So, I am looking to make a small water boiler, using a coil, and either 1 or 2 AA batteries. This is mainly for proof of concept. I only need the coil to reach 100°C/212°F. I also need it to reach that temp almost immediately, similar to how a nicotine vape works. What metal can I use? Would copper be good, or should I stick with standard vape heating coils?

 

AA batteries == Very small amount of current available, due to high internal resistance.

This is why you never see vapes that use them.

Boiling water == LOTS of energy, harder than you think to boil water with batteries.

 

Ok, so scrapping the AA battery and going with standard vape style battery, with higher current, which coil metal would be best? I do not want the temp going over ~115°C

 

A metal that has high bulk resistance
A metal that does not oxidize much at high temperatures.

The temp the wire reaches is difficult to predict, It depends on the supply voltage, wire resistance and the rate of heat loss.

 

So, I am looking to make a small water boiler, using a coil, and either 1 or 2 AA batteries. This is mainly for proof of concept. I only need the coil to reach 100°C/212°F. I also need it to reach that temp almost immediately, similar to how a nicotine vape works. What metal can I use? Would copper be good, or should I stick with standard vape heating coils?

Welcome to AAC.

As @Sensacell pointed out, using AA cells is pretty much a non-starter if you want to boil more than a tiny amount of water. But without knowing just what you are actually trying to do it’s almost impossible to give any meaningful advice.

You gave us a just a little information about a possible solution to some mysterious problem. Please tell us what problem this solution is expected to solve. What is the application this is part of?

If it is “secret” then you should consider how much it is worth to you and hire a qualified engineer, have them sign and NDA, and let them review the entire project so they can provide competent advice. The value of any advice you will receive here is going to be constrained by your own ignorance in presenting the problem—that is, your naive ”solution” to whatever the problem is.

The only general advice I would give you is that your “similar to a vape” suggests that you research how they work since they’ve already (it seems) solved this part of your problem.

Good luck.

 

Hello,

For 115 C steam an over pressure of about 0.7 bar is needed.

Bertus

 

A suitable material for the direct immersion in water would be a "NICHROME" alloy, commonly used for electrical heating. That name covers a variety of alloy variations so you will need to visit supplier information for information on selecting what you need for the undisclosed application.

 

For what it may be worth, in looking for a good 1 watt LED driver from a 1.5 (or so) volt cell, I found that the internal resistance (per Sensacell in post #4) was often the limiting factor. I ended up using Ni-Cd since I could not trust any of the Li-Ion cells I could find in town, and none of the carbon-zinc cells and similar could push out enough current.

 

I appreciate all the replies. Basically, I was looking to make an alcohol version of a nicotine vape, hence not wanting the coil temperature to go to high, avoid accidently igniting alcohol vapors. However, after doing a bit more research, I found that alcohol vapor has a significant negative effect on the lungs, and I've scrapped the idea entirely. I let my enthusiasm for the idea of a vape "bar" get the better of me, and was looking at the technical aspect before I finished researching.

 

Good for you!

 

Well the idea was to use the vape to create low concentration version of what happened to you. Basically, tipsy without the bottle, or the call to nature.

 

I think that the OSHA folks would get very excited about what we did in a routine manner back then.
I realize that this will terribly offend a lot of people, BUT I believe that individuals ARE responsible for the results of their actions. I realize that goes counter to many mindsets, but "Oh Well".
Of course, for many years cigarretts were harmless, except for starting fires, and then all at once they were not so harmless.
An alcohol buzz machine is an interesting concept, though. And what we got in that shop I have no idea as to what the concentration was, high or low.

 

When I shortly worked in State Prizon (for invited physics tutor at secondary school for inmates) I observed those guys was boiling water in their cells, where electric mugs for unknown reason was disallowed (probably that 2 liters of boiling water is potentially deadly weapon?), by immersing two beard razors in the cup to the 220 V mains. Later we discussed the chemical result of such method when teaching both Farady electrolise laws.