Build your own solar battery and save thousands $$$

inside this Treasure Chest are some of the highest quality lithium iron phosphate cells on the market today I would love to use them for my solar off-grid system to power my entire house when the sun doesn't shine but first we have to unbox them out of the crate unbox them out of their original Arrangement and then re-box them up into something that's more useful here we go [Music] hi I'm David and welcome to my channel where I'm on a mission to take my house and garage completely off grid over the last several years I've been building up the entire solar off-grid system I've got a great solar array in the backyard I've got an excellent high quality Schneider inverter on the wall and I've even got some Army generators to provide backup just in case we have long stretches without Sun but the part that is usually lacking is the energy storage the battery and that's because the battery can be the single most expensive component of the entire system when looking at home energy storage you typically have your choice between either buying the pre-built battery or diying and building your own I've tried both and both have the pros and cons when I've purchased some server rack style batteries they're great because they're ready to go right out of the box they're already tested and they work well but they cost about 300 per kilowatt hour when you build a DIY style battery you might be able to do it for about 150 dollars per kilowatt hour when you're done but your tip typically buying used cells that I've already spent a life like on the road in a car and they might be degraded they might not last as long but inside this this crate which we're about to take out there are some brand new cells and not just any these are the highest quality lithium-ion phosphate cells on the market today we will have to unbox them and then unbox them out of their Arrangement that they're currently in in order to reconfigure them to work for us but if we can do that we'll have something that will last a very long time and in the end I think I'm going to be able to do this for about half the cost of a pre-made server rack style battery or roughly a hundred and fifty dollars per kilowatt hour if we can pull this off it will be safer than 18650s or used electric car batteries and it's an excellent option to get a lot of kilowatt hours of storage for the least amount of money nice it's not just cardboard I got a plywood frame too backside looks like a pretty thick steel base that it's sitting on fairly thin plastic cover all of these are for air to vent through over here is the front I bet this fan is blowing in and then it pushes the air out past each cell these are each individual cell so these are 280 amp hour cells lithium-ion phosphate 3.2 volts each this assembly could have been used in some kind of really high amp application so the way this type of assembly works it does not have a true BMS or battery management system instead it has this which is a bmu or battery management unit it's collecting data and then sends that data up to some higher level computer which would have been one Central higher level computer for I don't know however many of these modules they'd have strung together so what that means is that we'll have to add our own BMS I don't know how these are attached yet but it's probably just a push in [Music] this is the simple forked tool that I'm using 3.292 3.292 oh my goodness wow oh that is perfect that doesn't get any better than that let's check our voltage for the whole pack 65.88 volts now down here at the front we probably don't have any voltage up here unless we were to attach the safety disconnect so let's find out yeah no voltage and let's see what happens if we put the safety disconnect in looks like it's going to go this direction nice and now let's check our voltage and 65.9 well before I start messing around with this too much I think I might take off this jumper on the rear see how it's attached I'm curious how much torque it's going to take to remove these so I guess that was 5.1 and let's try this one 5.2 so not very much torque [Music] there's the bmu [Music] before I continue dismantling the battery I'm going to remove these hold down brackets and the wood blocking that way it won't interfere with removing this front face coming off [Music] Phillips number three for the screws around the edge with hindsight I should have removed all of these little brackets and the wood blocks before doing anything else because right now I have the black plastic cover off from the top of this battery so oh well I'll do it on the next one next I want to remove this big front steel cover I see four screws along the bottom I also see four screws along the very top which kind of go through the steel cover this kind of aluminum bracket on the cells and go all the way down into the base so we have eight things to remove so it looks like this green plug up on the front face is just directly connected over to the Reed switch which would be in the safety disconnect yeah so it looks like the negative just has a straight shot directly to the negative amphenol connector and then the positive is the one that gets broken and I'm I'm making an assumption that these are amphenol connectors I don't know 100 it's just a guess so there's four bolts two at each end of the whole cell group so the 10s is a cell group and then these bolts are going all the way through into this the steel base the fan blows directly in here looks like they have some kind of little foam gasket the fan would blow in and then it could disperse out between each cell to help cool it I have taken off all the accessory components now we are left with just the cells breaking the battery down to this point was fairly quick and straightforward at this point before I can break it down any further we have to discuss what the plan is moving forward this whole pack is a 20s pack which means it's going to have a pretty high cell voltage each cell is 3.2 volts which means the entire package is about 64 volts nominal it needs at least 70 volts to charge it well that's really high and too high for most 48 volt equipment with a couple of exceptions out there but generally speaking we can't use this voltage it's too high the most common arrangement for this type of chemistry is to have 16 cells in series 16 cells in series gives you 51.2 volts nominal and charges really well with all the standard off-the-shelf 48 volt components so that's the arrangement that I want to put this into is 16 cells in series or we shorten that up to say 16s since we have 20 here I have to decide how to electrically disconnect four of the cells so what I could do is I could cut the jumper wire here and cut the jumper wire here and electrically disconnect the rear two cells from each cell group or do some other combination if I cut it right here then this 10 SL group can still use the original Factory jumper bar to jump between this cell group and this one I'll have 16 cells in series total and then I'll be left over with four cells without a dedicated purpose right away now in some applications you might want the 48 volt battery and then you might want the 12 volt left over for something else this might be I don't know a tiny house on Wheels maybe you got some 12 volt lights or maybe you have an off-grid property and you have some 12 volt accessories like maybe a 12 volt pressure pump or something and maybe you want that just left over as a 12 volt battery and that would be great just leave all this steel banding there's a steel banding at the top and another one at the bottom you could just leave the cells glued in place and you'd have your 48 volt battery for running your inverter and a separate 12 volt battery for some accessories now if you have the funds up front you could buy two crates which would be four modules now this is one crate that I have here with two modules but if you bought two crates four modules total you'd have four cells left over from each module that would give you another 48 volt battery on top of it so in that application you can purchase one heavy duty shelf of four shelves four modules but electrically I could connect the 4S group from here to the next shelf to the next shelf to the next shelf going up and create an extra 48 volt battery but that's not what I'm doing in this situation I want to try to remove these four cells I'm going to cut this plastic Raceway and the jumper I'll remove the steel banding and then we'll catch in again and see if there's a way that I can actually remove these four cells I'm not sure yet how I'm going to approach that because they're glued in place but we'll work on that together these multi-colored wires are going to be checking the voltages of each cell like right here it's tied to the cell bus bar but also there's a couple of temperature sensors in here I can't just simply cut this off because I will short all the wires to each other and you'd burn out the wires so instead we need to cut these one at a time remove them from the plug and I'm going to also remove this wrap here with the zip tie [Music] this is called liquid electrical tape and I've never tried this before but I'm just thinking it might help with some of the uh the loose wires here foreign [Music] the plugs are off on both ends and I have a little bit of that liquid electrical tape on there typically when I cut off plugs like that I go immediately to the BMS but since I need to remove this or at least I'm going to try to remove this right now I can't go directly to the BMS so I wanted to do that temporarily all right let's finish taking off some of these wires here go all right so I'll just keep working this back until we get to this point because one two three four I'm going to make my cut here so now these wires are secured with a zip tie we got a little bit of hot glue on there and all the wires for the back six cells they're off to the side one two three four and we'll cut it right here I'm just putting a piece of plastic in underneath this bus bar to help stop shavings from going down and I laid a piece of leather down here this is just a welding apron [Music] thank you [Music] at this point we have created two batteries we have this 48 volt battery and we have a 12 volt battery right here now all these cells are currently attached to the metal tray and they're glued down so they're in a really nice configuration if you could use them like this in my situation I want to see what it takes to remove these four cells and just leave the 16 cells left on this metal tray so I'm going to cut the banding and we'll see how well it's glued down maybe I can break free these four cells as a solid group I'm not sure but let's find out together [Music] notice that when I cut this it opened up but it didn't spring open and cause a lot of force and we didn't see the cells expand out my understanding is that you want to clamp the cells to hold them in place but you're not trying to compress the cells if these were under a lot of tension they would have sprung out so I'm going to try to duplicate that same thing when I re-fixture them after this foreign [Music] [Music] thank you [Music] so over here I need to add some form of new compression this could be done in a lot of different ways but I'm going to try re-banding this with a little banding kit that I bought on Amazon so let's start by looking at the end of the cell I removed all of the putty that was on here mostly using this plastic trim tool a couple of spots that look a little bit rougher that's where I used a metal tool to scrape away the rest of that putty I think it was some kind of thermally conductive putty because it's in between every layer but it was not really adhesive it wasn't really glued on the way that like a silicone might be so it was in between all of these layers including this plastic isolator so I'll put this plastic isolator back on I'm just pulling up this little plastic Raceway right now and we'll get that in place and now before I add the metal backing plate back on I'm going to give it a little bit of squishiness to it I don't have the same exact kind of thermal putty because I don't know exactly what they used for that if you do know exactly what this kind of putty is that I kind of scraped off and if I kind of you can see it's tears it doesn't stretch so if you know exactly what that is please let me know in the comments uh but otherwise let's uh let me show you what I got I have this chunk of aluminum heat sink left over from an old battery that I took apart and I'm going to use this little thermally conductive mat that's on it so I'll take this plastic isolator and use it as a guide and just put it on here I don't know exactly what size that is but I hope it'll be the correct size now I can just peel this off and I'm going to move this over to the other side thermally conductive mat okay so now the aluminum can go right here yeah so that'll work really well so now I need to band it this is the banding kit that I purchased on Amazon I'll leave an affiliate Link in the description below it comes with all the tools you need some clips the banding strap itself and I just thought it was a good value for everything I got the idea for this from watching one of lithium solar's YouTube videos he makes really excellent videos if you have not checked out his Channel please do so seems pretty straightforward there's a little instruction card that comes with it so I think I'm going to try this again and I had a thought maybe I'll put the tool here and have one of the legs still wrap around so hopefully I can put the metal crimp on this side this metal crimp it's not exactly sharp it is a kind of of a curve but I'd rather have this off to the side so let's give it another shot that was more difficult than I thought it was going to be it took about 12 separate tries before I really felt like I got the tension correct knowing how much to ratchet and how much tension to feel on the handle to how much tension would result here but at this point I feel like I've got the same tension as what was here originally and again it's just based on feel again this is a smaller distance so it's going to feel harder to get the same stretch out of it compared to the longer distance but we're not trying to put the cells under tension compressing them like in a vise or something what I'm trying to do here is just prevent them from expanding and I'm trying to prevent them equally on top and bottom in the past a lot of us have used threaded rod in fact that's I got my inspiration from my Chevy Volt the Chevy Volt had long threaded Rod through the whole length of it so I was duplicating that on subsequent builds but this is a nice clean it's a non-conductive material this pet I think it is and I think the overall thing now works pretty well in this arrangement so I'm happy with it but just recognize that you might have to spend a little bit more time getting the feel for it we have the main negative of the whole pack is right here what I had taken off originally was this it's a nut that's encapsulated in a little piece of plastic and that went in right into this location the original one had this plastic cutaway so I'm going to have to cut this piece of plastic for the wire way off to the side in order to get my clearance so that'll be the next thing to do to modify this little piece of plastic wire way thank you [Music] this is the wiring harness for the BMS that I'm going to use and the black wire here is the main negative so it has to come up to this post which is the main negative post of everything of the entire battery I should have soldered this on before bolting it together but I didn't realize that I needed to add a wire here see there's wires for all the other cells but I didn't realize that when I cut this off the voltage sense wire for this tab was actually on the cutoff side let me catch everybody up with where we are right now well this is a lithium battery and all lithium batteries should have a BMS or battery management system in this case I'm using this BMS it'll be the first time that I'm using this particular model from battery hookup it's a 300 amp continuous model and I did that because these cells can discharge 280 amps continuously as well as charge so they're pretty powerful cells so I wanted a powerful BMS to pair with them uh probably Overkill in my situation but it'll be fun to try it out now the main two blue wires here they're called B minus they're going to come up here to the negative post that I created but the BMS it needs to read the voltage of every single cell so it comes with a couple of wiring harnesses because it can accept so many cells in this case 16. we actually have two separate plugs with a sets of wires on each and we need to wire all of these so that they're reading the cell voltage of every single cell I've already connected a couple so now I'm going to bring in and show you how I'm reusing some of the existing wires so you can see how I'm connecting up the existing wires to the new wiring harness so that we can then connect it to the BMS now the reason why the BMS wants to see the voltage of every cell is because it can actually shut down the battery pack if a single cell goes over voltage or under voltage so that's one of the benefits of this now this particular BMS also has a balance function so if the cells were out of balance meaning not equal voltage to each other it can passively balance them passively balancing means that it can burn off some excess current through the resistors that are built in we have the main negative lead which I brought up here and is soldered directly to that little piece of copper it looks like a coal joint but it is stuck on there and it's not coming off so then the second lead which is White is coming off here and goes to the second cell so it ties into the blue wire which is already attached to the jumper bus bar here and I'm using these little uh I'm using these little heat shrink things they have some kind of cold melt solder on them they're just easy to work with when you're doing something like this remember these wires won't be carrying a lot of current at most if the resistor of the BMS is on this will carry a tenth of an amp or something like that so having a little cold solder joint like this is not a problem mostly it's just reading voltage all the time so I've already done these these three the black and two whites the next one is this white wire so I'm going to fish it through my fingers so I don't lose it and it's this one so what I like to do is trim off little pre-soldered end we strip that and now I'm looking at where that needs to go so I already did the black wire the white wire the purple next one is this pink wire some some type of little twist then I get that little bit of solder positioned right over the Twisted part and now we heat it all right so now I'll just carry on until I get all the wires on this side and all the wires coming down off this harness as well at this point I think I have finished wiring all of these BMS leads I have them taped off here so that we can test them before connecting them to the BMS now this particular BMS can go from something like seven cells up to 22 cells so it has an odd connection that you have to make over here I've got a bunch of wires here I've got six different wires all tied into one from the battery so this particular part can be very confusing so you gotta look at the wiring diagram battery hookup post the wiring diagram for this BMS and it's pretty clear if you just watch it all right so now we need to test this but I need to put the little Jumper in the back connecting the two sides so let's do that from our main negative which is over here to our main positive 52.71 Volts for the whole pack now we need to individually test each wire lead so this is the main negative wire of the entire pack it comes over here now the very first lead is a little bit nerve-wracking because these pins are so darn close together so you gotta really kind of angle it out and you can see it's a 3.2 volts that's for a single cell now I'm going to move the red probe over but as we're going across let's just say all right we're at the end of this plug and we're at 42. jump over here 46 46 this is where they're all grouped together all the way down the line the wires are grouped together until we get to the end now we got 49 and then the last two 52 and 52 the last two positives are also grouped together but again this is in the wiring diagram always follow the wiring diagram don't just watch my video on it but it's really important to check all of these we went up by 3.2 each time we didn't have any crossed wires it wasn't like we were going from six volts all all of a sudden to 50 volts you know we didn't cross them somewhere so always check these before connecting them to the BMS we're done with the wiring at least temporarily enough so that we can perform our first test so we've got our BMS here wired up to the negative post and what I've done is run it down to my meter and off of the inverter which is right here I've also got this extra set of wires going to this charger so we're currently charging we should be done charging very soon we've got 53.4 volts on this app on the phone is reading the Bluetooth off of the BMS so this battery management system has a Bluetooth built in which is going to the app which I downloaded on the phone you can find the app to download on battery hookups website if you scroll down on the page where you buy this it has the downloadable version for both Android and Apple if I scroll up here you can see the all 16 cells and we're all very close in voltage to one another everything's looking good it shouldn't take too long before we hit a high voltage and I'll try to catch that when it does [Music] so the BMS beeped and it disconnected charging I heard it click I heard the contactor clicked I changed the parameters so that anything over 3.5 volts it can balance it had it at 3.3 which was a little bit too low for me so we're off just a little bit so let's go check that is cell number five and see if it's reading correctly it says cell number five should be 3.6 which should be this one I think yep and that's reading correctly 3.672 3.671 oh it's dropping as you can see it's dropping here as well and then if I move it back 3.50 and over here 3.50 so that tells me that the BMS is reading the voltages correctly so we need to do a top balance on these cells over the last few days I've been letting this BMS top balance all the cells so all the cells look great I discharged it a little bit and then recharged it so we're at a hundred percent and we're ready for our first capacity test I love doing capacity tests now since these cells are so large I'm going to have to put a larger load on it and in doing that I redid my whole setup down here so we've got the victron shunt connected with Bluetooth to an app on this cell phone I've already zeroed out all the history so we're going to be able to measure how many kilowatt hours go through the victron shunt I've got a 125 amp circuit breaker everything's currently off and I've ran this with some two watt wire going into my grow watt inverter that I pulled off from the wall just off camera I've got a 240 volt space heater I forget exactly what it is something like 4 500 watts or somewhere around there now I'll bring the camera in closer when we actually go to start it but what you'll see me do first is use this little resistor to pre-charge the capacitors inside the inverter then I will close the circuit breaker if I was to just close the circuit breakers right now you'd have a big surge a big inrush of current into the capacitors because these capacitors are dead right now and capacitors are are built inside of all inverters now that might damage the capacitors they might survive but they might get damaged so I don't want to risk it so I'll just use this little resistor we'll pre-charge them and then close the circuit we'll turn on the space heater and then we'll check it on the app and make sure that it's running well and then let it go we're going to attach this to one side it doesn't really matter which side of the circuit breaker I'm attaching it to and I'll also show you what we've got at the inverter see that I had this on a little bit earlier and the capacitors are still dissipating a little bit so it looks like we have uh 400 millivolts right now so hopefully everybody can still see that we'll take the other end over here so see that's all it is and I'm going to touch this on the other side of the circuit breaker see we have full Voltage now that's all it took just a second and now we close the breaker and we have full voltage and so that was gentler on the capacitors take that away and right now we've got a hundred percent we'll just turn on the inverter there we go you can see some watts are going in as the inverter is kicking on you'll hear the relays click inside right now it's just warming up there we go did you pick up on that click and we've got 240 volts coming out of the inverter so right now the inverter is drawing 80 watts to be on and it's coming out of there going to a plug and then this shop heater so if I kick on the shop heater [Music] you'll see this just went up to oh over 5000 Watts after just two minutes you can see that the wattage draw has dropped and we're down to 89 percent for that heater and 4 900 watts or so being drawn from the battery that's because once the heating element inside this shop heater warmed up it actually increased its resistance so it drew less current this capacity test is running excellent these cells are 280 amp hours or 896 Watt hours per cell it's a pack of 14.3 kilowatt hours and so this is the range that we are working in we're almost done the Pack's about to shut off let's look at our history 14.2 kilowatt hours are we going to go up to 14.3 we've got 279 oh man we're almost there oh it just shut off and you see how the voltage just jumped up oh and it shut off makes me wonder if I had a little bit lighter load instead of a five kilowatt load could it have gotten that last point but final numbers 14.2 and 279 amp hours so we almost got there this was the very first capacity test I'm gonna charge this up we'll run another capacity test tomorrow and see if we get any better results so I changed out the load last time I used this space heater but it was a bit fast this time I'm actually going to run it into this charge verter there we go and this will let me dial in exactly how much load to put on it so I'm looking for about 2.8 kilowatts measured on the shunt that will get me right at about a 0.2 C rate we are just minutes away from the second capacity test being done in this case I've been using the chargeverter charging up a second battery Bank and the grow watt inverter here this is reading 43 volts I have it set to stop at 40 volts we're almost there we're still doing great five hour discharge there's been two times during the course of this test that I have adjusted the amperage rating on the eg4 just dropping it one amp at a time just to keep it right at the 0.2 C rate if we look at our history 279 oh and we hit 14.3 last time we only hit 14.2 and there's 280. so we did it our second round all right that's awesome so we did hit the mark on the second test and that's not abnormal for the first test to not get all the way up there remember these uh cells had been sitting in storage for the last couple of years and this was the first time waking them up we're almost there there we go you hear it it's about to do it there we go it just shut off drop that oh and I'm hearing that one beep all right that was great it's a 280 amp hours oh and this says 14.4 so we did quite a bit better we are about to start capacity test number three on this battery we've just turned on our inverter and over here we've zeroed out the shunt thank you and now let's go uh turn on our load we're gonna go back to this heater right now we're drawing 5100 Watts from the battery and as that heater warms up it's actually going to drop a little bit about three and a half hours into the test we're doing great 40.4 this is gonna die it's gonna die soon oh we're doing awesome this is great and it's about to shut off there did you hear it click it just shut off let's look at our history 282 amp hours and 14.4 kilowatt hours we just wrapped up three capacity tests in a row the first capacity test was just a little bit shy of the rating of these cells but that's also the first time trying to cycle these cells after been sitting for a couple of years now the second two capacity tests all met and exceeded the rating so I think we have a really good battery here all top balance uh good to go and I'm excited to get this hooked up and using it day to day in my powerwall there was one point where I had a glitch with the BMS this is my first time testing this contactor-based BMS and I had one glitch and I didn't catch it on camera I tried duplicating it for the camera but couldn't and basically the battery was full the contactor was closed I turned off the charger and turned on the inverter to start discharging and the contactor went click click real quick so it turned off and back on again really quickly but we weren't in a fault condition no over voltage so I wasn't sure why it did that and I wish I could duplicate it and catch it on camera again but I I can't or I tried and I couldn't catch it I'll continue using this in my setup to see if I see anything else like that happen I'll say probably restrict my recommendation on this BMS to just things like golf carts EVS instead of powerwall applications but I'll keep everybody informed if something happens in the future so moving on with this setup now that we know we've got a good battery I need to securely Mount this BMS so it's not going to go anywhere I need to secure the wires do a little bit of wire management uh I want to add a fuse now the BMS came with this fuse but all it says is 400 amps on it it doesn't say anything else no brand name can't look up any specs on it so I'm not going to use this particular one instead battery hookup cells fuses that are name brand fuses really high quality sometimes these can cost over 100 bucks sometimes a couple hundred dollars each if you buy them retail and battery hookup sells them for a couple of dollars when they take them out of a large module so I'm going to use one of these probably this one in this setup [Music] thank you foreign slid the battery into this old server rack cabinet by notching the rail in the rear to make room the front is still a little bit too tight this wasn't made for a server rack but it's so close that I think it'll work really well fitting in here now here's the front panel and I need to cut 5 8 of an inch off both sides in order to make this fit now I'm not going to be reusing these connectors I don't have this type and so there's really not a a strong need to reuse this front panel I could just recycle it but I like the disconnect right here so that's really the only reason I'm going to try to make this fit here's the original front panel and I trimmed it down on both sides and drilled a couple of new holes so it's going to fit into the server rack now here are the original negative and positive posts which I took out because these are a unique fitting and I just want to use something that's more generic so I bought these I've used these in the past on a couple other batteries they work well they're relatively inexpensive on Amazon but it's an insulated bushing there's a ring to secure it in place and there's this long piece of copper that goes all the way through so it can handle several hundred amps and it's got a 3 8 inch stud going all the way through so nice solid connection it'll insulate to the steel plate so what I want to do is drill out this opening a little bit larger so that this negative pose can fit in here I'm going to add this fuse so it's going to go right here so I'm going to drill out at this location that way I can secure the fuse holder and then I'm going to drill a new hole over on this side for the positive post so the positive post can go right here [Music] foreign [Music] so the BMS is attached with a couple of little standoffs now we'll bring these blue wires up to the negative post and I can attach my BMS leads all right we should have no voltage right now so let's double check that yep so we got no voltage that's so cool how that cams down and now we should have voltage if the BMS is working and we do 53.3 volts building this battery Bank was actually a lot of fun I'm really happy with the way that this battery turned out and getting it into the server cabinet but it did take a lot longer than I expected as most of my projects do so let's run through the numbers and find out was it worth it and would I do it again who might this be a good idea for how long did this take well it took me about two weeks working two or three hours a day on it to get to this point with one of the battery modules in the server cabinet remember a lot of that time was spent filming moving the lighting and the camera around uh also I had to figure out how to do it because I didn't have a plan going in I made it up as I went so I assumed that this second battery is going to take me a lot less time so between the two we're gonna wind up having about 28.8 kilowatt hours in capacity and probably 40 hours total in the project so for five thousand dollars and about 40 hours of working time we'll wind up with about 28.8 kilowatt hours I think that math was 173 dollars per kilowatt hour that's pretty good these server rack cabinets behind me like this one which I got from signature solar that one is working really well but that's about 300 per kilowatt hour so this is less but to make it even better I talked with battery hookup I talked with the owner and he's going to give an extra discount for anybody who uses my discount code which is davidpaws at battery hookup and this will be a temporary discount code I think he said 30 days he'll honor it and we're going to drive this price down for this setup to about 150 dollars per kilowatt hour I think with that added discount that means we're going to be half the price of buying the pre-made server racks so is it worth spending about 40 hours of time in order to get here and I mean I personally think it is because I don't make five thousand dollars in a week so for me it was worth my time these are really high quality cells and they're not used cells they're they've been sitting around maybe two years so their New Old Stock but there's no Cycles on them so really good high quality uh battery by the time we're done with this setup now that math does not take into account that we still have four cells left over so I've got a really nice 12 volt battery still waiting for me and when I cut open this module I'll have an extra four cells so I could either make a really powerful 12 volt battery or a 24 volt battery or what I'll do is I'll probably take those cells and series connect them with some other different cells that I have in the garage and create a large 48 volt battery Bank on top of it if a friend of mine was to ask me hey is it worth buying these modules for their setup I'd say probably if you're in one of two situations first maybe you have a cabin or something like that where your loads are relatively small and the 14.4 kilowatt hour capacity is plenty for you for your 48 volt inverter system plus the extra four cells the extra 12 volt battery that you'll get out of this setup can be used for say 12 volt lighting in a cabin or maybe a 12 volt water pump something like that and that way you keep it glued in and the reason why I like that is because cutting those four cells out was probably one of the more dangerous things that I've done on this channel in a while it is definitely under the column of don't try this at Home Folks so if you can keep those four cells in the tray and just electrically cut the bus bar and have two separate batteries still in the same tray that's the way to go now the other scenario that I really like for this is if you buy two crates now each crate comes with two modules so you'll have four modules total so if you can swing that from a cost upfront perspective which is something around nine thousand dollars then you would wind up with four of these so if it were me I'd probably buy some heavy duty shelves more like the pallet rackings type shelves electrically I would disconnect the four cells but wire them one shelf to the next shelf so I'd wind up with five batteries total five 48 volt 16s batteries now at that point with five batteries I would probably go with the uh smaller less expensive bms's from battery hookup these are 100 amps each and that means that with five batteries you'd have 500 amp capacity now that 500 amp capacity is plenty of amperage for uh most of us going off grid and our our home inverter systems so that's uh kind of the two situations now if you're in the situation where you got to kind of cut the cells out or remove the cells in some way well that adds to the time the difficulty and adds to the risk the danger this was not something that you want to be tackling uh I I like testing my limits and seeing if I can do it but it's not something that you'd want to do if you can help it let's run through the math real quick on the situation where you buy two crates with four modules so you'd wind up making five batteries in the end so you'd need five bms's and it would wind up being something about nine thousand two hundred dollars from battery hookup before the discount or shipping all five batteries together would give you almost 72 kilowatt hours of capacity which is fantastic that's more capacity than two of these racks and and then after the discount code and buying some of the accessory items like the terminals you'd wind up somewhere around 120 dollars per kilowatt hour total all said and done after shipping and after the discount code now personally I think that's phenomenal given that these are not used EV cells these are brand new cells with no Cycles on them but they are about two years old since the data manufacturer so if you have the funds to be able to do a situation like that right up front I think that's a fantastic way to go so in the future I'm going to be adding some angle iron rails into this server cabinet I'll be converting the second module put it in here then I'll parallel these together with some little bus bars inside the server rack and then run four out wire out to my central bus bars which are up on the wall for the inverter so I'm going to be paralleling this server cabinet along with the cabinet behind me which I have the batteries from signature solar so all of those can parallel together because they're all 16s lithium iron phosphate they also share the same voltage curve so there are a few nuances when you start paralleling a different amp hour capacity cells different internal resistance and we can get into that if there's enough interest in the future but thank you everybody so much for watching I hope everybody enjoyed the video and if you do please consider subscribing and hit that like button share the video and at this point I'm going to start working on the second battery module and get some iron rails in here to slide the next one in on top of it

Channel: DavidPoz

Views: 1,127,940

Keywords: battery hookup, battery, lithium, powerwall, backup, energy, emergency, solar, inverter, lifepo4, catl, eve, eev, cells, 3.2v, 16s, 48v, 51.2v, home, build, diy, save, money, cheap, 280ah, prismatic

Id: D2eXgiakD8U

Length: 54min 20sec (3260 seconds)

Published: Fri Jul 28 2023