I thought it would be a good idea to compare one of the mystery gas producing cells from an air freshener with a standard zinc-air hearing aid battery.
I bridged both with a 270 ohm resistor to give a controlled current flow, and sealed them inside syringes with some silicone grease on the plunger for an extra seal, then left them to do their thing.
A zinc-air battery is a type of cell that uses the oxygen in ambient air to facilitate an internal chemical reaction. They have some small holes in the cell case, and are supplied with a tab that covers them during storage to prevent the chemical process occuring. To use them you pull the tab off to expose them to air, and they then produce a voltage of about 1.3V.
They are commonly used in hearing aids because they have quite a high energy density and once activated tend to be used immediately.
In this weird application they are deliberately starved of the oxygen they need to generate current, and when a load is applied the smaller voltage they produce passes current through the load and they produce hydrogen gas at a rate determined by the current flow. This allows devices like grease dispensers and air-fresheners to use a simple resistor to set a gas generation speed with no external power required.
When I first discovered this approach in an automatic grease dispenser I mentioned it to AvE who was the inspiration to take the grease dispenser apart in the first place. He has done his own experiment linked here:-
https://www.youtube.com/watch?v=Ppm9b0JAQCQ
Here's a link to the video where I discovered these cells being used in an automatic lubricator:-
https://www.youtube.com/watch?v=Be9RU3PU1bw
I specifically avoid using intrusive mid-run video adverts, which means I don't earn as much from my content as other YouTubers.
If you enjoy these videos you can help support the channel with a dollar or two for coffee, cookies and random gadgets for disassembly at:-
https://www.patreon.com/bigclive
Patreon supporters get early access to advert-free videos as they are made, and also regular live streams.
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
Other contribution options are available at:-
http://www.bigclive.com/coffee.htm
#ElectronicsCreators

Time i want to find out if it does actually work when you get a a zinc air cell and you stick a resistor across it and put it into very small enclosure with very little access to oxygen. And see if it does generate hydrogen push this out and the only way i can think of sealing these up properly. Because the hydrogen is very uh. It's a very small molecule and it will find its way out of just about anything so the way.

I've thought about doing. It is to actually melt the ends of these syringes after i've pushed the plunger in as far as it can go. And you can see this seals. Really well you can actually see it clouding in the end of that when i tighten that up pretty impressive and it things back out.

I'll also maybe we wipe of silicone grease around these just to try and make a better seal. So here's what i'm going to do here is one of the cells instead of completely peeling its little label off. I'm going to put a resistor in and then put the label back down just to hold that resistor in position. It's a 270 ohm resistor.

So that's now clamped back down in that and i'm going to fold. It up like this maybe pull it out a little bit more so it can fold up keep it as small as possible and then i'm going to fold. The top across and use a bit of heat shrink to hold these in place so i shall crop these wires down with a pair of side cutters and make sure i don't short it out completely. I think it'd probably still work.

But you know i want a scientific experiment. Here i want to control the current. Then i shall put a bit of heat shrink sleeving across it like this and grip. It with a pair of ceramic tweezers to protect my fingers and then shrink.

It all down so it holds the connections in place. I really should zoom down this shouldn't i this would be better so we can get a better shot of what's actually happening here. So i'm going to grip this i'm going to get the hot air gun and i'm going to shrink this down so it grips everything into position hopefully sometimes you find with the heat shrink once it uh once it cools down it sort of relaxes a little bit again so hopefully that will be holding those we can measure across the resistor and find out and see if we have voltage across the resistor. So there's the first one let's bring the meter in and see if we got.

Voltage which won't be very. High it will be something like. 04. Volts or less touch it to there and to there.

Yeah. 06. Actually at the moment. Because it's how do we burst of air right too or into its syringe.

It goes. It'd be nice. If it went longer like that oh. It is it's going to fit right through a bit of grease a bit of gray silicon grease.

I shall just rim it and uh plunge it in get that sit down sit down. No. It's decided not to sit down. There.

Oh one nuisance lie down flat. There it goes now. I'm going to put this in give it a wee squish around push it right down to the point. It's virtually touching that cell.
Which is just refusing to stay flat. This is what happens when you're experimenting nothing ever goes to plan stay flat so goodness sake blooming. Heck yeah. That is not going to plan.

I want to squeeze as much of the air out as possible let's see if i can drop it in like that it's down push this down and then we'll bring the heat gun in again and we'll heat the end of this up until it starts to melt and then i shall pinch it together with my bare fingers at the risk of burning in the process. This is a i've tried it before on that other syringe and it goes kind of glass. Like initially it was very clear and once it's gone clear. I shall just pinch it it is a bit like glass.

But it is plastic that is it pinched right here so that should be sealed. Now and theoretically if that does generate a hydrogen. It will push this plunger out right okay. Here's the next test is this other cell.

Which uh maybe. I should cut a small bit of tape maybe i should get the silicon grease off my fingers. He said wiping them in his pants. Which isn't necessarily the best thing to do uh right tell you what i shall peel this tape with this one and do the same again i put a bit of captain tape over this just to try and keep it protected from oxygen for this experiment.

So this is an actual cell. That came out of a air freshener that uses the gas generation to squirt its stinky schmoo out so let's fold this up put it across like that oh it's trying to get out it's trying to escape it's okay i'll shove it back in and i shall crop that there get another bit of heat shrink across i'll just leave the captain tape full height here maybe i'll just grip the resistor with the uh. This is a good idea. It's probably a terrible idea that could also do being just pushed in a little bit more at the bottom.

I'm just uh rambling. Here just why i this is experimental. I'm just making it up as i go along this is how you experiment. This is how stuff gets designed so that should be shrunk down suitably uh.

If you're thinking that the shrinkage of the heat shrink is going to stop the gas escaping from the little holes at the back. It will find its way out it will push its way out particularly around that resistor lead. So let's uh test round this one so am i getting voltage yes. It's actually because i've exposed.

It air the voltage is shot up in this one not convinced that's going to make the best connection. There. But hey it's an experiment. This is where i could have done it cutting that it might not end up going down.

So easily long ways is it going to if i use the tweezers to tweeze it in i may have to trim some of that heat shrink off with a sharp knife sharp knives. I have blunted all my knives so you excessive violence oh that is so blunt. It's just basically trying to pull the heat shrink off that's no good i really need a new blade. I've been cutting uh tarry.
Felt and that's very abrasive it's uh got the grit all over it so it's wrecked that blade completely. He said poking the blade as if to prove the point so let's pop this down. Here try and get it to lay flat. As before mush.

Then i shall put some grease in this one and put it in and heat this one up as well and this is a real gas generating cell. So it should do something or maybe. Neither of them will do anything time will tell and really. It is time the next bit of this video is going to be some time hence maybe days.

Hence because i'm not sure how long it will take for it to start doing it i think. It has to use up available oxygen first before it can actually move on to uh generating. The hydrogen. If it even does generate it pinch that shut.

Oh that's very hot yes. Indeed. That's working fingerprints now implement imprinted. So there are our two syringes now all we need to do is wait so uh well basically.

Speaking one moment. Please. Progress report movement has been detected overnight and approximately four days later the surrender. The hearing aid battery in it and the 270 ohm resistor has produced approximately 10 milliliters of gas.

I'm not sure. It is supposedly hydrogen. I have a naked flame here to test that we shall test that the one with the battery out of the well the gas generating cell out of the air freshener uh has not achieved the same amount of gas. But having said that to do this test properly because hydrogen is a very small molecule it finds its way out through any crevice even though i put silicone grease in these there is a risk that maybe some has leaked out to do the test properly and put maybe two or three of each cell in separate syringes.

So that i got an average across those syringes meanwhile. The grease dispenser. I replaced the batteries in it with a couple of zinc air cells and because i completely block bloke broke the resistor i replaced it with a resistor across and it's interesting to note that because there was already an air pocket in there and i'd had it open it kind of didn't do anything for a while until it consumed all the oxygen the air and then it started producing uh pressure to push the grease out with with a plume so uh. Interesting that these things you really need to try and uh put them in a small spaces area as i did here so there's not too much air to interfere with the operation because it is the starvation of air that seems to make it do this thing.

Okay now comes the flame test. This is hydrogen. So theoretically. It's lighter than air it kind of popped and it blew the flame out a bit of an anti climax.

But then that's because it's pure hydrogen and not oxygen as well. But you can see the steam in here. It has burned so that was combustible uh. So let's just say that was hydrogen and this is silicon grease rad.

I'll just pop that right back in there actually you know what oh no i can't do that anymore. Because uh now i've broken the ceiling. But there we go um. It does appear that standard uh zinc air cells can be used to generate pressure in confined spaces in a very controlled manner just by putting a resistor across them particularly well definitely when you starve them of the oxygen.
They need because then they do that other thing that they produce hydrogen instead. I'll put a link to abe's video. Eve has been experimenting with this as well arduino versus evil. But so far this is a very interesting thing it's uh something that wasn't really expected to be so simple and the odd effect of a standard zinc air cell.

That has this other function of producing reasonably high pressure gas at significant enough volumes some of the manufacturers that make bovarta claim that one cell of their special gas producing cell will produce about 150 milliliters of gas a very interesting well worth exploring.

9 thoughts on “Standard zinc-air cell vs mystery gas generating cell. flame test”
  1. Avataaar/Circle Created with python_avatars Lumibear says:

    Yeah that silicone lubricant goes everywhere doesn’t it, stains fabric too, great stuff though, doesn’t dry out, latex & rubber safe…

  2. Avataaar/Circle Created with python_avatars Mike says:

    You have just made H2o from recombining oxygen and Hydrogen with a spark. . The steam proves that is was hydrogen. And the candle went out i think because you used the oxygen around it to make water inside the syringe. You just made a hydrogen fuel cell ; in a very simple way and, also demonstrated the practical problems associated with oxygen reduction. Big Clives Alchemy channel coming soon. 🤞🏻

  3. Avataaar/Circle Created with python_avatars Snakez De Wiggle says:

    So ceramic tweezers lay idle, while you burn your fingers ! Hardly science ! 👍👍👍
    😉

  4. Avataaar/Circle Created with python_avatars Reno Simpson says:

    Glad the 9181 is coming back

  5. Avataaar/Circle Created with python_avatars Ford Minton says:

    greasy clive is best clive

  6. Avataaar/Circle Created with python_avatars Moon Moon says:

    Something something that’s what she said to rimming and plunging it in.

    …and lying down flat.

  7. Avataaar/Circle Created with python_avatars Eric P says:

    Someone’s using batteries for their non-electrical properties again…

  8. Avataaar/Circle Created with python_avatars j s says:

    very cool

  9. Avataaar/Circle Created with python_avatars A Generic Account says:

    Load up a balloon next time. Big boom.

Leave a Reply to Ford Minton Cancel reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.