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Heating element/dc low voltage

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Tony12345

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Hello, I'm trying to make a small heating element to warm up about 4oz of fluid to 100-110 degrees Fahrenheit in a decent amount of time(2 min max). I would like to keep the battery/batteries small (9v's aa's or a custom lipo ) Any ideas to make this work?
 
Work out the amount of energy you will need to do the task, you also obviously need to know the starting temperature of the liquid.

Then you can work out what kind of batteries you need.
 
The liquid will be around room temp. I'm new to all this. What do you mean by work out the amount of energy you will need?
 
it will largely depend on how much heat your losing at the same time.
  1. what container will you be using
  2. will it be insulated
  3. what is the ambient temperature
  4. presuming your liquid is starting at ambient
  5. how long does it need to stay at that temperature
 
The container will be glass, non insulated. The ambient temp will be 65 degrees Fahrenheit. I would like to keep the heat for a half hour to an hour.
 
You will obviously need a thermostat, is the hysteresis going to be a problem?
Can you insulate the flask?
Can you use this 12v 65w immersion htr on ebay 371411432040
Or cup heater 281689712609
Using a Lipo battery.
Max.
 
The first element is way to big. The cup heater idea is close to what I want, but I would like to make it smaller. Smaller the better.
 
The first element is way to big. The cup heater idea is close to what I want, but I would like to make it smaller. Smaller the better.

Like I said above, do the calculations for the power required - if you don't know how, then google is your friend - but briefly it takes one calorie to raise one Gram of water one degree Celsius at one atmospheric pressure.

You would also need to substantially insulate the vessel, in order for it to heat as quickly and efficiently as possible, and also to stand any chance of remaining warm.
 
Try a heating element out of a cigarette lighter (usually free) and feed it with ~3.6 V from a Lithium cell. Am guessing it will rise 40F to 4 ounces in a minute or two. Play with voltage and heat shielding to tailor results.
805137584_tp.jpg

Or unwind the element coil and wind it around the glass container to be warmed. End connections must be crimped.

Or drop a proper incandescent bulb wired to a battery into the contained fluid, silicone on crimped contacts.

Want to go fancier ? Shine infrared LEDs to the liquid, as many as needed to achieve the result
iu
 
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Is the liquid aggressive (i.e. is it likely to attack/dissolve a heating element)?
Does the heater need to be food-safe?
 
...but briefly it takes one calorie to raise one Gram of water one degree Celsius at one atmospheric pressure.
Which doesn´t help much when we got weight of an unknown fluid in ounces and temperature rise in fahrenheit. And then there is the calorie.. ;)
 
The first element is way to big. The cup heater idea is close to what I want, but I would like to make it smaller. Smaller the better.
Is the actual thermal 12v coffee cups too large? they are insulated and thermostatically controlled. You maybe could tweek the temperature/thermostat to close to what you need.
Max.
 
0.25 pounds of water raised 40F takes 0.25 x 40 = 10 btu = 3 Watts

About a Li-ion cell into a 3.3 ohm resistor, drawing 1 Ampere.
New-and-Original-Cement-font-b-Resistor-b-font-font-b-3-3-b-font-font.jpg
 
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0.25 pounds of water raised 40F takes 0.25 x 40 = 10 btu = 3 Watts
And there I thought that BTU is a unit of energy, not power.
My numbers say you need to blast roughly 100W for 120s to rise 113g of water by 25°C.
 
24V cheap Chinese soldering iron heating element, get the ones with 4 wires (2 are for the heat sensor), you can slip inside a borosilic glass tube if needed or just tie around the outside of something.
Give it 24V and it gets hot VERY quick, give it 12V and it gets hot quick, give it 9V and it still gets hot but managing the tempreture at 9V is easier, great for small amounts of space or liquid, I use them alot for boiling tube heaters but I slip mine inside glass made to take heat then put that inside the boiling tube
 
Hello, I'm trying to make a small heating element to warm up about 4oz of fluid to 100-110 degrees Fahrenheit in a decent amount of time(2 min max). I would like to keep the battery/batteries small (9v's aa's or a custom lipo ) Any ideas to make this work?
Here is a calculator. When I ran it it came out 80 watts for 2 minutes. Longer takes less of course.
**broken link removed**
 
Here is a calculator. When I ran it it came out 80 watts for 2 minutes. Longer takes less of course.
**broken link removed**
That calculator rounds it off severly, try typing in 113 liters instead of 0.113, you will get that 2 minutes at 100W, and 2.5 minutes at 80W with 100% efficiency.
 
That calculator rounds it off severly, try typing in 113 liters instead of 0.113, you will get that 2 minutes at 100W, and 2.5 minutes at 80W with 100% efficiency.
If I use .13 liters, 18.3C to 40.5C and 80 watts I get 2 minutes. 130 liters 2282 minutes. So the error must be about 10% at the low volume.
Is this the error you are talking about?

Anyway he's not going to get there with a couple of AA batteries.:D
 
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