Good morning all i've bought some of these. They are cell end caps, and i've got some more here now: they're, not um, 18, 650 cell end caps, they're, actually 32 650 or 32, 700 or whatever length you happen to have, and i've been waiting for these um, particularly because i want to know the dimension Between battery centers or cell centers, so what i can do is measure it actually from that edge to that edge, and it is not 32 because, of course, there's a slight gap between the cells. It's more like 34 and a half okay, 34 and a half millimeters, and that's important to know, because when i stack my cells, oh you haven't seen the cells. Have you well they're in this box here they are 20 of these um.

What are they? 32? 700. I don't actually think they're 70 across there um life pro 4, 6, 000 milliamp hour or 6 amp hour 19.2 watt hour cells and i bought 20 of them for 120 pounds. So these were six pounds each um, then the seller reduced the price after i'd received them to a hundred pounds. So what did i do? No, i didn't complain and try and get a discount.

I bought another box, so i now have 40 of these uh life. Pro 4, 32, 700, 6 amp hour cells and that's good, because 40 is divisible by 8.. So, yes, this is going to be my new battery pack now with um 40 cells. I could make up an 8s 5p five of these in parallel, but i think what i'm gon na do is make up an 8s4p that'll use 32 of the cells, and then i can make a 4s 4p for a 12 volt pack.

So i'm going to have 124 volt pack, that's the main pack that i'm going to use on my solar, crypto accumulation, machine and i'll also make a 12 volt pack so that i can experiment with how that might work on set machine and also to do general Experiments in terms of voltage, current charging, discharging balancing and all that good stuff. So let's make up a little pack. How do these things go together like that, and then you might put? Oh no. They go in that way.

Uh. You might have positive that end and then you might switch it around to have negative that and that's sort of silvered and then positive and then negative, and then we've got to um put these two together like so and push them over here. I suppose these should be the same orientation from the point of view of the um. The split there push that over there and we've got a nice little four cell battery pack.

Now i am thinking of doing printed circuit boards to go on the end of these. I think the first one i'll do will be just to go over four cells, so it'll be a square board and what i particularly want on that is multiple um balance, stud positions for putting little bolts on so that my wires are all not stacked on one Bolt, but also i want to put an acs-712 hall effect current sensor on the board. Now it did occur to me um. Let's say these are all one polarity here.

These are all positives. No, let's say these two positives and these two are negative. So if we've got current flowing in that direction, current flowing through the pcb could create a magnetic field which could upset the acs-712. So i'm thinking the acs-712 would be rotated so that current flowing through it is in a perpendicular direction to current flowing between the cells and therefore we shouldn't get magnetic uh distortion or interactional errors in the current reading.

That's my thought now, of course, the acs-712 is not measuring the current going between cells, because there's no point doing that because in a whole battery pack the current anywhere in the battery pack is the same. So you can measure that externally, just with a dmm a multimeter. No, this is going to measure current coming in and out of these balance connections, because i'm particularly interested in the balancing currents. How big are they with the flying capacitors balancer? How big are they with those inductive balancers, and indeed, how big are they here with the balancing circuitry inside the bms yeah, not very now, just so that i can play with these batteries? Um i've made up some little connector assemblies.

So, let's put that on there put that on there i'll need some nuts. These are four millimeter studs. So when i make pcbs for this i'll need to uh make the right size hole, i might make them actually five mil holes because of this dimensional. There may be tiny errors in that dimension.

Also, of course, these studs may not be brazed completely central to the cells, so i might allow for a little play. So let's attach these and make up a little 12-volt pack. So that's going to mean i want one running across there. Let's attach nuts onto that, and then these are my final terminals.

Oh, i need a bulb. Don't i well, i've got my trusty 24 volt bulb. So it's not going to be very bright, but uh yeah. There it is so that's a 12 volt pack, nice and simple, but it took a while to make these leads.

I don't want to make dozens of them. No. I want to do this printed circuit board idea, i'm glad actually that these have got threaded studs on both sides. I don't know whether you remember this thing that i bought on ebay oh little while back now and then the cellar just mysteriously vanished um.

This one has a sort of nut thread on one side and a stud thread on the other, but that strikes me as rather odd, because you wouldn't just simply screw these into each other and make up a really long line of these things. Would you it would be horribly subject to flexing forces and that sort of thing? No, that's just a peculiar arrangement having the opposite ones, on each side, no much happier with these and now, of course, i've got enough of these to make up a fairly large battery pack. I think um, the headway cells, the ones that are currently on my solar crypto accumulation machine, are 10 amp hour and they're much bigger than these much bigger. I think they're bigger diameter as well.

Now, if these are genuinely six and power they may not be, they may be five amp hour. Who knows we'll find out, then the headway sales i think comes to about 250 watt hours. If i built the entire eight by five pack of these, i think i worked out it's more like about 700 watt hours, so not quite a kilowatt hour yet, but certainly um. I can build a much bigger battery pack than those headway cells yeah.

Sometimes this is 34, actually that one is 35. sometimes - and i presume this is because the studs aren't welded precisely centrally - that one's about 34 and a half that one's about 34 and a half again and that one's about yeah that's 34.. So obviously, i think i'm going to go for 34 and a half but make them five mil holes in the pcbs. I think that's what i'm gon na have to do so heading out to the shed to check these batteries in context.

And what do we have? A solar panel with some sun on it - yes, as indicated by my sun indicator there, so yes, sun, um, oh what's the current i'm on the end of a wire here, so it's 1.28 amps and i think this - this smaller bulb works as a sort of 1.2 Amp current limiter, it's quite effective, so these will be charging more slowly than would be the case without that bulb. Now i need that bulb for the moment, because there's a solar charging issue which i'll have to come back to another time, but anyway, i wanted to see how these cells look against those cells in context, so i'll put it by the side of them. Yes, i think the headway cells, those the bigger cells - are a larger diameter and that would be indicated by well the size of the end caps. It's hard to see there, but i mean certainly the headway cells are almost twice the length um.

So are these going to be genuinely 6 amp hours yeah? I don't really know all right. Let's do a high current test. I've got my uh, oh what's this? Is it an h7? I think it is h7. 55 watt.

12 volt. Yes, now i've made this mistake before and put a 12 volt bulb on 24 volts uh, but this is 12 volts. Oh, yes, that lights up nice and bright um yeah, really just to see if these have got the grunt, i'm sure they have and of course when these are paralleled up. So if i do make an 8s 4p per battery, then yeah that's going to be well.

1C would mean 6 amps times 4 24 amps, nice and the other thing i'm going to do with these is i'll. Just stack them out that way, so that these connections are always accessible. This was done in this arrangement simply because the original bike battery had two lead acids which was similar in size to these, and so the logical thing to do with these was put them end on end. But the trouble is all the connections are down inside this gap.

You can see there's a piece of foam in there, because the bolts are really quite close to each other down in that gap. Yes, nice, bright sunshine. At the moment, this is actually allowing or 1.47 amps through. So that's, probably the most it's gon na yeah.

The solar panel is up at 35 volts, so well off its maximum power point. So, of course, if i change this bulb for the big bulb with this amount of sunshine, we should get a lot more amps, and that is three amps, so perhaps i'll leave that one on for a bit. Oh yeah, these are shot up into the three point. Fours range yeah, so since we've got a bit of sun today and my little oh, you can't see that, but my little um voltage controlled relay.

I can't move any of this stuff because it's all pretty rigid on the bench - 27.4 volts - that's set to trigger at 28., so yeah. Let's soak up a bit of this and get these cell voltages up to um, 3.5 or more. I think 28 volts on my relay trigger board is when these are all at 3.6. I think i worked it out to be that.

No, oh, the sun's gone in um. No, it's um 28 volts is 3.5 across the board. 28.8 on that relay would be 3.6 across the board. That was it.

The sun's come back out. So these are my new uh cells, which i'm going to use to make up a battery. Now i'm going to put links in the description below to the seller, who's selling the cells. If he's got any more, i think he had 10 sets up for sale.

That's 10 lots of 20. and also these 32 millimeter diameter end caps, whatever they're called array caps that sort of thing yeah, those will all go down in the description below and not sure if this is going to work. Actually, that works quite well in reflection mode, but this is a very dark welding glass, let's put it over the camera. Yes, so you can see that it's not a clear blue sky today, quite a lot of cloud.

Oh, i can't see anything, i'm being dazzled, so this one was just a short video really to introduce my new, that's just not going to connect. Is it reliably uh my new life pro 4 uh cells, which i'm going to use to build 24 volt and 12 volt batteries for my solar crypto accumulation, machine cheerio.