All right today's battery video is going to be an update on tax little 12s. We made a board to replace the proprietary uh bms board, that's on them right and today we got them so we're gon na see if we can install it in there and make it work right. So here are the batteries in question. Remember, there's two sizes: there are both 12 s and they have this board in here right and we don't know, there's not enough of these ones to really dig in there, at least for me, really dig in there and try to figure this thing out and hack.

It and you know, write the software to be able to access it all that stuff uh. If we had truckloads of these, then i'd say we we would do it. I would you know, send one of these to uh our. You know people that i know that know about doing this stuff, so what i suggested was for us to make just a quick breakout board, something that we can.

This is really easy to remove. All you have to do is desolder these uh points right here and then the board comes out, it's got screws right, and so all you have to do is unscrew it, and so we made it. I measured it. I measured the board and then i redrew it, and this is a supposed to be a replacement, and this is just a simple breakout board.

It just connects everything to this connector here and then it connects it here. So it's just easy to have two connectors. One is for the bms, the other one is just for power out, and here it is now, let's see if it fits. Ah, it doesn't fit.

There's see that's the thing about these. Is that, well, you can very easily make a mistake, one okay. So the first mistake is here: this is not wide enough. Well, actually, you know what this board right here doesn't go all the way to the edges.

So i guess it is okay. Oh i have this backwards. Oh i have this backwards hold on. Maybe it does fit okay, so look i just got the holes are just a little bit off.

This is a guide pin and then this guide pin doesn't want to go in there. That seems to be a little bit off. If some see can i put this guide pen yeah see well, this guy pin works, but then i think the distance between these holes is not perfect. Um, it's just a bit off, so i can go in the program right now and we could adjust this.

In fact, let's do that right now and then i'll show you what, because i noticed that a few of you guys downloaded the gerber file for this, and so now you're gon na get some of these boards that that don't fit perfectly right. So all you have to do is just make these holes slightly bigger and it'll fit in there, like the the actual dimensions that we got wrong here are is they're just slightly off yeah. This one is a little bit off. If, if you move it a little bit that way, then these will fit, but then yeah and then we just make these two bigger these three we'll just drill them bigger and then it'll fit in there.

Let me see, can i do that yeah so, basically to fix it, make this hole bigger and these three holes bigger and then it'll lay in there? In fact, let's try that right now? Okay, so how did i get this wrong man? I think i was using that caliper. You know what i did use that caliper at home. That was just a bit off um. So the problem is that i got this board just slightly smaller here we go it's not much, but it's just a tiny bit.

The thing is that it accentuates that problem, because here's the other mistake, so this whole side seems to be that on. Like you know, i measure from the edge and then what i did is then i just measure from the edge of this thing right and instead of measuring from here all the way up here like up and put that dimension in there i would have. I would have caught the the fact that this is smaller um. What i did is i just measured from the edge, and even that, though, see if well even that i got it slightly wrong because look at that that one's just a bit off that one will work.

This one is good, but um yeah, it's just like the mechanical's hard like you have to well, you have to have a caliper. That is not bad. You know the problem is with my caliper. Is that it's one of those electronic ones and the battery runs out? Those things suck the batteries are always running out and then and i'm trying to use it without the battery.

So i'm trying to read what the thing, but it doesn't have a mark right. So maybe i'm reading like one millimeter or half a millimeter off and then that's what i'm trying to, and so it took a while or a few of these to to for me to be able to realize. Like you know what this caliper, i can't use that caliper like that. So i have another one: that's manual here and see those these are the problems.

This wouldn't be this bad, i think, had i used a proper caliper. I hate those stupid ones with the batteries because it's like the stupid and even that see it's a little bit off that one, no, that one's dead that one's right there. These are off a little bit this way, and this dimension too, but see it's crazy, because it's only these two that are off this way: okay, how to fix it. Let's drill these holes bigger and then see we can put it in the thing and then make it work.

Okay, here we go now we um install the uh xd60 connector and then the little idc connector right. So now it's there. So now we just have to solder these all right. So now that we have this assembled uh, the pads are also a bit off, but we'll fix that right on the file.

What can you do with this now that it's all like this? Well, this connector right here you can connect your bms here right and then you can connect this into the negative into the bms and stuff and you'll need one of these connectors, a 16 idc connector. These are connectors that we use on all our other boards and stuff. So i made a little cable here: it's not perfect um, because uh there's one cell that is missing there from going from one to the other. So i have to put a negative from one to the other one, but it works.

Basically, it allows you to then check the cells there. So there are seven cells here, they're pretty balanced, and then there are the other four cells and there should be five cells. But there's one cell: that's between the negatives on one, the this side and the positives on that side. So that's why there's no talk? All you have to do is put one cable jump it from here right when you're making your your special cable um.

But that's it um, i'm going to charge this and then i'm going to discharge it uh just to show it working and then we'll put the thermal camera here to see how this board does. It's got a big giant trace in the middle here and then all the other ones kind of zigzag right. So let's check it out. Okay, so i'm going to charge that here using this, this is a uh top voltage on a 12s right times, uh 4.2 right 12 times 4.2 is like 50.4.

This thing only goes up to 50 volts, so that's, okay, we'll just charge it right. So here we go we're gon na put two three. This is what two cells right um. This is about seven, let's do five amps, that's still below one c, or should we do one c? Let's do one c, okay, so one c charging.

I know that's a bit fast, but uh just for the sake of time right. Let's, let's charge it the you don't want to charge your batteries that fast, that's like a one hour charge uh, but cars. Do it all the time right now? Of course they do it with cooling systems and stuff, but this is just a little battery and i'm gon na monitor here, um, while uh and also we're gon na, be monitoring the cells to make sure that not one of them goes crazy, um. While that happens.

Let's go to the software so that we can make all the changes uh to make this perfect and then we'll update the saw the file in the uh project right, and so that way this will fit perfect when you get it and stuff and you do it And look i don't know, i know these are a small number of these by the way we just found a few more um on our on our palette there, and so we're gon na list those today. So, if you're watching this today, when this video airs there's a few more of these packs that are available on the link down in the description um, but here's the thing we might get more in the future. If that's the case, then this is going to become real uh useful right for you, guys that buy these packs and you guys want to use them for your own diy purposes right. If not, then this is a good exercise on how to design a pcb breakout board like this.

For you know a battery that has a custom, uh, electronics, sort of like this and then they're either too hard or not worth you know, trying to hack, because that's a lot of work right uh for someone it might be easy, but for the general public, like Regular people like me - and you probably watching this video - this is a lot of work, and so you know you need specialized equipment specialized knowledge, and so this is a lot easier to do so, let's go to the software and then fix all the little issues that This thing has okay, so issue number one is see these numbers right here. We need to move those further apart because they're not as legible right. This thing is smaller than the actual connector. So let's do that.

Okay! The next thing is the width of the board. According to this, the original board is about 62 millimeters and the board that we made is 61., so there's a difference of one millimeter, but that's that's enough to uh make a difference here. So, let's, let's bump up to 62 millimeters, okay. So the next thing you see how these screw holes they match, but these pads don't that one's just a little bit.

This way, this one's a little bit this way this one's a little bit, so i just need to grab all those pads and move them um, and i need it seems to be getting worse towards the end over here yeah it seems to. But if i just move them all i'll measure this and then move them uh, let's see here what how much do we need to move them so about six millimeters? According to this six millimeters, i'm just gon na move everything six millimeters that way. Okay. So now this one right here, which is the first one that needs to move up - and i guess what i really should be doing - is measuring from here to there, but it's harder because then you have to do an angle like this.

Well, what, if you do that? Well, i guess you could do that or to the edge over here and then that gives you center to center huh. Let's do that? Let's see, let's see if that works out, so that is going to be uh. 5567. Exactly 57 millimeters from center to center right center to center, okay.

Next, what i need to do is, according to this, this one needs to be moved this way right. This one has to move that way. This one has to be moved that way because you could see there. Actually you can't even see it on the camera, but oh here we go when you put it there like that, you see them right and then also these pads have to be moved this way.

Okay, so also the board can be longer to match the original one. I don't know why that ended up being shorter, but that's like three millimeters too short, so i'm gon na extend that also the uh. The trace fuses here can be thicker, so i'm gon na thicken all those up uh just so they can handle more more current right, although they're just sense leads uh, but your bms might want to balance at like one or two amps or something. So then, that could carry that without the risk of them, because they're they're super thin here so yeah.

Let's increase that all right, so here's our test. I have connected this battery. It's at 50 volts right. So it's fully charged connected to this uh 1000 watt.

Uh ac grid tie inverter right, so here we go 49 48.9, so 49 volts uh it might pull about 30 amps we'll see that'll be enough to see. I think the cells can handle 30 amps, it's a 2 that'd be 15.. Each one is three whoa, maybe not maybe that's gon na be a lot. I think 30.

I think it's it'll it'll pull about 20 some amps. I think right because i think at 50 uh, if you do the math, i think we'll we'll see how it does. But i think what happened is that it's going to get hot we're going to push this battery right uh to its limits, uh and i think the cells are going to get hot the the little. I think everything else is gon na get hot.

I don't, i don't think the board particularly is gon na, be the one that gets the hottest here, but this is why you do these tests. Let's do it so now we just plug this guy. Now it's gon na pull about 15 amps. Oh yeah! Look at that 16 amps, so 700 watts yeah, that's it okay! So okay, look at the cells.

I guess there is uh cell number. One group number one: it's a bit weak! So it's uh! You know there we go so it's pulling 16 amps. Let's pull more than that, let me see if i can set it okay, so i just sent it set it to 20, so we'll see what it does. At 20., there we go 400.

700, so it's 700 watts, 21 amps uh there. It is group number one! So let's put the thermal camera see. Oh my god, you see that those are the uh. That's the exit points, the two exit points and then the cells themselves are getting hot right.

The two exit points are gon na get hot, because that's that tiny i mean. That's kind of small uh nickel strip right, so maybe that nickel strip is not gon na, be up to the task of uh doing 20 amps. The cells themselves are getting hot, so it's 800 watts right now. That's what we're pulling off of this little battery, and this is the little battery the one that it's only got: uh 12, what 24 cells right, 24 cells, so only two cells in uh parallel, so two yeah, so each each cell is uh given about you know.

Ten point something: uh amps yeah, ten, ten and a half amps. Basically, that's! Oh! So what are? What is the temperature there? That's the hottest one right there 37 that right there has the shortest uh travel to the connector right, the that one over there. On that side, that one has the longest travel. I mean it's like this whole pad right here has two transmit the the 20 amps all the across the thing right, but that's a pretty big pad uh well trace right.

It's like almost the entire board on that. One side is just copper pad right so and, as you can see here, everything else is getting hot, but the board right. It's the nickel strips the cells are getting hot, but the board is doing fine. The board can handle probably 50 amps okay, so there are cells, that's that band, that's the heater and then the cell, so the cells are running hot.

Look at that, oh 50 yeah. So the cells are getting hot, all right. There we go so this board is more than capable of doing the max on this little battery right. The battery can't push more than 20 amp continuous, so this board can uh and, according to our temperatures here, it'll do something over 40..

So i'm gon na make the changes uh to make it beefier uh in the parts that are getting hot here and then i'm gon na update that file right. I'm gon na update that file on the project so that anyone that downloads it from here on is going to have all the changes, the mechanical changes and also the electrical changes. And then i'm going to order another uh, i'm going to order another sample and then we'll do the large battery here and then we can push that one. Because look i mean we push 20.

40. 60.. So we'll see if we can pull 60 amps off of this one through that board right, but it will have to have those little changes uh and we will see how hot it gets right. Um, obviously, 60, the cells are gon na get very hot yeah.

Just the same way that it got here, so i think the maximum that you can safely do on this uh pack right here, it's about 50 amps right, so i've run 60 amps through boards before uh. It's just not that particular so i'll be able to optimize that so that it we can run 50 amps through this one right here and it'll, be i'll update it and so yeah as soon as uh, probably tomorrow or whatever we'll be able to you'll, be able To download the updated version that can handle 60 amps, 60 amps uh, so that yeah, so that you can have these batteries right and if we get more of these, this is our very going to be very useful and, if not like, i said it's just a Good exercise in designing a printed circuit board for battery uh, and then you know i'm showing that, because i want to share my knowledge, the little stuff that i'm learning here, how to do this stuff. So if you find this useful and if you want to start printing your own boards and designing your own boards now you have a an idea of what it is that it takes to do that right. This is uh.

It takes a few tries you order the one and then you get all the mistakes out. Then you fix some mistakes and then you order a second one and then even the second one you might be like. Oh, i should have done this other thing this way, but after two three tries or whatever, then you got the final one that fits perfect and then it can handle all the power uh and that it's got the right connectors and the right everything right. So this is how it goes right and then you can share your own designs and stuff and you can order them on the on our sponsor our channel sponsor right.

I don't do a lot of sponsorships on this channel only a few here and there and uh pcv way it's one of those that it made sense, because i'm designing so many boards and so they're helping us by creating good service and you being able to share The uh creating a place where you can share all these files and stuff right. So all right! Thank you for watching this video we'll see you guys on the next one bye.

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