Build your own solar battery and save thousands $$$

[@computerz009]

"If you can't explain it simply, you don't understand it well enough." Will I ever make a DIY battery? probably not, but your teaching on this subject is phenomenal. The way you can so easily communicate what is going on is incredible and had me watching the whole video. Great work sir

[@DavidPozEnergy]

Thank you for the kind comment.

[@dethmaul]

YES i noticed that a LONG time ago!! I haven't seen someone put my brain into words yet out in the wild lol. If you thoroughly understand it, you can find any number of different paths to dumb it down.

[@widnyj5561]

Oh man, 72kwh sounds really awesome, that's the realm of solar-only winter survival, pretty nice.

[@PsRohrbaugh]

Or air conditioning a McMansion on southern nights 😢

[@kusnezoff8705]

Now you're talking my language. It's about time you made a real diy battery pack.

[@ReizungV]

quite weak winters you have there then, unless you are using gas/wood for heating. I regularly consume over 70kwhs per day on the winters, I am using geothermal heatpump. The most consumed in a single day was 140kwh, but that was with some heat fans on in the garage and a 15kwh charge of my car.

[@tobiasobermayr501]

in a well insulated house you can go about 4-5 days on that yeah.

[@ifyoudisagreeyouarewrong]

@@ReizungV you wasting electricity isn't the flex you think it is

[@thomasharrison899]

"Video killed the radio star", and "server rack batteries killed the DIY battery". There will always be a few folks that still want to do it themselves for cheap :) Great job...

[@DavidPozEnergy]

Good analogy.

[@PsRohrbaugh]

I have had DIY lithium in my Sprinter van for 4 years and have been very happy. But now I'm doing a home setup, and want my BMS to communicate with my inverter. This is plug and play with server batteries and something like a sol ark. That's actually why I'm watching this video - trying to see comms options for DIY batteries. I need something that can work reliably with no intervention. Still making up my mind.

[@JasperJanssen]

Yeah, if these modules came as 16S instead of 20S, maybe. But this is a lot of work for minor cost savings. (And I suspect the supply of these things at the current price is hardly infinite.)

[@PersonalStash420]

@@JasperJanssen Battery Hookup has a 16s for sale right now. 16s, 51.2v, 240 ah, and 12.3 kWh for $1,200 plus shipping which is $300 to Texas.

[@breckfreeride]

Vertical killed server racks!

[@C4rb0neum]

I’m a software engineer and formally a mechanical engineer and I’m super impressed. The way risks are mitigated and everything is handled shows an insane amount of skills. I love it. Really nice to see

[@DavidPozEnergy]

Thank you.

[@ddecker3800]

Where to begin? 1. Super Nerdy yet very engaging. 8.0 2. Production quality is excellent for this type of video. 9.5 3. VERY informative. 10.0 4. Can be used as step-by-step instructions. 10.0 5. Helped me decide to just spend the money and buy a Powerwall from Tesla. (But that's me). You sir have a new sub.

[@DavidPozEnergy]

Thanks. I'll take that score.

[@user-zu1ix3yq2w]

How much is the powerwall per kWh? These were $150 per kwh

[@louisevad6091]

The problem our society has going forward is we don’t have enough people like you that have the knowledge or skills to do this

[@jaredlarson2810]

It’s not as much knowledge as courage, curiosity and very little fear of failure to acquire the knowledge.

[@lexpox329]

@@jaredlarson2810 expendable income is also an issue for many. You can't spend money trying things that might fail if every dollar is needed for something else. Yes I know most people also don't manage their money well at all but still I just in the last year have had any extra money to buy things like tools so I can even attempt to make things myself.

[@michaellarosa384]

Bought a crate plus an additional 8 cells for my solark 15k back in May, used the 300amp bms from battery hookup. Adjusted the settings in the BMS and solark. They have been running flawlessly everyday for almost a month no issues. The BMS will time out if the batteries sit for more than a day without any charge or discharge, but I load shed everyday so doesn't matter for me. Cells were top balanced and discharge and charge within 0.010 of eachother without an active balancer. $6.5k all in for 45kwh at 8 to 10k cycles what a deal.

[@jl9678]

Does it accurately measure charge/discharge compared to say a victron shunt?

[@michaellarosa384]

The BMS is a little off only one of the three banks is close, the solark does the SOC well and matches the amps in vs out even when I just top balanced again after 3 weeks

[@GenXMade]

Would u be willing to share your BMS settings? I have a 10.2 POWMr with these bat packs. My BMS is open/closing the contacter non stop. Cannot figure out why. Any insight into how you programmed your BMS parameters would be awesome.

[@michaelvanzyl8749]

Where do you buy these batteries

[@bcceo1]

Using a bmw i3 battery ( from bmw cold storage) I went 14kwh ( usable) with my second battery at 4.1v nominal on a 64 volt system I run the victron and bms on 60.2 volts for solar, and the generator runs to 58.6 on backup. Year 3 now on a sungold 18kw inverter switched to a 12kw inverter. Total cost of the bmw battery was 2800 with 00 wire for all the leads. Love it saving for 2 more. Battery never heats up because of the monster heat sinks built in. Tyty David for setting me off on my adventure. You Chevy volt battery inspired me!

[@RJ-cc1fz]

These are the type of videos I like from Poz. Was missing them. Well explained easy for most to build their own DIY pack. Even easier if the new CATL cells are purchased unassembled. They can be had for the same money.

[@user-rs8zg8ey2b]

singles showed sold out just now

[@dandriscoll692]

@@user-rs8zg8ey2b where does one commonly by the CATL cells?

[@espen2729]

Hell of a lot better than the cost of a Powerwall!!

[@jordankelley3414]

David, thank you for this video specifically. I just finished a DIY 14.5kw system on my house. I wanted batteries next. I was going to do a 6pack of EG4's for roughly 8500$ I was budgeting for it for next year....then this video came along. I watched and stared at that listing on battery hookup for half a day, entered your discount code and purchased 4 of these modules. The discount code was good for 10%, which was huge considering the price. Basically I got free shipping on 1400lbs of batteries. I just recently finished building 2 heavy duty carts for the 4 packs. So per your comment in the video, I am leaving the batteries in place, and wiring up 5x 48v modules to my Sol Ark. Like you said, a little bit of work saved thousands. It's twice the storage for the same price as the 6pack of EG4's.

[@DavidPozEnergy]

Sounds awesome. Thanks for sharing.

[@MikeG-js1jt]

if you got "Free Shipping" that just shows how much we are being ripped by the Chinese.......

[@stecder2470]

then instead of paying 9k , how much you ended up paying?

[@nickfirst7249]

​@@MikeG-js1jt do the product domestically then maybe?

[@PersonalStash420]

@@MikeG-js1jt Battery Hookup is a California based company.

[@UmpTSquat]

David, I don't understand why you don't have more subscribers. You are one of the top 5 battery DIYers on KZbin. I have learned a helluva lot about building batteries from watching your videos. I'm not building them at the scale that you are, but I am building them nonetheless and enjoying the process.

[@DavidPozEnergy]

Glad to hear the videos are helping you out.

[@solarcabin]

20+ years off grid with solar, wind and batteries and I would NEVER recommend people try to build their own batteries. That requires a high level of electrical engineering knowledge and if the soldering is bad you could end up with a massive house fire risking lives. Commercial LIFEPO4 batts have a BMS matched specifically for those cells and a low and high temp sensor to prevent charging issues and fires. When you calculate all the engineering and safety measure involved in a commercial battery that has a warranty you are not saving money and could be taking huge risks!

[@hansdenotter7376]

⁠@@solarcabindo you sell batteries by any chance??

[@CLRH2O]

@@hansdenotter7376 HA - Nailed it!

[@kameljoe21]

@@solarcabin you must be one of those people who want people to buy their stuff. Take a hike. People have been building stuff longer than you have been alive. This stuff is simple to build and do.

[@peterghali3947]

The timing of this video is perfect! I just purchased 50kwh of these for an EV. Thanks David!

[@easypowerwall]

Have 4x 16S too, works like a charm. Have fun.

[@restfulplace3273]

Now I’m curious what your ev project is. Please do tell

[@AnthonyRBlacker]

Also, you've earned my subscription. You are speaking honestly, clearly learning and teaching at the same time and you're actually being very helpful in the information you've created here. Thank you for taking the time to record and share this, I can't wait to get closer to electrical freedom, it has always been a dream of mine.

[@DavidPozEnergy]

Your welcome. Thanks for watching.

[@nonlocalitykat]

Great video! I bought 8 of the two-for packs of these 280 Ah CATL cells. Way better value than the $130 for each 100Ah I was paying. Glad one of the makers made a video using these cells. Keep up the great work! We're learning a lot from you.

[@local378]

I saw those how were you planning on connecting them, just drilling and adding a small bus bar?

[@martiruda]

where from???? I want to import to NZ

[@dcsco]

The most important questions are what was the cost of those CATL modules, and where were they obtained from?

[@monkeytrumpet7701]

I recognise these modules, they are used in industrial grid connected battery storage sites. There would be multiple containers with banks of these modules. I always wondered what cells were in them!

[@christopherleubner6633]

That and large UPS systems for servers and cell site transmitters. Replaced a 60v string of lead acid batteries. Those were heavy beasts... 2V and like 60 pounds a pop. 😮

[@antronx7]

These are nice modules for sure! I would buy 4 of them to connect in series for 260V dc and run 240v heating loads like stove, tankless water heater, clothes dryer direct on DC via solid state relays.

[@DavidPozEnergy]

That would be pretty awesome. If you do that, please send me a link. I'd love to see it.

[@clarke6436]

Would love to see the wiring diagram for that set and all the parts.

[@paulsanders4929]

Just building the same using scrapped BMW I3 packs. Pre-charge is to protect the contactors from welding not the capacitors. I really admire the detail and time you have spent making this video, well done.

[@jeffreykopf1589]

Would love to separate the 12v (4s) and 48v (16s) sections but leave them secured in place. Can’t help but think the 12v 280AH side would be great for a couple 12v heat mats so the entire thing can be used below freezing! Lots of good uses for this!!

[@DavidPozEnergy]

For sure, leaving it glued in place e makes a lot of sense.

[@kmschwem]

If you’re going for 4 shelves you could just run a second set of lugs and make the series connections with cables. Lots less work than cutting them out.

[@HaloWolf102]

Very descriptive with your instructions. Your teaching abilities should be exposed to most teachers in High School. I had absolutely no issues following everything you presented. All was coming in clear as pristine glass. Kudos David.

[@DavidPozEnergy]

Glad it was helpful!

[@mikybinns9343]

Awesome video as usual 👍 You have great patience and clear explanations😇 I've spent the last year buying various cells from different mainly chinese sources. I presently have 120, 200, and 280 x 2 ah packs all in parallel and 2 more in testing. They all work fine. I've tried various BMSs Jk 2amp active balancing is the way to go or JBD with an extra 5a active balancing board added . Definitely not Daly absolutely crap at balancing. Despite spending weeks parallel top balancing; passive balancing is no good with different capacities unless you reduce the maximum charge voltages to suit the weaker cells , which reduces your overall capacity. Its been a vertical learning curve. You seem to have more and cheaper options for solar materials than we do in the UK.

[@pavelsimon1076]

I watch it whole, without skipping. Excelent job. I am not educated in electronics and its really hard to me orient in much more simplier things, but this is crystal clear. I dont know how other countries but in our, we are limited to connect anything more then 50kW without license, used to be last year max 10kW.

[@rocktech7144]

Yes dave lets get into paralleling different capacity lithium batteries in a main system. Alot of people I know are looking to upgrade capacities.

[@exponentmantissa5598]

That is not a good idea to mix different capacity batteries in parallel. What happens is one bank some charge up first and the others will be left undercharged, then there are issues with a battery discharging into a dissimilar battery.

[@mb-3faze]

34:00 you can switch the breaker on while the pre-charge resistor is still connected - that's even gentler on the capacitors in the inverter. In fact, in an EV pack, for example, the pre-charge resistor is always present but switched in and out using another switch (aka a relay) while the main contactor (your breaker) is operated..

[@aday1637]

Better choice for banding is Harbor Freight's banding clamp witch is 15 foot in length and would easily fit around the cells. It uses a ratchet to tighten it. It comes with 4 corner pieces to provide protection at the corners. It is $6.99 plus tax and shipping. That's what I used on my lfp prismatic cells. I used two pieces of 2x6 at the ends slightly longer than the cell width. My cells look identical you those you purchase in that pack. EVE and CATL sell the cells individually with M6 threaded studs. for low price. I bought the 230 a/h one's for $100 each including shipping.

[@DavidPozEnergy]

That's a good idea. Thanks.

[@rob2950]

Where did you get those cells… sounds like a deal. 😊

[@sinamos3945]

Where did you buy?

[@passerau]

First of all I just want to say thank you for all these details and a very nice and informative video. This video was posted 9 months ago and was most likely made at least 10 months ago. Currently on the market you can buy a Eg4 48V 280Ah | 14.3kWh battery for $3,400 before any rebate or discount. If you buy more than 1 they will definitely give you a bigger discount with a 10 years warranty. You will still save close to $1800 with the acquisition of 2 Eg4s, but you definitely lose that in time, labor, and logistics, not to mention a 10-year warranty. Ty🙏

[@apoco_lips9957]

you can buy a similar battery pack that is 27kwh and needs re configuring $2400, plus about 400 shipping, 3bms if you split the pack into 3 48v 9.2kwh packs (about $400 if you buy 3x 300 amp bms). So nearly double the eg4 capacity for around $3200, not a bad time to be buying batteries either way really, built with warranty or diy

[@jasontram7775]

Here’s a tip for measuring the voltage of the first cell via the BMS JST connector and the pin for the first cell is uncomfortable close to the common/ground pin: Measure the voltage (potential) for a series of cells, ie. 16V from 4 cells when measuring from Pin 1 (Common) to Pin 5 (4th cell) and then subtract from that the voltage (potential) you measure between Pin 2 (2nd cell) to Pin 5 and that will give you the voltage (potential) between Pins 1&2.

[@jacquesdutron9954]

Thx a lot DTG, this was awesome. It always amazes me the length at which you go to test very complicated things. You're one of the kind. Thx

[@DavidPozEnergy]

Your welcome. I'm glad you appreciate the extra time it takes to make a good review.

[@theosky7162]

Great Inspiration, particularly liked the realization that 4x 20S = 5x 16S hack to standard 48v system. Pre-fab structure is a plus. My only real concern is what happens when a single cell needs replaced. Your experience of disassembly does not seem easy for long term maintenance. Thanks for the effort and sharing.

[@onlylettersatozornum]

I think that concern is part of the reason for even DIY to start from a very robust product, as David selected here from BatteryHookup, and I think both the original design and David's approach to keep it similar take failure somewhat into account. As long as the failure mode is just more severe degradation than other cells, that single cell worst case would only drop that 16S string voltage to 15/16th, that's still nearly 94% (95% for original design 20S). Even if over 6% capacity loss seems severe, the 5x parallel arrangement brings that down to just 1.25% capacity loss overall, as the other 4 strings would level out power for/into the degraded 5th string. Now if you're concerned with an Open-Circuit cell failure, which I assume would be extremely rare, and if you consider it too difficult to remove/replace a single cell, your repair might consist of disconnecting/bypassing that OC failed cell with the aforementioned same result of nearly 94% capacity still on that string and nearly 99% overall pack capacity. Assuming a static installation for off-grid rather than EV, you could even extend a cell outside the pack, if the original enclosure/geometry didn't leave room for spares.

[@MicroplaysMC]

AY I JUST BOUGHT ONE OF THESE PALLETS A WHILE AGO. I'm very glad I can see someone else tackle this type of project! Thanks for the video :)

[@defjamsgreen]

Wow ! Way totally off the change . 🤗🤙All I can say David . May the solar be with you .😉🔋🔋🔋🔋🔋

[@DavidPozEnergy]

Thanks.

[@USA-GreedyMenOfNoIntegrity]

I bought one JBD contactor based BMS. I ran into the same glitch as you ran into and more. All JK BMS’s from 18650 now. Finally no more Aliblabla to buy cells and BMS’s.

[@trevornelmes9331]

$170 per kWh is what I recently paid for 64 280Ah Eve Cells, four stackable DIY metal cases (no, not made by Seplos), Seplos BMS, active balancer, busbars, breakers, fuses, wiring, tower base trolley, including shipping and taxes. All brand new kit, I had to assemble it. I did make a few mods to improve the design, which took a couple of hours per case, but then the assembly was less than an hour per case.

[@gruetoo1]

Did same using Seplos case NeeeeeY Smart balancer, and cell directly from Eve. A bit more, but easier to repair if needed. I love the concept, but a bit too DIY bordering on designed by. In order to maximize the savings you gotta go for the 4 pack. But at 8k and no box no BMS I have to consider the 50ish dollar increase (per KW) to be small. I personally would do this if the price difference was at least 1,500. more. Also the server rack he is using is not cheap. So if you get some warehouse racks you can add another 500. Last note would be moving them into the racking. I don't have the lifting tables he uses. I guess I can get a cherry picker. All this to say the savings would be eating up quickly. Great Video David.

[@thefirstfootprint]

If not Seplos, who did you go with? .....and was everything from the same supplier?

[@KoiAquaponics]

Now this is what I want to know more of. Where do you get everything for $170kw assembled. These catl cells are amazing though. But buying everything else also adds more. Can you show me where you shopped?

[@abhishekkushwaha2455]

@@gruetoo1do you have link for eve battery shop? how did you bought them directly?

[@richardmarkham8369]

Trevor, who did you buy from? Fogstar?

[@tookymax]

I've been told that Lithium batteries last much longer if you charge them no more than 80% and discharge them no less than 20%. If that's true, then your 10 batteries are overcharged in the condition you bought them. 65.99/20 = 3.294 volts Is it possible to program the BMS, to only charge to 2.6352 or 80% of where they are now, assuming they are at 100%. That way you would enhance the batteries lifespan and retain the "Cooling Tunnel" that was designed by the engineers. Also, there must be a voltage regulator located somewhere within the system that keeps the output voltage at a stable 48 volts, regardless of the batteries charge level. Wow, you could save a lot of labor, just have to nix the 12 volt battery. Maybe an engineer can comment on this, Thanks for the great video Dave, keep up your great work.

[@DavidPozEnergy]

Yes, you can change the settings in the BMS. However, the BMS shouldn't be used to limit the charging Voltage day-to-day. Instead it's better to program your charge controller to a lower Voltage setting. For example, in my system I charge Bulk to 56.0V, but I could drop that to 55.0V or 54.0V if I wanted to be more conservative. (this is with 16s)

[@boatelectricaldiy]

Love your content David! I didn't see an anti oxidizing compound put on between the copper and aluminum. You will need to take that apart and put some on if you don't want these two dissimilar metals to corrode.

[@brainwater]

Unless that's nickel plated, not aluminum.

[@mlindholm]

⁠the terminals on those batteries are aluminum, with aluminum bus bars laser welded to the terminals.

[@shodanxx]

@@mlindholm Yes, you can see inside the cut that they are not copper at 14:19 i.imgur.com/9NYH3It.jpg Probably not solid nickel either. So, are standard lifepo cells normally using aluminium terminals ?

[@janosszabo98]

@@brainwater It didn't throw any sparks when he cut it, so it's not steel for sure, and the whole cross section silver colour. Also it bent easily, so aluminium is a pretty safe bet.

[@TinkerbatTech]

Nice video. I have one of those sitting out on the deck, ready for mods and installing as my main house power backup. (Currently 36V Li-ion, about 5KWH) Looking at another 4 cells from Battery hookup and setting up as a 24V 8S3P config. (House setup is rather low power, I can get couple days of essentials with my Li-ion setup so this'll be much better. I'm on grid, but in the redwoods where power tends to go away for days at a time. No solar, too many trees, so have to grid charge or generator if a really long outage...) I was very impressed with the build of these packs and the great cell voltages when received. _Might_ think about another pack, but still recovering from hauling the last one up 43 steps. Fun times. But it'll outlast me once it's in place, those cells are scary long lived.. Learned a lot from your video, gave me a couple of ideas on my setup and how to implement it. Wish i'd waited a bit longer to buy the batts, tho, missed the discount. The free freight deal, tho, cinched my jumping in as it's pricey to get 'em here to NorCal.. Looking forward to using these. Great video and what looks to be a great battery! Stay safe. Stu

[@darshanags]

Giving me ideas, Dave. My wallet isn't going to like this at all.

[@billykulim5202]

when the title of video come out, i though he was going to teach us making our own lipo4 battery, i was wrong,

[@KP-sg9fm]

​@@billykulim5202 wouldn't be surprised if that's the next video. Guess I should go buy a pickaxe.

[@simonlinser8286]

Wouldn't it be a thing you'd be buying anyways if you need it? It's not like you're buying a video game or something you shouldn't. And if you are getting energy you'll save money paying for it, if you don't have a battery you'll need one anyways, and if you do need one buy it sooner than later because the price isn't going down anytime soon. And build your own.

[@brofessormex]

That's my problem too😊

[@leukota]

On the contrary your wallet will love you if you go Solar. Assuming you are grid-tied, hybrid battery backup allows for on-peak power use (outside of heavy 240V loads). You sell back more to the grid during peak, whilst running house on battery, alleviating peak rates. If you don’t have solar idk what to tell you, you either don’t fully understand the financial benefits, or you don’t qualify.

[@RS-lt2ue]

Takin notes for my project on my new adventure. But, I'm pivoting to a higher voltage, we will see. That quick disconnect is also very appealing for the system. That way each battery bank can individually disconnect.

[@sagelikea6130]

I've wanted move entirely to solar and battery with propane gen backup but cost has been the barrier. I've also never done anything like this before but I'm pretty good at working through things and think I can do this safely. It's tempting at this price.

[@suness_solar]

We simply believe that it’s worth exploring safe and cost-effective ways to store solar energy because providing our readers with options and autonomy is incredibly important to us! We can’t say for sure how much you’ll be saving for this project since the cost of building a DIY Powerwall depends on a lot of factors, such as material prices and the cost of your time.

[@whereserik]

"I love doing capacity tests" lol, so many things to like about Dave👍🏾

[@DavidPozEnergy]

Lol, I get excited over silly things, I guess.

[@whereserik]

@@DavidPozEnergy nah, Not silly. You love your work, and that's why we value your channel.

[@matthewtaylor3351]

Very insightful seeing this car battery tear down. Air vents between batteries & ripples in the battery connectors to allow movement

[@antronx7]

Don't cut that second pack! You should work out a deal with battery hookup to get you 3 more modules so you can wire them as 5 x 48V packs as you describe without more cutting. Then you will have 6 x 48V strings total + extra 12V battery. You could sell your EG4 rack to help pay for that.

[@DavidPozEnergy]

Good idea. Battery Hookup gave me a discount on these packs already. They are a small company and I don't want to take advantage of them.

[@vp3319]

Thanks David, I am now dreaming of such batteries, I have a WV EV three string (48V) 2014 and 1 string 2019. total capacity about 14Kwh. And only recently I reached the limit of 105A in charging (500A for me cosmos) because the inverter is not powerful (victron multi 5000VA). Now I am saving money for catl batteries (280AH class B, because class A is expensive..).Good luck in future projects (independence is expensive). 💪

[@BobHannent]

When you did the precharge, you would have been safer to attach the first clip to the inverter side. As it was you had a floating lead on your table unfused with full voltage/amps for longer than necessary.

[@DavidPozEnergy]

Good call, thanks.

[@BrianVattiat]

I keep lever nuts on hand to temporarily insulate cut wires instead off gooing the shop up with liquid electrical tape. Great content!

[@DavidPozEnergy]

Good idea.

[@martinmiller7623]

Your videos and skill sets have greatly grown great job sir.❤

[@paultarp9150]

Thank you for your description of voltage needs. I wasn't understanding at first why you weren't using them as-is, and adding resistance. Charging voltage is a good reason. I have a lot to learn, and will watch your videos closer. My solar system has micro-inverters, and may require rectifiers, and transformers to work with batteries, but Idaho is trying to change how they charge people with solar to make sure they pay more for grid-tied solutions, so I might have to do something soon. Thanks for teaching a bit. The site for sure doesn't have those batteries anymore.

[@DavidPozEnergy]

Your welcome. If you want to add battery backup to a micro-inverter system, then you need an inverter with a feature called "grid forming" and "AC Coupling". I'm using a Schneider XW PRO inverter that has this. I have some videos on that inverter.

[@AllAroundTube50]

I'd love a video on paralleling different types of 48V batteries! I thought it could only be done if the packs were identical?

[@DavidPozEnergy]

Thanks for letting me know. It helps me plan future videos.

[@PsRohrbaugh]

It's an advanced configuration, but it's absolutely possible. Your parallel banks will discharge at slightly different rates and you have to keep an eye on the charge states. The big problem is different battery chemistries in parallel - like lifepo4 and lead acid. That can be done in very specific circumstances (like a few minutes while switching between banks) but owing to the massive difference in charge states per volt, you can't leave it connected long term.

[@pigbag79]

Yes, please do a video about paralleling banks of LiFePo4's. I already have a closed circuit of LifePower4's - but always wondered if I could build my own battery, parallel it in without confusing the inverters in the closed system, or if one bank would spend most of its energy recharging an adjacent parallel bank...

[@johnwehunt4305]

Indeed, I purchased 2 48v 16S Paralleling BMS.

[@wideawaketotruth5301]

Thanks David. Always a pleasure to watch you complete a project.

[@glentaybow]

Loved the video David. Clear explanations. Keep up the good work.

[@tomwilliam5118]

Talk about the coolest DIY project I've seen so far on your Channel

[@DavidPozEnergy]

Thanks, I appreciate that.

[@zweriuskriegsman]

I like your video's. Would be very interesting to see how you could parallel batterypacks with same voltage (ofcourse) but different capacities. Especially for people who already have a battery pack, but want to extend it and can't get the same capacity cells anymore.

[@DavidPozEnergy]

Thanks for expressing interest. It helps me plan future videos.

[@ambersmith6517]

Yep that would be a good video!

[@dancampbell167]

I would be interested as well. Makes future planning much easier with the great information David gives.

[@chimpo131]

@@DavidPozEnergy if only these weren't laser welded together I'd bite. hate the idea of not having easy access to reconfigure them or have the ability of quickly replacing a bad cell.

[@user-rs8zg8ey2b]

@@chimpo131Hmmmm, laser welded? I did not see that in the video, what time?

[@NicInLvNv]

Great Video David. Informative for a future system and since the discount expired I will be more attentive. Thank you again…

[@johnwatts3339]

As usual, great video David. It's a pleasure watching your DIY projects. Thanks!

[@DavidPozEnergy]

Thanks for watching

[@jacquesdutron9954]

Hello DTG, you're just relentless in your awesomeness. Guess what, EG4 just came out with a new battery, you don't even need a server rack. Just put it against the wall, right underneath your systems. Good for off grid. 14.3kwh lifepo4. 300 lb., 280 Ah, 51.2V. 200 Ah charging, 200Ah discharging, they come with cables for parallel connections, only 2 batteries for maximum hook up. I hope you get a chance to this new battery and compare it with the AES from Discover.

[@jws3925]

David, this is another great video. Thanks for putting this out there for all us LifeP04 nuts. Certainly something to consider. I actually have a remote cabin just as talked about with 12v lights and small on demand water pump! Presently only have a small system with 385AH LifeP04 battery I built from raw cells. I do have a Samlex 1500 watt inverter that is only minimally used but if we were to go big and have a larger battery and inverter we would "find" more use for 120v AC. This Solar/LifeP04 stuff is addiction. It just makes one want to build more batteries and put up more panels! Where does it end???! Is there a LifeP04 rehab center in the US yet? Perhaps you and Andy could start one!!

[@DavidPozEnergy]

That's awesome you have a small cabin with 12V lights. Yes, the addiction is strong.

[@johnwehunt4305]

Thanks David. I got a nice discount on the 2 module purchase. Helped to not hurt so much!

[@davedownunder8057]

Well done David your content is a great help for newbies like myself to understand and see how to do set-up, cheers from Australia

[@htn1986]

I’m sooo tempted to grab a set of these module after watching this video. So much knowledge in this video and presented in a fun way. Thank you for sharing, David!

[@DavidPozEnergy]

Glad you enjoyed it. Thanks for watching.

[@SkypowerwithKarl]

That 16S wiring diagram is a new one to me. That 7 wire tie in at 14+ and two wires to 16+ is unique. They are all different, gotta pay attention for sure

[@GetFitEatRight]

That's amazing, you get 48v and 12v for legit anything else. I can think of a million uses for 12v. (Troller Motor, Sump Pump, Water pump for garden, OP Car Jumping Battery, RV battery)

[@notoshaapproved]

The thermal putty looks like the same thing they use for CPU's in PC's. In case you didn't know, the overkill solar app works with JBD BMS's as well. I prefer it over the regular one. Great video as usual!

[@billyboy969]

That's what I thought too. In computer class they teach to not forget the dope (paste)

[@MRX625.]

Thanks David. I got wiser about this BMS, Following you from now on. Have a great weekend. 😀

[@kirkoliver2878]

Very well done presentation David! It was detailed but not confusingly so. Thank you!

[@gardenerpete5232]

Fascinating videos! You describe what you do very well. I'm a retired electronics and mechanical engineer. I would like to make a few safety comments. Racks (what you are using) come in all sorts of weight capacity ratings. I saw that you mounted your first battery tray in a rack. What concerned me is the screws were about 1/3 in from the top and bottom. You should have a second set of screws 1/2 inch from the top and bottom of the front plate, a minimum 4 screws per front plate. The front plate screw holes (all screw holes) should be a slight friction fit so the screws can't slide across the plate allowing rack to lean. Racks are fairly stable front to back, but not side to side. If you can find the load rating of your rack, that would help you to know how to reinforce the rack for double over-weight. The other thing I noticed, there wasn't an air intake filter. You can make a cheap tin/steel intake that will take 1/4 of and air-conditioning filter. Have the filter piece a friction fit. If you don't, the battery will die of an overdose of dust. I envy you- battery & solar hadn't been invented when I was working in electronics. I was thinking about gardening and farming. I'm in my late 70's, have a vegetable garden and enjoy fruits and veggies almost year around! (Zone 7A, NY).

[@DavidPozEnergy]

Thank you for the comment. I'm not a computer person. I really don't know much about server racks/cabinets. I bought this used rack from my local recycler for $75. then I added a steel plate to the floor. The battery in this video is resting on the steel plate. Meaning, all the weight is straight down onto the base. The front panel is only holding up it's own weight (panel, terminals, and fuse). Not sure if that makes a difference to your suggestion or not. I plan to start a garden next year. It's something I need to learn about.

[@gregbenwell6173]

I clicked on this video thinking you were going to show a DIY way to "save thousands of dollars" on making your own batteries!! THEN I found the shortcut to the batteries you purchased and the price for what you bought was $2400 from the website you are linking too!! The point is, like a lot of other people, I don't have $2400 just laying around, and money in my life doesn't "grow on trees"!! Especially now that I am disabled!! In fact, batteries for me, will take me roughly a year of saving, to get my battery bank up and running, unless I bought a couple of batteries at a time.....and installed them into my system as I get them!!!

[@jamespayne8781]

Remodeling is always harder than new construction. This presentation definitely illustrates why dis assembly is just as critical as re assembly. Many people relegate demo to people of lesser skill and attention but sometimes that is a poor decision.

[@CaptBill69]

I like seeing this option for A quality LiFePO4 cells. Also wonder what specific EV these might fit into (as they seem like they were made for such).

[@JasperJanssen]

The module doesn’t look EV at all. It looks like stationary units. Possibly the grid scale storage systems. Edit: energy storage systems (grid scale) is indeed one of the things CATL is into.

[@michellelester243]

Wind farm was my first thought

[@jensschroder8214]

congratulations, the cells are already on a solid base, have cooling and are connected in series. All you need is a BMS and you're ready to go.

[@ThisRandomUsername]

Very interesting that they don't compress the cells much. Apparently the datasheets mention that the cells are guaranteed for a certain cycle life if they're under a certain amount of pressure.

[@michaellarosa384]

CATL made these they would know proper compression I would think. Everyone else probably does way more than necessary

[@chris_mk5supra]

you don't really need to compress them for solar energy storage, you don't push them hard at all, at least if your systeme is correctly sized, i NEVER compress my battery for solar storage, no probleme

[@Loveitdownunder]

A very clear and informative post. I found your channel by accident and it caught my interest as i DIYed a Caravan and 4WD with Solar (with 12v deep cycle batteries) for our round Australia trip.Subcribed as i want now to do my house..

[@DavidPozEnergy]

That trips sounds awesome.

[@billmiller4800]

I'm surprised you didn't try using a paint remover heat gun to heat the base plate and loosen the glue. I suspect it would have worked perfectly. Also another hint. If you're worried about sorting when testing those connectors with tightly spaced wires, use a piece of solid wire that fits in the connector hole and test one pin that way and the negative side go to the side like you did. This way the probes are separated with no chance of a short.

[@DavidPozEnergy]

I tried a few things, including a heat gun. I edited out my failed attempts to remove the glue. The video was sooooo long! Lol. This is about 1/2 inch thick epoxy.

[@billmiller4800]

@@DavidPozEnergy Oh WOW that's a lot of glue!! So a blowtorch wasn't a good idea either 😁

[@billmiller4800]

@@DavidPozEnergy I wonder then if a piece of piano wire might have worked. Still a great video!

[@I4got]

​@@billmiller4800 We use to take hot fence wire (depending on what length that we needed) and connect each end to battery cables to cut though like butter on plastic, styrofoam, glue, and many other things...

[@jasonhensley947]

Your content is some of the best sir- thank you for doing what you do. I personally would like to see the batteries together and hear your commentary.

[@AnthonyRBlacker]

The thermal pads between the batteries and also the ends is actually easy to acquire. They use pads 'thermal pads' on PC components, it's quite inexpensive, you can get sheets of it for not much money and it dissipates heat REALLY well. Might be worth looking into getting a bunch of it for the ends and between any battery packs you end up creating. It's good stuff. edit: I made this comment before you continued to find some and use it. Honestly it's just electronic thermal pads, they use it in GPU (graphics processor units) between the heat sink and the memory chips, well really under any heat sink that's not a CPU (we use liquid thermal paste for that) but yeah those pads are super easy to find you really just need to know the density and the depth of the pad, you can get it in rolls or as pre-cut pads or just big pieces. You probably already know this, this is a 10 day old video, but I don't really read comments and figured my 2c is just as well as the next guy's. Nice work here, I'm going to subscribe to you, I am super interested in learning all there is to know about renewable energy and getting away from buying government power. Thank you.

[@AleksStevanovSHELLTERRAArchPro]

Excellently articulated explantion, a true pleasure to learn from you. Thank you for sharing your talents.

[@the1maxb]

I didn't see you apply antioxidant paste between your fabricated copper terminal and the original aluminum busbar. This is essential to preventing corrosion and increasing resistance (and fire!) at this critical junction.

[@gruetoo1]

Conductive paste.

[@lasersbee]

Thanks for all the links David... FYI.. I just did a POrice check between a 20pc Module like your and 16 single cells shipped to me in Canada. Price per cell of the 20pc Module = $172 USD ea. Price per cell of a 16pc single cell (already taken apart) = $151 USD ea. I would be going with the single cells.

[@devonsaquariums2703]

I wonder how difficult it is to connect all of those together? All the bus bars are welded to the terminals. So you'll have to bend them up, or flatten them, then put your own bus bars to connect the welded pieces together I guess.

[@DavidPozEnergy]

There are different ways of connecting them. I've had my share of working with tabs in previous builds, so I'm comfortable with it. I'm sure I'll have a video on the process when I get there.

[@typxxilps]

2:57 shows dangerous damage on the edge of the cell with no more wrappping, no protection. And I wondered how that could have happened and if there is even more if you look closely enough. Best cells on the market based on specs, but for sure not the delivery state

[@DavidPozEnergy]

I just looked at the time stamp and I see what you are talking about. Then, I checked it in real life. It turns out that is some of the thermal paste that oozed out at the factory. I pealed some back and the blue wrap is still fully intact and there are no dents. Thanks for watching.

[@Swerly01]

I'd love to have one of these for my skoolie.

[@lunatik9696]

If you have large cells, one should consider an active balancer. It has made a big difference in my system. Did you ever consider using them as a 60V system? I wonder if the included BMS can be used. There are components that function at that level. I am waiting on a check to buy a pallet of these along with a pallet of panels. I am most likely going to use 2 - 48V units and combine the 8 extra as a 24V system. I am 24V right now and had a LOT of trouble getting 16 working cells for a 48V system. Bad used batteries sold as new grade A are everywhere.

[@DavidPozEnergy]

There are a lot of sellers on places like Alibaba selling Grade B (or worse) cells and calling them Grade A. I stayed away from it. At least with these cells you know you are getting high quality. There are some 60V systems, but if I was to keep to the original configuration, it would be for 120V systems (two in series). But I'm pretty happy with my current 48V system and don't want to change everything else just for one battery deal.

[@ABaumstumpf]

@@DavidPozEnergy "There are a lot of sellers on places like Alibaba selling Grade B (or worse) cells and calling them Grade A." and specially amazon nowadays.

[@ericklein5097]

I've been waiting for you to do a video on these modules. You were the first person I thought of when I saw these. So tempting to buy 2 modules with how cheap these CATL cells are. I'd like to see someone AC IR test them (and maybe load test a random cell) first

[@r3tr0nic]

Awesome video man, appreciate the share! I have used SLAs for a very long time. I have worked with Li-Ion, but only for small projects. Was absolutely not a fan of such a potential hazard (in the case of unexpecteds). The ideal of a 1000+ Li-Ion cell fire, no thanks! I've been looking to go Lifepo4, and came across these modules a couple weeks ago. Already an amazing deal, but your discount code set me going haha! Not to mention it was awesome seeing the teardown and what to expect inside. Unfortunately as much as I'd love to have the module in its entirety, LTL is expensive and they cannot even come to my location. Postage was less then half by just sticking to the removed cells. Budget ofc also always sticks it's finger at me, so for now I just ordered enough for a 16s build. Unsure on BMS, the 300A was out of stock. Went with 100A smart + the 500A relay for now. Unsettled, on the fence about an REC BMS, depends on how the 100A turns out. Same with balancing. I may also look into designing a custom BMS from scratch, maybe controlled by a Raspberry Pi. The concepts seem straight forward for how the cells are to be managed. I sent an email to see what they do with the module parts once they strip the cells out... I too really like that orange safety disconnect, and the overall build quality of those modules (wire tracks, fan cooling, etc). Would love to at least get the front panel, wire tracks, and aluminium plates between the cells. I still will have to think on how I will connect the cells and deal with busbars. Nickle plated copper is my first thought. Granted, it would be much less work just having the whole module and leaving as much in its original condition as you did. Thanks again for sharing!

[@alsemi-back-up579]

Good job Dave Do not read negative comments I have a 24 volt diy lfp system I built myself NO issues Still running my house NO issues New subscriber Keep up the Great work you are doing!!!!!!!!!

[@DavidPozEnergy]

Thank you. And congrats on your success with your system.

[@alsemi-back-up579]

ThanksDave

[@charlievickaryous9757]

Great content, so how would we go about leaving the battery as is ( as much as possible) and using a step down / appropriate bms to handle the voltage up and down….

[@peterwest323]

Had the same thought. Seems like it would be a lot less work.

[@billycairns9395]

Loved your video, I saved it and I can watch it again and again, thank you for doing that. Awesome for sure.😊

[@BlàckÐèàth]

Nice job, very interesting to watch. Love projects like this. Curious to see how you rack and connect the rest of the units. One question what did the original battery assembly weigh before you took it apart?

[@DavidPozEnergy]

I think the shipping weight was 700 ponds for the pallet, so maybe 330 ponds per module?

[@hartfordlabs7754]

I’m enjoying watching you use an assortment of “right tools for the job”. Nice work👍

[@LaDiables]

This seems like a lot of effort. You mentioned some equipment that would work with the native voltage? What were you referring to if you don't mind?

[@RoyCharles-x6o]

Awesome Dave I'm very much inspired . The way you explain is not confusing compared to some of the other KZbinrs

[@DylanMartinRacing]

How many of us are here that constantly watch stuff like this with the thought of “oh this would be perfect for_____” and full focus watch it to see how to do it yourself too. But deep down know you’ll never do it?

[@Pcg496]

nah, its me 😂 because what?? ya, money 😂

[@tonyp9179]

One day man, one day.

[@SolarTechFL]

I live off grid full time in fl Over the years i have added solar and batteries. Im up to 140KWH and 36kw of solar. I use 24-30000 kwhs a year

[@CSGATI]

He didn't make them just paid and rearranged them.

[@AndyShell]

? Yea thats how you make stuff. You take other stuff, take it apart then reassemble it a different way lol. Grab some tool and get at it man.

[@daviddemmers130]

You honestly thought a guy on youtube was going to chemically engineer some lithium batteries?

[@lectorhannibal9241]

That is so cool. I am looking into getting a solar system together but the cost of the batteries has really got my budget messed up. I think I will try this and see what battery hook up can do for me. I will not need that much power to start with. Thanks for the great video.

[@toxicity6629]

@@daviddemmers130bro we see people on KZbin playing with radiation and all sorts of manufacturing stuff on shorts shut up kid this isn't 1990 bro. Acting like we in the stone age

[@deeeyewhy5949]

@@daviddemmers130well he could have bought cells in bulk and the individual components more cheaper than this massive expensive battery he bought and disassembled

[@dougscott4008]

Always great info - and teaching for all solar information... just a couple of things: 1) I was wondering if banding the 12V that you cut out before removing would have helped the removal without cutting. 2) I was wondering if a moderate amount of heat would have helped release the glue before cutting out... just thinking out loud - of course not enough to damage the cells...3) I see you did not preserve the existing plug because you are going to your own BMS...Lastly, I love the idea of getting the two pallets to get 20-25% more power with another 48V :-)

[@DavidPozEnergy]

The glue on the bottom of the cells is a thick epoxy. I did attempt heating, and leverage, in an attempt to loosen it. The epoxy just wouldn't budge. I'll have to show the epoxy closer in my next video. The epoxy on the bottom is a totally different animal compared to the thermal paste between cells.

[@onegreenev]

You can use threaded rods to clamp and compress the cell pack a bit while you strap on the plastic straps. Then release the compression from the threaded rods allowing the plastic strap to hold the pack firmly but without excess compression. The compression remaining is spread out amongst the cells so no one cell is over compressed but the strapping is plenty secure. Those tools make it hard to get a good holding pressure without first compressing the cell pack a bit. My original attempts were with metal strapping. Plastic strapping is a bit more forgiving.

[@rschweichler]

Thank you for doing this! You are a great teacher and i enjoyed the info! That said i now have a great understanding of what’s involved in doing this! I will keep following your site and when i am ready for solar I will find someone as skilled as you to help me install a system like yours! Electricity is deadly and i do know my limitations! Keep up the good work you’re the best!

[@offgridwanabe]

Great video David. They would work great as is with my Sun 1000 grid tied inverters as they have a large voltage range then Just AC coupled to the main inverter, just need to bms and adjust the charge controller.

[@solarcabin]

20+ years off grid with solar, wind and batteries and I would NEVER recommend people try to build their own batteries. That requires a high level of electrical engineering knowledge and if the soldering is bad you could end up with a massive house fire risking lives. Commercial LIFEPO4 batts have a BMS matched specifically for those cells and a low and high temp sensor to prevent charging issues and fires. When you calculate all the engineering and safety measure involved in a commercial battery that has a warranty you are not saving money and could be taking huge risks!

[@UmpTSquat]

I used the 10% discount to buy 4 of the CATL 3.2v 280ah cells. I've been watching the price on those cells ever since they appeared on Battery Hookup. That 10% discount put me over the top, and those cells will cost me just under $500, including shipping. I canny wait for them to arrive.

[@DavidPozEnergy]

Sounds good, that will be a powerful 12V battery

[@jfssparky]

That puddy looks like what we put in between a computer processor and a cooling tower. It helps with heat