DIY Rapid Build 18650 PowerWall Module project - design & testing

Would it be cool to be able to put the batteries together like in the old days, like our old remote controls? You know, that's how it's installed well, as far as I know there isn't one, but can we do something? yes I think we can, the DIY electric wall movement is a growing phenomenon. Projects are being built all over the world and many of them are amazing. Traditionally, the biggest hurdle was finding good sources of battery cells. The new cells were prohibitively expensive and the only ones decent. Deals were found in China, where there was a big risk in ordering expensive products and having to wait a long time to get them, but in the last year, battery sources in the US that would traditionally send their products to China for processing have realized that there is a new market in the DIY world and, as a result of that, every day we find more and more sources of use and an excess of sales of lithium batteries locally means that the second biggest obstacle In DIY battery

build

ing is the assembly of all those little ones. cells into a large battery system capable of powering your home until now the way to do that has been to borrow technology from the electric bike industry and adopt these cell holders and technology from Tesla in fusion at the cell level We start welding. all together and now we are moving towards spot welding which is faster but still a labor intensive

project

.

Many people in the community started using these types of brackets mainly to set up charging and

testing

platforms or many cells have to be installed and removed frequently, one person has actually used them to

build

his large battery pack, so I started Think: Could you

design

a system or could a normal person, by following a set of instructions, easily and affordably get hundreds or thousands of cells in a large battery pack? It's just one way to find out, so I started by drawing a PCB layout on a napkin, at that moment I realized that I don't know how to use PCB

design

software and I don't know if I have time to learn, so I made a I called to see if anyone could help and soon Justin showed up and offered to help with some emails back and forth and bam, just like that, we have Sam Oak, so here's the board.

I would say this is the back. no, this is the back, this is the front, which means the front is the one with these guys, the brackets, it has markings, positive cells, negative cells, you can read them, they're a little small, but here says negative and then. Very positive, these also have markings. I like to use the ones inside the little bubble. I like to use them because they are more visible and there is less chance of you making a mistake. These are the positive sides. positive sides, that means this board is like this, okay, one thing to note is that there is a slight gap, there is a little more space between this pin and that pin than all the others, right, here the distance between all these pins, but because what we are doing is a 7s, we are going to have to use a 4 bay bracket and a 3 bay and, in order for them to fit together without any interference, what we did here is add more, meaning the way this layout is to have the 3 bays closest to where the xt60 connectors and all the other terminals are and the four bays at the bottom where these holes are that have no electrical connections and then the other thing is keep in mind that this is the positive side so I have this Hong and I turn it around, come on, come on, so this is the positive side.

A quick way to tell is that this is the positive terminal here, so all the positives inside the little bubbles go on that side. and all the negatives and bubbles go on this side, flip it over and then solder it. The next thing is we're going to start with this little pin here, you're going to want to install it on the back, what are you going to want? What you need to do is make sure that this is straight right now, that it's at an angle like that, so you use xt60 connectors and then it's straight.

Another important thing is to have a small tip because this is a good job here, you don't want to create big blobs of solder and finally what we need to do is install the main surface mount fuse right there, if you don't want to buy a fuse then what you can do is use a normal 1/8 watt resistor and then what we do is we solder here on this side, you start on that side, then we get the resistor here and then we just there we go, that's one side and There is the other side, this side here a little more, let's go so that the progress is already made. here is the second one, there are four

module

s that I am going to use.

I only put the xc60 on one because that will be the end so now we just have to charge the battery similarly so make sure you are No, these two poles don't touch anything because they are electrified. Make sure all your batteries are the same voltage. I recommend that you put them in the charger and then charge them up to 4.2 because then you will know that they are all there exactly. the same voltage because if they didn't, they're not, if you run the risk of blowing the fuses here, these are the traced fuses that are for all the balance wires, so it's a cell that's unbalanced, so that if any of the cells don't have the same voltage the others then the others everyone else will try to charge it using these cables here and then Fitz and if the imbalance is too much then basically this could explode here we go here some new cells Back to the piece of one thousand milliamp hours.

I'm going to use these as proof positive. All the positives go outside. All the natives on that side. Now when you do this for the first time, make sure you pay attention and then you'll know that you can touch the cells. you can touch these things to see that everything is correct at this point. I recommend checking the voltage. Look at those 27 volts. Here's a connector I made as a little dongle for one of these cell recording eights. You can just plug it in here and then We should be able to see the voltage of each of these cells, there we go, they're pretty good.

A 22 millivolt difference between the highest and lowest, okay, let's build a next one. 2769 we stack these two together and then they don't touch, so I'm going to need an extra one of these guys, stick it here, make sure you don't bend them and touch them because then they'll fall short, come on, let's put another one in and then do the back here, they just went in there . The last thing we do here is install the screws. 20 76123 millivolts difference, so there we go. This is an 8 amp hour battery. This is an 8 amp hour battery pack. 2 plus 2 plus 2 plus 2 2 4 6 8 correct and all these cells here.

Cell number 1 is connected through these little pins here and then you can see it on this little thing here. This is a 24 volt pack. If you want to run a 48 volt system then you would do two of these in series. you would go from the negative to the positive of another one of these and this is how you would make the 48 volt packs that they have to connect your BMS, just do it here, here are the eight wires for the seven cells and then here are the two main ones, you would put the negative in one thing if you think that's what you know, if you wanted to use one of the smaller types of e-bike BMS, if you want to make a bait, that's the other thing, you would put that in here too. now let's try it, let's put a load in here, okay, here's my setup, here's the battery I just built, a city has power, it's almost fully charged, three point nine, that's where the cells are right now, this is going through this meter, that's what gives you all the information about amps and watts and stuff, and then that goes to a 24 volt, 1200 watt inverter, start there, come on, okay, six amps, 162 watts, yeah, you know, nothing's happening here, nothing's happening, let's start with the other light arm, okay, now I'm at 12 amps, so I'm charging it up to 12 amps and look at that, oh yeah, I'm starting to see that these are the conductors here, okay, you see that with my fingers at least each of these is where the connections are. the batteries are going to discharge a hundred degrees 12 amps 300 watts that's what we're charging this battery with the cells are sunken a little bit 3.5 so there's about 3.5 right now okay let's see here let's look at the fuses so the fuse It's right here with my fingers, that's not hot at all, well, it can handle 12 amps, no problem, well, it's not 12 amps, 13 amps divided by four, I guess, so it's not much, each of those doesn't looks a lot okay so that's 106 108 so this is 10 degrees above ambient so this is what's going to determine how much we can charge these types of

module

s okay we're doing 400 12 watts seventeen amps and a half, the batteries are going down to three point three right at 400 watts, so what we're doing to see this is to see that this is probably where the cells are rated, you wouldn't want to go much higher than this anyway 122 Fahrenheit how many amps are they?

So it's 18 amps 9 amps, so 4 and a half wax, so each of these contacts here right now is 18 amps, but the total of the Paxil, each of these contacts, should look like about four and a half amps. , less than five amps and temperatures rise to 126 now. where it's safe for that plastic right before it starts to melt and stuff, I don't know, so 126 degrees is warm, it's warm to the touch 10:27 18.1 amps, there we go, 400 watts, so we're off. approaching 130 degrees. see if you disable, you have to merge, do nothing, it merges here where my fingers are here, it's not even one.

I would say yes. I say if it exceeds 150 degrees and then it is not good. I think that's probably when this plastic will start to melt. Yeah 140 look it's getting to 140 of course they're creating massive heat here to give this 293 degrees oh my gosh I'm melting my thing I don't know my floor so it's pretty clear these plastic stands are the weak link in In this design, at 4 amps, the cell terminal contacts reach about one hundred and fifty degrees Fahrenheit, that's about 65 degrees Celsius for all you non-Americans. One way to look at it is that each set is capable of generating around a hundred peak watts or better yet each.

The assembly is capable of continuous C and to see the peak, this would be a problem if they were designed for anything other than large firewall applications. Do not use them on electric bicycles or any other application that requires more than a continuous C. of their cells, obviously, there are still more tests to be done on them. I will build a larger package of around 5 kilowatt hours and we will test them in 24 volt and 48 volt configurations as for cost it looks like each assembly will cost around 4 to 5 dollars which is about what most of you are already paying for e-bike mounts and soldering and spot welding materials, but I hope my build shows that it will be much easier and faster to build large battery packs using 8,650 cells. using this system to stay tuned for future videos about this

project

and with that I thank you for watching these videos, but before I go, be sure to check out my new product line, the three new t-shirt designs recently added, like the outpost of Eevee, the Samba project finally got a t-shirt and even this Rapid 18 650 module project has its own t-shirt, check them out and if you want to support this channel by wearing some of these, I will always be grateful too for one more thing I currently spent .

A couple of hours trying to answer all the questions and comments I receive on all my social media accounts is unfortunately not enough time and many of your messages remain answered, especially all the ones that require a long response from me, for that reason I have joined a new service called fan time that allows you to buy 101 video chat with me to discuss your projects in detail. I'll try to set up half of our spaces during the weekdays for anyone interested and with that I say until the next video, bye.