The gloves are on, exciting.
In a recent video I took apart a NiMH cell
and some of you were saying "Well, what's inside an Eneloop?"
And only way to find out what's inside an Eneloop is to take an Eneloop to bits.
So, I've got three batteries here. I've got
Tronic 2500 mAh from Lidl
I've got an Eneloop and I've got this
generic little cell out of a solar light
which is supposed to be 600 mAh
but now 74 mAh comes up when I charge it.
So let's just start opening them. So, I'm gonna zoom in a wee bit.
So you can actually see what's going on here.
I now use the same technique as before, basically
slitting around the top
and using the snips to nibble my way in.
I have largely discharged these cells
for safety reasons so they don't go thermonuclear on me.
So, let's nibble into this one
In the other one
it was quite an interesting arrangement inside. It was a
sort of a mesh, a honeycomb
electrode with a
black paste on it.
So, I'm guessing that this one is probably gonna be quite similar.
So that's the cap coming off.
I'm wondering why this one loses capacity.
It looks very similar to the previous one in a sense that it's got
a large hole in the middle of it.
Let's peel this back a wee bit further and see if we can
liberate the contents without stabbing myself in the process
or slashing myself on the sharp metal.
So, this is gonna come out? It's not really gonna come out.
I think it's wound out quite tightly against the outside of the cell.
Let's see if we can
peel it longways.
I'm trying to keep it in the shot here
But there is a possibility I may wander out of shot
in the excitement of tearing this to bits
Focus is gonna be a bit weird
I've got a rough focus position down about here.
But I may nudge a wee bit too high when I'm getting excited again.
So, we've got the separator
I'm guessing that when we come to the Eneloop
it's gonna be... The separator is gonna be the main thing.
But no, I'm not sure if it's gonna be visually different.
This one is already showing the slight difference.
I'll get the baseball cap off so it doesn't rub on the microphone.
It's showing...
I'm seeing a perforated mesh again here,
seems to be a common factor in them.
I have tried using this cutter which is for cutting pipes.
But it's not been that successful mainly because
they do seem to be coiled quite tightly against the side.
So I keep nibbing in this way and I use that as a last resort.
It is quite tricky, isn't it?
Another possibility is me to actually
spiral that in.
There's really not... Oh, there is a modest amount of the chemical.
The main differences between these will be the
chemical combination and the separators.
I'm not sure about the exact science behind the Eneloop,
the low self-discharge ones
I don't know if it's down to the separator just being...
This is why really,
it wasn't coming out easily. It's kind of physically eaten into the outer shell.
But the science of the Eneloop is not just the choice of the chemicals used.
The metal hydrides. But also probably the separator being less leaky.
Cause this looks almost like a fibrous material that's just been used.
As it was in the previous cell.
Yeah, this is not easy.
I get a horrible feeling that other batteries are gonna be the same.
But probably worse because they're gonna be so jam-packed with material.
I think I'm gonna have to just unwind it spirally like Pyrotenax cable.
Right, so here is what's inside. Let's bring the paper towel.
So this is what's inside that one.
It's very dry. I'm guessing that's probably why it's lost its capacity.
These lights tend to get very hot, the batteries
The whole light , the solar lights tend to get quite hot.
So I'm wondering if a part of the issue with them losing capacity
is the electrolyte gradually leaking out.
Is there a way you can make a hole in them and just squirt some more electrolyte in?
So, this one is just as that previous one was.
It's a mesh with holes in it.
And then this compound squished on.
Here's the positive, it's not very big, is it?
Okay, so that's the reference, here's the negative, there's the positive.
And there's a separator that's making a huge mess. i shall bundle that.
And bring in a new bit of paper towel. And then we'll take a look at Eneloop.
New bit of paper towel.
Let's get the Eneloop open. I have discharged this one.
Hope I've discharged it. If i haven't discharged that is gonna be quite violent.
Because these things can sink quite a lot of current.
Similar-ish construction, it's gonna be a wee bit harder to nibble this one open.
It's got a tar like seal, there's a black seal there.
I say tar, it's obviously not gonna be tar .
I'll move this out of the way, it's gonna provide a better contrast, isn't it?
And this one should hopefully be jam-packed full of chemical.
Because this is one of the cells that they're trying to get the absolutely maximum capacity into the area
that they've got.
So, how is this working?
That's kind of interesting for start.
Right, let's start peeling this down.
Again similar spiral construction, which, I mean, I suppose ultimately that makes sense. Let's cut that off.
This blue seal is just odd, it just sits on top.
It's rammed. You know, it really is just spiraled tightly in there.
So I'm guessing this is gonna be somewhat longer than the other one.
We've got to the beat here we've got about
so we've got electrode-wise we've got this to beat.
Which is about 2 inches(50 mm), maybe just a wee bit more.
Maybe closer to 60 mm.
Since this is so tight I'll just try and wind it down full length.
Also the electrode looks much, much smoother, also looks thinner.
That makes sense.
If they're trying to squeeze the material in.
The metal holding mesh, if you will. I don't know if it's gonna be a mesh, we'll find out when that's opened.
Opening my Eneloop, so you don't have to.
This actually so tight it's quite hard to get the snips in here.
Interesting though.
Very, very finicky to dig into.
Is it gonna just pop out?
That just feels really solid, it feels hardcore.
Which again, I would expect.
This makes me think that the really ultra-high capacities cells,
where they try and squash as much as is possible etc 3000mAh ones.
They must really compress that to get it in. I wonder how they actually do that.
I wonder how they slip in to the tube.
Perhaps they, with these cells they're aligned so it's springing back open once it's in.
This getting closer to the point that I can unroll this.
Yes it is, with a little finale, a little blue disk.
Okay, let's bring the towel in and unroll this. Is it going to unroll?
Yes, it is a mesh but it's a very thin mesh
It starts off, the outside starts off much smaller holes than it gets on the inside here.
So though it appears to be a one piece of mesh
It's got the smaller holes where it's actually pressing against the outside the case.
And then it's got the larger holes.
Not really sure why that is.
And this is just odd, it feels strange.
It's not that big it doesn't feel there's any mesh at all.It just feels like some sort of a compacted material.
And yet, I think there is a mesh in there.
But it's so thin and the material is so thick on the mesh
that it's very hard to actually peel it away.
When you do try peeling it away the mesh actually starts to crumble.
Is there a mesh or is it just reinforced in some way?
That's just so soft. I can see there's a metal structure inside but it almost look like it 's just
actual wire mesh, you know just like the woven mesh.
Very hard to actually pick it off.
It's so thoroughly ingrained into it.
I don't think it's a punched mesh like this.
Okay, so that's what's inside that cell.
Let's go on to the next cell. Which is the higher capacity.
Energy 2500
This one is coloured red, because when I get myself to keep them in sets I colour code them.
I just get a sharpie and just run it around the end to match the cells up for different packs.
So, let's get this one open.
So the signs of the capacity so far seems to be they just jaunt more stuff in, to be non-scientific about it.
And the mesh, I'm just guessing that's just to do with the current.
You know, being able to pass a lot of current down to the negative side onto the case.
Or maybe just a good coupling to the case.
Oh, that's something I didn't look at.
The separator. Is there anything really obvious about the separator?
No, there isn't.
Hold on, let's get the right battery, shall we?
That's the separator for the
It's two different types of the material by the look of it.
That's odd.
It's the same fibrous tight material this one seems quite dry
and this one actually seems the one that's moist, if you will.
Or is it just the fact that's it's got that coating stuck onto it.
They do look different, this one is a much darker colour.
That's just probably part of the science of Eneloop.
Okay, let's get this one open.
I think I'm doing fairly well, I'm staying in shot most of the time.
Okay, there's a little plastic topper as another one
Which I'm guessing if I peel that out, it will reveal it is jam-packed again.
We should think it would be, given that this is the highest capacity cell of these.
Well, that's not coming out too easy.
No, I think we'll have to get in a bit further before I can take that out.
There it comes. That is just jammed tight in there
I wonder the significance of two gauges of the cell, the mesh is another one
This one again looks a fairly fine mesh on the outside.
Is it gonna be the same on the inside?
Going the spiral approach with this one if I can.
I keep nudging back to the center of the camera.
Yeah, this one just feels rock solid, it really feels so tight
I wonder if the one they squirt the electrolyte down that end and that kind of makes it expand out a bit
or if it is just tightly rolled with a machine and physically just forced in.
Although you'd think if it caught the edge of it, that it would damage the outer coating.
So, let's get this right down to the bottom and see if I can get this off.
Guessing there's gonna be a little plastic separation at the bottom again
Yes, there's a little red plastic separation at the bottom of that.
Right, next bit of paper towel.
Not that it really matters, cause I've made a huge mess anyway.
And let's unroll it.
So it's starting off with a fine mesh.
Is it changing the size, this is the pinging chemicals everywhere.
The mesh is just pretty much staying the same size all the way along. And this one.
It's not a huge mesh.
Yeah, same size.
They've got an area where holes are not punched.
which I'm guessing is probably the same either side.
Okay, that's... There is actually, there's flames.
Okay.
Right.
Yeah, not sure the science of this, but this is all going in fire quite rapidly
So, that's quite an exciting chemical.
This isn't necessarily quite good. Where is my
explosion containment pie dish because my bench is rapidly going on fire.
Right, okay, one moment please.
So, that means this chemical here is probably combust
That's a bit interesting, I wonder how much I've pinged into different parts of my workbench here.
Is it just that version that's gonna do that.
Zooming back out.
Yes, right, so it turns out that if you open the
I mean that was fully discharged, I wonder if it is just reacting with air
That's definitely not something you want to stick in your bin, is it?
That was the little battery, the 2500 mAh one
That must be reacting with the oxygen in the air, that's odd.
That was the anode material, I think
It just bursts into flames apparently when you open the cell
That's not what I was expecting as you may noticed from my sudden loss of
knowing what to say there.
Yes, unexpected results. So, yes, I'll open my cells, don't you open yours
It turns out that they burst into flames when you open them, even when they're discharged.
Quite exciting.
My workbench is even more burnt now.
Anyway, a little bit of research says.
Turns out it wasn't a positive electrode.
Do not open battery. The negative electrode material may be pyrophoric.
It sure is!
Should an individual cell from a battery become disassembled,
spontaneous combustion of the negative electrode is possible.
This is much more likely to happen if the electrode is removed from its metal container.
There can be a delay between exposure to air and spontaneous combustion.
And I don't know if you noticed this, but while I was taking that stuff to bits
I don't know, if it was just reflections or actual little bits of the material
were actually spontaneously just fizzling and combusting
and it was the larger bit that was the more dangerous bit
I've still got bits here of random batteries.
And now, rather annoyingly, at 2 o'clock in the morning I'm gonna have to tidy my whole bench.
Really like everything of it,
because I want to make sure I find every bit of that material
just in case it bursts into flames in the middle of the night. That wouldn't be good.
So, yes, the moral of the story is:
don't open NiMH cells.
Some of them, not all of them but some of them can burst into flames.