospar

 

[strantor]

Watts are Watts. Period. Li-Fe-PO4 batteries give the best power to weight/size ratio and they do make small 12V Li-Fe batteries for motorcycles with a lot of energy.

https://www.shoraipower.com/

Straight LiPo is a lot more power dense than LiFePO4. The only reason LiFePO4 is ever used instead of LiPo is because LiPo can be unstable like a cannibal on bath salts.

 

[tcmtech]

There is a bit of a cheat for this though. Use the hot side of a Peltier cooling device as your heat source.

You will still get your 150 watts of heat energy from a low voltage input source but the solid state heat pump will make it possible lower the electrical input wattage down by taking some thermal energy from the surrounding air instead of the battery system.

 

[bountyhunter]

Straight LiPo is a lot more power dense than LiFePO4.

I never recommend Li-Po because they have an unfortunate predisposition to catching fire.

 

[strantor]

I never recommend Li-Po because they have an unfortunate predisposition to catching fire.

yea, that's what I said

LiPo can be unstable like a cannibal on bath salts.