All right, today's video, we got some of the pcbs, the sample pcbs for the 2170s. So let's put them together and then let's run some tests and see how they go, maybe they will be able to do more than five amps. Maybe not the only way to test is to actually test it, build it and test it and put a load on it and do this thing right, so let's do it all right. So, let's start here we have the five boards.

We have five of the fuses and the fuse holders and then the idc connectors and then the actual battery holders right so we're gon na start by soldering, the connector first and according to this, is gon na. Go like that. So here we go so usually on the high power boards that i do. I make that hole expose, so that is one big clump of uh solder in there right, but these are four five uh amp fuses, so this yeah this is not those two little pins.

Can handle five amps, no problem, that's what i'm trying to run like 20 amps through those that that's a good thing, and i think it actually makes it easier to solder those too okay. So that's there! Now, let's do these ones here, some positive! Oh look! These are already, this is cool. These holders are already uh, marked as positive on one side and positive data, the other holders - sometimes it's positive here and a negative, and so they change you know, but these are so. You just have to follow positive on this side.

Negative on that side, just like that and then there's a little gap in there, so i guess i can close that up a tiny bit. I don't know - maybe not - maybe it's not worth doing that so now we get to see if these holes right here that size, if it's uh, if they're the right size to be able to help you quickly solder them, because that makes a difference depending on the Homes, how much time you take? Okay, yeah! That's not that bad! Remember! We have to uh s solder a lot of these, not this specific board, but the other size all right and there's our board. There's your first board yeah. This is, if you're only going to use one, and you want to put one of those connectors in there, then you can do that.

Uh yeah, there's many reasons that just like to put down there. So you, you could have the flexibility to do that sort of stuff right um, but most of these boards are gon na be stacked together. So we don't populate that uh. This is basically the the majority of the things that you have to populate now.

The other question is: do we want to have these fuses on the back side instead of the front side? Well, let me see when you put this in like this. That's another question. So if you have an opinion on that, because they're more accessible from the bottom right, but when you have a battery like that - and it's all placed like that - then you can see it. Although you can't, because it's gon na the connector is gon na, be there in the way this connector goes in here, so it goes to the next, so you can only see the top on the second one.

It's going to be in the way you know. What's your opinion, all right so now uh, the last thing is just to uh populate them with the battery cells right. So this is a brand new box of batteries. So i'm not even going to check the voltage.

I guess we can check that later, but basically loaded up positive and then negative right. So the positive is the one that has got that little thing and then the negative is just super flat and the boards are all negative here and then positive there. So one thing that would be useful is, if you put the a cable here, you can check battery voltage just in case you get some that are weird, so get some way. The way off right.

These ones are not. These ones are pretty. Even i we expect because they are new, but you never know you can't just trust something blindly right then. The other thing is, i already put 25 millimeter standouts, which is the same ones that we use for other systems for the 3400 uh for the 18650.

So then, so here's one thing they do touch if you bend it down like so i might add just layers or lines of paint in the back here, so that there's just an extra layer of isolation between the you know, because it's a so it's a copper And then there's paint right and then there's this, which is the wrapper the cell wrapper, but then i would like to add at least another one, just in case right just in case you put this in a place that vibrates and with time you know you don't Want that thing to, or you want to eliminate the chances of that thing uh, you know touching wearing out chafing the all those layers of isolation, so that you know then a little short out or whatever. So there we go. Okay, these next two have a different uh higher fuse. This is a seven and a half, and then this one's a ten we're going to use this to test.

If we can push those farther than five amps right. All right, so here is what's happening, uh in order to load test this and see how much we get from those pins there. We have to charge the batteries, and so i uh assembled it into this pack right here. Right and now i am charging that pack using a uh variable power supply right.

Here's where the cells are at. I have put this thing: the ribbon cable across all five of these boards, so now they're all connected. So now, uh, like one of these cells, can't just go crazy and go. You know out or go above without us knowing right.

So basically, what's going to happen, if one of these cells decides to go up uh, then this thing is going to start beeping and then it'll alert me that to come and check on this right, but basically 5 amps per bore. 5. 10. 15.

20. 25. So you can charge this and discharge it at a rate of 25 amps or more now. I don't want to load it just now.

I think i just wan na this is the first time that we charge these batteries. I don't know how long they've been there. They're brand new we're just gon na go easy half of that 10 amps right so about two: eight ten yeah so about two amps per per uh string of cells. Yeah, that's about uh what these battery packs or these cells want to get charged at.

So we're just going to charge it all the way to 25 25.9. I don't know 25.9, oh yeah, yeah all the way to 29 right uh. Now this is going to be the load, or i at least i'm going to attempt to use this as a load, because you can adjust it. So it's a grid tie inverter that is adjustable with this little knob here and small one, because we just want to basically load those with like five to ten amps, and if that doesn't work, then well, you know we'll bring one of the big ones over there Or whatever um so we're gon na let that charge then we come back we'll do that test.

We'll do the thermal thing and then we decide uh what changes we want to make to these boards and then you know we'll do the next revision in the next iterations all right. So here's our test setup, the batteries uh, are here uh. This has a 10 amp fuse right, because i want to see uh at least 10 amps loaded up with the 10 amps and see how hot it gets here. Are our cells it's actually discharging at a rate of 3.6 amps right.

This is a grid tie inverter that i can adjust not very finely, but i can adjust it um right now, it's at 3.6, so i'm letting that kind of heat. I should put it around five: oh there. It is okay, so 5.2, that's the maximum that i all my other testing uh. You know i came up with that uh because at five amps these contacts would get a bit hot right.

So i was like above five is too hot below five: it's okay! You know, and so right now, it's five. These contacts seem to be almost the same as the other ones uh. Even though it's a bigger sale, i thought they would be wider or different, but i they seem to be the exact same ones. So we shall see if that is the case, because it would, they will react the same way if they are right at five amps.

You know after a few minutes, then they will be um hot because they have a lot of resistance. The reason why that would be is because the material in here is, you know it has high resistance. It's not very good conductive right, um they're not made out of brass they're, not made out of copper or if they are, i think, they're plated with some other material. I don't know what material is, but it's not very, very conductive, at least on the 18650s on the 20.

700S. 21 700s. We don't know so that's why we're doing this test. Can we load this for more than five amps? We shall see.

Let's go look at the thermal camera all right, so here it is at five amps um after about a minute or so those contacts are well they're, glowing right, but they're glowing. Look the hottest part of this thing. You see it over here in the side of the screen is 31c, so that is, you know that is uh. Let me see it about the temperature of my hand, yeah.

I think my temperature, in my hand, is a bit higher than that right. So it's not super hot 31c. I don't know, do the calculator, i don't know what it is in fahrenheit, but it's not hot. It's just barely very.

I think it's it's above ambien, it's kind of cold. In here there we go. That's my heater! It's that cold! That i have that i'm running a heater here, so man - maybe i can run them five amps more more than 5 amps, let's see so okay. So it's been a minute since we've run this thermal camera and the temperature seems to be pretty stable.

There huh just a bit more of five amps, we'll give it another. Let's give it another three minutes, and then after that, we'll bump it up, because you know where we're trying to find out here is the continuous load right, the continuous uh performance of these, not peaks right. They can handle peaks um and the reason why we want to know because then we can fuse it accordingly right now, you know i put five amp fuses and all my other boards, because that's what those holders! I don't want those holders to see more than five amps continue, so if they do, then that little fuse blows and it prevents uh your holders from melting right due too much to too much heat. And so you know, when you have a large pack there and every board is fused at five amps.

If the total load exceeds more than five amps per board right, then just those things will start blowing and then it'll save your it'll. Save your your holders. It'll save your pcbs from just melting right, and you know who knows something more catastrophic, like maybe a fire or smoke or a thing. Your battery, basically just disconnects itself.

Boards will start disconnecting themselves, one by one, and i think it'll start like a chain reaction right. As one board disconnects, then the overall load goes higher on the rest of the boards that are connected and as soon as that happens, then all the other boards then start uh blowing right. Unless you get some uh fuse. That is uh.

That, maybe is defective. You know these fuses are not very high quality they're, you know, there's just a piece of material and it blows around the rated. You know uh rating on it right the stated rating on the thing, but some probably blow much sooner some blow much higher. You know it depends if you run, i think a fuse continues, so it gets hot and it gets cold and it gets hot and gets cold.

That also is going to change with time. I think uh. If so, if you have one circuit that runs close to peak all the time and then one that never reaches, then that one's likely, you know more more likely to to go off and stuff. So it's all kinds of there's all kinds of uh variables that come into play here, but you know fuses are pretty easy, pretty reliable things.

You know they they blow around. That stated uh power level right if it says five amps around five amps it'll blow. So now we're coming up to four minutes and it's still there look the hottest thing on this uh image. Here, it's still 30c i'd say: that's pretty stable.

Now right, it's it's four minutes in this camera and then it would run another like two three minutes. I think off camera with the other camera i'd say i'd say: let's bump it up bump it up, let's bump it to. Let me bump it too, by the way the cells are, at this rate, they're there's about no a bit lower than nominal now. Actually, this is a small battery, so i kind of have to hurry up and do this before the battery runs out.

Okay, so here we go seven and a half: let's try it seven and a half. Let's see if we see heat, building up seven and a half, the cells are going down to 3.5, okay, okay and now we start to see parts of this image go to 31 right, so one degree increa increment, you know increased yeah and and is that accurate, Like the the heat is there or the i mean that image right. Obviously, it's wondering and yeah, because you see kind of the middle ones are seem like they're, hotter, they're they're blowing brighter right, hey, don't turn off. Oh 10..

This thing says that we're pulling 10 amps so that fuse might blow it's pulling 10 amps right now. What are we doing here? Oh 36, yes, see so now we're and that fuse you see that fuse starting to glow. That fuse is about to blow. I bet i'm not gon na intervene, i'm going to let it play out here.

Let me see 10 amps 10 amps. Why did it go to 10 amps? I don't know. Is it because the cells went lower yeah? I think because of the uh the voltage started. Dropping okay, so now it's going yeah just around 10 amps can okay.

So so something is 40. But what is 40? Let's see here. These are 38. That's 40..

The fuse is 40., but you know if we put like a 15 amp fuse or a 12 amp fuse in there. Then it'll run a little bit cooler, but these contacts obviously 40.. Okay, there we go, let's uh, let it play out play out. Oh man, my thing turned off come on.

Okay, i'm gon na have to restart my okay dc seared out voltage is 3.3, so it keeps going down the uh amperage power level. Yes, 9.5. Now so it seems to be going down the load into that board there. I don't know i'd say: can these do 10 amps i mean these are 40c, doesn't feel hot at all with the with your hands, so this might be 10 amp boards, which would make them slightly more than 1c right, because these cells have uh 5 amp hours.

What are what are typical? 21. 7. 70S. Have i don't know something like that? I think some of them are like five amp hours.

Well, that would be actually two seeded um, but aren't some going all the way up to like six amp hours? Well, okay, so just above just below to see like one and a half c's or something so here's the the way this test is working right. This is a continuous load test and we're essentially loading this battery up with two c's right now right. So i think these are 4.8 amp hours and we'll load them with 10 amps, so that's 2c load onto the battery. So that means that the the cells theoretically will cannot last more than half an hour right.

Um, plus, you know like minus losses and stuff will mean that they're going to well they're, just gon na they're gon na and run out of energy quicker than in half hour and now we're you know in this camera, 10 plus another two three minutes you know So we're 13 so we're about half ways to do this test right now. Uh yep and the voltage would agree with that. 3.2 volts still uh the batteries. The cells are staying, pretty balanced, we're not seeing that uh thing that we sometimes see on these, where the first cell, the cells on the edges, right the most positive and the most negative are the ones that are the lowest voltage.

Sometimes that happens when you, when you design a circuit and uh the two cells on the edges closers to the terminals. Those are the ones that suffer the most and see the most um stress, but it doesn't seem to be the case here. In fact, they are not the lowest cells right there there's some in the middle that are lower lower and that might be because uh differences in the uh, oh okay, these cells are warm now. What does the thing say? 44.

What's 44, though so 44 is the widest things in there is. That is that it? Ah that thing right there, okay, so we will uh as soon as the the batteries run out. Yeah so see the batteries are running a bit hot, but i mean we're halfway through that thing. Right, like 12 minutes, i i'm not measuring uh capacity out right now, but i'm just you know, calculating dude according to the time here, right, uh, nine amps right now.

That's what we're doing nine amps, so i guess i'm gon na have to decide if i want to play it safe and uh, like maybe rate these at seven and a half, there's a seven and a half fuse. I don't think there's like an eight fuse, or maybe there is. If i look for it i guess um, but i know we have fives. We have tens, seven and a half, so that's the one in between right, so maybe 10 is, would be a bit on the dangerous side.

I don't know. Maybe we could, i think, about what i'm gon na do. Is i'm gon na run this test with, like all five boards and then see how that does so that yeah, oh man, that means i'm gon na have to load this with, like 50 amps continues yeah. I want to do um a test with the five of these, because maybe this board that i we have here on the table.

It's an anomaly, you know it's, it's like a weird one that can handle the heat better. You know it has better for some reason. Just for a random thing, you know, but so now we, if we do this test five times, then at least now we have um more data right uh to be able to to make that decision. If, if this is how most of these boards are going to behave, so your sample size is too small when you only do one, so you want to increase that a tiny bit right, just to make sure that you don't get a weird one all right.

So here's the next setup i've connected four of these boards together now uh. This is a much better, bigger inverter about up to 1000 watts. So i think it's like 30 amps uh, which will load these up to about seven and a half right continues there. So, let's see if we could do this and nothing blows up, i haven't turned that thing on in a while.

So, okay, it's blinking, three amps, four on five amps: six: seven, eight, nine, ten, thirteen eighteen twenty uh! Oh, i only have it on the 20. okay. So we blew uh okay, so the the fuses blew okay. So i was about to reach over here and then i heard the crackling.

So i wonder why? Why did the fuses blow? So? Oh, that's why? Because these are fused at five amps and uh. That means anything over 20 amps. The fuse is blue, oh yeah, so i got changes. That's why? Okay, all right! Let's change those and reshoot this test! All right! Now we have uh 10 amp fuses, so this should be able to do 40.

Amps continuous - and this should be somewhere around 30 amp uh load right here. So let's turn it on. We just reset this and put it to 200 amps. So here we go there.

We go 25. 26. 27. 28.

29. 30. 31. There we go 31.

So about seven and a half uh amps per board. Oh it's going down! Oh! It's! Going up! It's going down! It's going down a little bit! So it's load up quite a bit on those cells right on the battery they're uh 3.7. There we go. Let's see we'll wait, we'll wait a few minutes and then we'll put the the thermal camera in here to see uh four of those boards in there and how the how those contacts are right, those should be about the same thing should be somewhere around 38.

Maybe right upper 30s c temperature wise and if they're all around there, then yeah, it's kind of uh matches our results of that first single board that we did right 28. It's going down a little bit. I think it's going down because of the voltage sag it's at 25, yeah 25.7 volts here are all the five amp fuses blown all right. So here's the heat signature from all the four boards 38.

Look at that, didn't i say 38 or the upper upper 30s. Those are the hottest things and it's it's just fuses really, but there you go. I think i'm going uh yeah, i'm gon na rape, these guys at seven and a half amps, because there's a fuse and at that temperature look at that. It's they run kind of cool in there, although right now they're only running around seven because of the for some reason, the the load is down to 25 instead of 30 right, so we kind of lost 5 amps there.

So all right, so here we go. This is the test we finished it uh we have tested now that this system can handle about seven and a half amps without getting too hot without melting, anything right and so we're gon na change that in the file. That's the only thing that we have left to do is to update the file change the text in there uh and then that stuff right. So this is the only way that you, you really know how to rate your uh a system right, and so, if you want to use this system uh you, i guess i'm gon na order some boards and then you stock, some in our store or whatever.

But if you wan na pay the least amount, you know it's an open source project, so you could just go to uh. Well, there are the sponsor, for this project is pcbway.com right and i will put a link on the bottom description of this video uh with our you can download the the files and you can order the boards from them and then have links to all the other Components the holders, the you know all the stuff and there you go if you want to see another test that i'm working on this is a 6 000 wide, a load that i'm working on. So i can test this battery right here and i've already been doing some tests, but i the lastest i've been, you know, i'm doing incrementally right. I want to load it with 300 amps.

Now i'm going for 500 amps to see how hot this gets and uh and then you know change. Take these just slightly optimize it. So it can run the most amount of amps uh through this, because these this cells can put out quite a bit like over a thousand probably close to two thousand eight amps, so anyways. If you wan na see me do that test and you know burn melt.

Some cables uh some pcbs or you know uh murder. Some inverters then stay tuned for that video. That's coming up in the next couple days, uh other than that. Thank you for watching these videos.

I will see you guys on the next one. Bye.