Hello, some more sodium ion batteries. Um I've got 18650s here. 1300 milliamps. Uh, these are 26 700s.

I'll find the capacity in a moment and these are 33140 so they're 140 mm long. So let's start with the 18650s. uh, standard size these are. There isn't much in the way of um identifying numbers on here.

In fact, when I look at the reference code, it's actually the same as the code on the 26 700s. Now these are rated at, 1300 milliamp hours. Uh, the ones I got previously 18650s, they were rated at500 milliamp hours but they said charge to 4.1 and discharg to 1.5 which seemed a bit excessive. These are rated I think a bit more uh, sensibly at300 100 milliamp hours and the ratings are charged to 4 volts and discharged to 2 volts which was kind of the range that I concluded was a a sensible range when I put one of these on uh, the discharge tester.

Now, these cells have been very kindly supplied to me by Shenzen Asia Technology Company Limited and this is their Alibaba Uh page. but you can get to this simply by going to EV Pro Max.com So I'll put um, that link in the description below this video and you can see here. Um, the sodium ion products that they have here are the 18650s. Uh, if I scroll down a bit, here are the 26700.

Okay, they're saying uh, 3.3 amp hours for those. And here are the 33140 cells which are 10 and Powers now on the 33 140s. Uh, there is a bit more detail. it says here: 30 W hours uh, 3 volts nominal.

so if we divide 30 by 3 of course we get 10. ow so these are 10 amp hour cells. it does say on here 32140 but these do actually measure 33 so we'll just check that with this thing. So uh, there it is 33.1 diameter and because I knew they were going to be 33 I actually bought these um 33 mm end caps and they do uh, fit perfectly well in those.

So I do have what I need to make up a pack? um, containing these large 10 amp uh, sodium ion cells now I've ordered holders for the 26700 so those will be 26 mm diameter. Those haven't come in yet so I'm waiting for those so those can hang on. So probably what I'll do is I'll probably make up this uh pack first now since these are 3 volts nominal each I think the sensible thing to do would be to use four of these uh to make up a 12v nominal pack. so I'll put these positive this end and then negative this end two more on top.

uh so that will be positive that will be that way around and then fit uh, the other end cap here and then in order to if I can get that on in order to uh, hold that together I've come up with the idea of using a cable tie. So I think what I'll do is I'll I'll drill out a hole in there and a hole in the opposite end, pass a cable tie through and then cut off the little uh clip, end on on a shorter cable time and just put it on there so it just holds this thing together. Then I will spot weld on the Uh nickel plated steel strip across uh there and then a couple down there and then a couple of strips on my two end points Mount this on a piece of wood and then perhaps use some Uh Banana Star terminal posts as my Uh connections. Banana plugs are good for at least 10 amps.

so uh I can discharge and charge these at 1 C Given that these are 10 amp hours um, and uh, looking again at Evpro Max.com which is this Alibaba page. Um, you can see that um. also for sale are these prismatics uh 200 amp hours. You can also get get sodium ion pouch cells.

You can get sodium ion madeup Uh batteries. There are also these 46 150s but I couldn't find endcaps for 46 mm diameter and there also these 40 mm diameter Uh cells. but again I couldn't immediately find endcaps for those. Now let's take a look at these 33 140 cells.

These are the ones I'm going to make up a a 12vt nominal pack. So here's the listing for those cells and there is quite a lot of data on these. Um, if we come down here, we've got um now this is quite small so you may not actually be a to read this but nominal capacity 10 amp hour nominal voltage rated voltage this says 3.1 volts Uh operating range is 2 Vols to 4 volts. Also got Um charging working temperature -10 to + 55 and discharge working temperature -30 de to+ 55.

Now this is interesting safety performance: Fully charged one C to six volts no fire, no explosion. This is over discharge 90 minutes at0 2C down to NV State No fire, no explosion and in fact all of these under all these um cases of short circuit, heavy impact, hot abuse Extrusion and fall. All of them are no fire, no explosion. So these cells are pretty safe, but it will be interesting to work out how to deal with this issue.

That although the nominal voltage is 3 volts, so this pack of four cells will have a nominal voltage of 12 volts. the minimum voltage of a cell is 2 volts. so this will start at 8 volts and the maximum voltage of these cells is 4 volts. So this will have the range 8 volts at the bottom to 16 volts at the top and that might create some issues.

CU I'm thinking about this for lighting in the Shar but it could create some issues with LED strips. So here's one of the lighting strips that I've got in the shed. These are about a foot and a half long. so I just take that out and take a look at this resistor.

We got three LEDs in series and and a resistor and then that's repeated in each little section and the resistor is 390. Ohms. So let's jot this down a minute. So we got um, 12 volts here and Z volts down here.

Uh, what should we say? these are these are white LEDs So let's call them 3 volts each. That leaves 3 volts across 390. Ohms. So we've got uh, 3 / 390 is so 7 and2 milliamps through the LED string.

Now, what happens if we reduce the 12 volts to 8 volts? Well, if we're calling these 3 volts each, then they probably won't be lit up at all. Now they might not be 3 volts each. And of course, that 3 volts changes depending on how much current you put through them. It might reduce if you put less current through them so there may be a faint glow, but they're certainly not going to be very bright.

And then what happens if we put 16 volts up here? subtract 9 Volts for the three LEDs That leaves 7 volts across 390. Ohms. And yes, that's double the current. That's um, 18 milliamps.

So you go from 7 and 1 half milliamps at Uh 12 Vols to 18 milliamps when you got 16 volts here, and possibly down to as little as0 milliamps if you've got 8 volts here, So we can do one of two things: either work within a smaller range of voltages, maybe run from Uh 14 volts down to 10 volts, but then, of course we're not using the full capacity of the cells, or we put some electronics between these uh, this pack of cells and the light strip. um, a buck boost converter, which whatever goes into it, it'll always puts 12 volts out. So there are solutions and I will look at uh, these Solutions initially I'll probably just hook it up to the batteries and just see see whether there's a problem putting 18 milliamps through those LEDs um and how much brighter they are at Uh 16 volts and how dim they are at 8 volts. So big! Thanks to Evpro Max.com for sending me these sodium ion cells these Um 1300, Mah 18650s, these 3300 milliamp, uh 26 700s and these 10,000 milliamp, uh 331 140s I'll put um a link to the Uh website Evpro Max.com which will take you to an Alib Barar page.

I'll put that in the description below this video. Um, for now, that's it. Uh, but I will be making up battery packs with all these sodium ion cells cuz I just find them quite fascinating. Uh, but that's it for now.

So cheerio.