DIY Rapid Build 18650 PowerWall Module project - design & testing

would it be great to just be able to put batteries together just like the old times like our ol remotes you know like this that's how you that's how you install it well as far as I know there isn't but can we just make something oh yeah I think we can the DIY power walls movement is an ever growing phenomenon projects are being built all over the world and a lot of them are amazing traditionally the biggest hurdle was finding good sources of battery cells new cells were prohibitively expensive and the only decent deals were found in China where there were huge risk in order and expensive products and having to wait long times to get them but within the last year or so sources of batteries in the USA that traditionally would ship their product to China for processing have realized that there's a new market in the DIY crowd and as a result of that every day we are finding more and more sources of use and overstock lithium battery sells locally that means that the second biggest hurdle in the DIY battery build is the assembly of all those little cells into one big battery system capable of powering your home up until now that the fact the way of doing this has been to borrow technology from the ebike industry and the adoption of these cell holders and tech from Tesla in the cell level fusing we started soldering everything together and now we're moving into spot welding which is faster but it's still an incredibly labor-intensive project a lot of people in the community started using these types of holders mostly to set up charging and testing rigs or many cells have to be installed and removed frequently the one person has actually used them to build his large battery pack so I started thinking could I design a system or a regular person following a set of instructions get easily and affordably hundreds or thousands of cells into a large battery pack there is only one way to find out so I started by sketching a PCB design on a napkin at that point I realized that I don't know how to use PCB design software and I don't know if I have the time to learn so I put out a call to see if anyone out there would help and soon Justin appeared and offered to help a few e-mails back and forth and bam just like that we got Sam oak right so here is the board I would say this is the backside no this is the back side this is the front side which means that the front side is the one that has these guys the holders it's got markings cell positive cells negative you can read them they're kind of small but here says so negative and then so positive these also have markings I like to use the ones that are inside the little bubble I like to use those because they're more visible and so it's less chance of you getting them wrong right so these are the positive sides and these are the positive sides that means that this board goes like this okay one thing to note is that there is slight space there's slightly more space between this pin and that pin than all the other ones right this is set distance between all these pins here but because we're doing is a 7 s we're gonna have to use a 4 Bay holder and a 3 bar and so in order for them to fit without any interference then what we did here is we added more so that means the way this is design is to have the 3 Bay closer to where the xt60 connectors and all the other terminals are and the four Bay on the bottom where these holes are at that don't have any electric connections and then the other thing is to keep in mind that this is the positive positive side so I have this one Hong and flip it around come on there we go so this is the positive side one 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 the bubbles go on this side flip it around and then you solder this next thing is we're gonna start at this little pin here you're gonna want to install it in the backside what you're gonna want to do is make sure this is straight right now 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 these this is kind of fine work here you don't want to create big blobs of solder and then finally what we need to do is installed the the main surface mount fuse there right if you don't want to buy a fuse then what you can do is use a regular 1/8 watt resistor right and then what we do is we solder here this side you start at that side then we get the resistor here and then we just there we go that's one side and there's the other side this side over here a little bit more there we go so that forward is now done right here's the second there are all four of these modules that I'm gonna use I only put the xc60 on the one because that's gonna be the end right and so now we just gotta load up the battery similar so make sure that you're not these two posts are not touching anything because these are electrified make sure all your batteries are the same voltage I recommend you throwing them on the charger and then charging them all the way up to 4.2 because then that way you know they're all exactly the same voltage because if they didn't they're not if you run into the risk of the blowing up the fuses here these are the traced fuses that are for all the balance leads right so it's a cell it's unbalanced so if any of the cells is not the same voltage the other ones then the other all the other ones are gonna try and charge it using these leads here and then Fitz and if the imbalance is too much then basically this might blow up here we go here some brand new cells back to thousand milliamp hour piece I'm gonna use these as a test positive all positives going outside all natives on that side now when doing this for the very first time make sure that you pay attention and then you know you you can touch the cells you can touch this stuff to see that everything is correctly at this point I recommend checking the voltage look at that 27 volt here's a connector that I made a little dongle for one of these cell log eights you can just connect it in here and then you should be able to see the voltage of every one of these cells there we go they're pretty good 22 millivolt difference between the high and the lowest okay let's build a next one 2769 stack these two together then those don't really touch so you'll need an extra one of these guys stick it on here make sure you don't bend those and touch them because then they're gonna short out there we go we put another then let's do the backside here [Music] right they just went in there last thing we do here install the screws 20 76123 millivolts difference so there we go this is an 8 amp hour right this is an 8 amp hour battery pack 2 plus 2 plus 2 plus 2 2 4 6 8 right and all of these cells right here cell number 1 they're all connected through these little pins here and then you can see it on this little thing here this is a 24 volt pack right if you want to run a 48 volt system then you would do two of these in series right you would go from the negative to the positive of another one of these and then that's how you would do the 48 volt packs they have to connect your BMS you just do it right here here are the eight leads for the seven cells and then here are the two main ones you would put the negative through a thing if you think that's you know if you wanted to use one of the smaller one ebike type of BMS if you want to do bait reom that's the other thing you would also put it right here now let's test it let's put a load in here alright here's my setup here's the battery that I just built a town powers right it's almost fully charged three point nine that's where the cells are at right now this is going through this meter right that gives you all the info amps and Watts and stuff and then that's going to a 24 volt 1200 watt inverter start there we go okay six amps 162 watts yep you know there's there's nothing happening here it's nothing there let's let's start up the other light boom okay so now I'm at 12 amps so I'm loading it up to 12 amps and look at that oh yeah I start to see these are the conductors here all right you see that with my fingers at least each one of these is where the connections to the batteries are gonna get either going out a hundred degrees 12 amps 300 watts that's what we're loading up this battery with the cells are sagging a bit 3.5 so there are around 3.5 right now all right let's see here let's look at the fuses so the fuse is right here with my fingers at that's not hot at all alright that 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 one of those is not seen a lot okay so those are 106 108 so this is 10 degrees above ambient so these are what's gonna determine how much we can load up these type of modules okay we're doing 400 12 watts seventeen and a half amps the batteries are sagging down to three point three right at 400 watts so we're doing to see this is to see this is probably where the cells are rated you wouldn't want to go much more than this anyways 122 Fahrenheit how many amps is that so that's 18 amps 9 amps right so 4 and a half wax so each one of these contacts right here right now it's seen its 18 amps but the total the Paxil each each one of these contacts should be seen about four and a half amps less than five amps and the temperatures getting up to 126 now where it's safe for that plastic right before it starts like melting and stuff I don't know so 126 degrees is it's warm it's warm to touch 10:27 18.1 amps there we go 400 watts all right so we're getting near 130 degrees let's see if defuse you gotta fuses doing nothing fuses right here where my fingers at right here it's not even one I'd say yeah I say if it goes above 150 degrees and then it's not good I think that's probably when this plastic will start melting yeah 140 look at that it's reaching 140 of course over here they're creating massive heat to give this 293 degrees oh my god I'm melting my thing don't know my floor so it's pretty clear that these plastic holders are the weak link in this design at 4 amps the cell terminal contacts reach around a 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 assembly is capable of around a hundred Watts peak or better yet each assembly is capable of one C continuous and to see peak this would be a problem if these were designed for anything other than large firewall applications they are not don't use these on ebikes or any other application that will require more than one C continuous out of your cells obviously there's still more testing to be done on these I will build a larger pack around 5 kilowatt hours and we'll test these both at 24 volts and 48 volt configurations as far as costs well it looks like each assembly will cost around 4 to 5 dollars which is about what most of you guys are already paying for the ebike type of holders and soldering and spot welding materials but hopefully my build will show that it will be far easier and quicker to build large battery packs using 8 650 cells using this system to stay tuned for future videos on this project and with that I say thank you for watching these videos but before I go make sure and check out my new line of merch the recently added three new shirt designs like the Eevee outpost one the e samba project finally got a shirt and even this rapid 18 650 module project has its own shirt please check them out and if you'd like to support this channel by wearing some of these I will forever be grateful also one more thing I currently spent a couple hours trying to answer all the questions and comments that I get across all my social media accounts unfortunately that's not enough time and a lot of your messages go on answered especially all the ones that require a lengthy response from me for that reason I have joined a new service called fan time it allows you to buy 101 video chat with me to discuss your projects in detail I will try to set up half our slots during the weekdays for anyone interested and with that I say until next video bye [Applause] [Music]

Channel: jehugarcia

Views: 812,234

Keywords: lumix, diy, renewable energy, renewable, li-ion, lithium, ion, battery, tesla battery, powerwall, solar, 18650, dead battery, TESLA

Id: 9YwErplHps8

Length: 18min 32sec (1112 seconds)

Published: Tue Jul 10 2018