DIY 12-Volt 280Ah LiFePO4 Battery // Custom Box, Bus Bars and Assembly // Part 2

#VanLife #VanBuild #LiFePO4
In this video I will build an enclosure from glulam wooden boards, make my own copper bus bars and assemble my DIY 12-Volt LiFePO4 battery complete with BMS, cell balancer, shunt and temperature sensor.
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Build Your Own LiFePO4 Battery Pack for Cheap!
280Ah LiFePO4 Battery Cells - freelyroaming.com/lifepo4-cells/
Daly LiFePO4 4S 12V 120A BMS - freelyroaming.com/daly-bms/
5A-8A Active Cell Balancer - freelyroaming.com/active-cell...
Order link for US, UK and Most EU Buyers:
Here is the battery deal on AliExpress mentioned in this video.
freelyroaming.com/lifepo4-cells/
Watch the LiFePO4 build series:
Part 1 - All The Parts - • DIY 12-Volt 280Ah LiFe...
Part 2 - Assembly - • DIY 12-Volt 280Ah LiFe...
Part 3 - Capacity Test - • DIY 12-Volt 280Ah LiFe...
Part 4 - Installation and Programming
• DIY 12-Volt 280Ah LiFe...
Complete List of Items For This Build:
280Ah LiFePO4 Battery Cells - s.click.aliexpress.com/e/_AYk0Bh
Daly LiFePO4 4S 12V 120A BMS - s.click.aliexpress.com/e/_AKLJwW
5A-8A Active Cell Balancer - s.click.aliexpress.com/e/_AAlZrA
Digital Battery Capacity Checker - amzn.to/35uVIK6
Cell Voltage Sensing Leads- amzn.to/3krDc9G
Victron SmartShunt - amzn.to/32O70qX
Victron Smart Battery Sense - amzn.to/3pu31cQ
Watt Meter / Power Analyzer - amzn.to/2IBX8JG
Polyimide Film Adhesive Tape - amzn.to/2IEiTc3
Heavy Gauge Wires - amzn.to/3ppFbPz
Copper Tubing - amzn.to/38LFqhJ
Hydraulic Crimping Tool - amzn.to/2K51ZUl
Lumber for battery Enclosure - Local lumber yard
Not into DIY batteries but want to buy one? Here are some good options:
Battleborn 100 Ah LiFePO4 Battery - amzn.to/38xFUIi
ExpertPower 100 Ah LiFePO4 Battery - amzn.to/35dYLWN
SOK 100 Ah LiFePO4 Battery - amzn.to/3msXLEn
Because I needed mine to be shipped to Europe I couldn't buy from some of the cheaper listings for tax and customs reasons. It's more expensive than many other listings but I am happy with the quality and shipping experience.
Some of you have asked and the exact listing to the cells I bought is here:
www.aliexpress.com/item/40009...
Timestamps:
00:00 Introduction
02:22 Building The Battery Box
05:01 Installing Components
06:06 Making custom copper bus bars
08:30 Connecting LiFePO4 cells
10:07 Completed battery pack with enclosure
13:47 Conclusion
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[@ubermenschen3636]

Your video jumped from flattening copper tube for use as a jumper bar to a completed battery with all the wirings done. You are a bad boy!

[@donitmyself8935]

I would recommend replacing the Black shrink wrap on the positive cable with Red shrink wrap. You have 2 cables coming out of a very high Amp battery with no polarity difference markings. The risk of shorting out this battery by anybody that doesn't know to open case to see the Pos. Neg. marking would be high. Also if the short like that happened how much damage could be done before you smart controller could cut the power. Other then that looks like a very nice build and thank you for taking the time to show it off for everyone.

[@freelyroaming]

Yes indeed. I've indicates polarity with red and black electrical tape on all the ends since installing the battery.

[@posteroonie]

I've seen bus bars with an arch in them, to give flex when the temperature changes. Also, maybe it's a good idea to give those copper pipe segments a soak in some vinegar to take off the outer oxide layer, then rinse and dry before flattening, for maximum conduction with the battery terminals.

[@truckcampinglife]

I wish you had showed in more detail how you wired everything. I think that is the most important part.

[@Riverrockphotos]

Agreed.

[@jerrygundrum1]

I would not like the liability of doing an exact how too. I would read the manuals of your gear and wire according to their recommendations.

[@influencer_music]

@@jerrygundrum1 I came to KZbin to see a bunch of people do it to help prepare myself though.

[@MingoMoon]

Great work! Thank you for doing the video

[@freelyroaming]

Thank you for watching!

[@TheAndy19701970]

Thanks a lot for the video. I like it a lot. Keep on good working.

[@keylitho]

Some aluminum angle on the corners would really dress that thing up.. Great stuff..

[@VegasGuy89183]

I've used various sizes of old copper pipe hammered flat to make my own ring terminals and bus bars. I've never seen anyone else do it the same way. Now I can stop feeling so cheap. ;) GREAT series, BTW.

[@freelyroaming]

Haha that's right you use what you got!

[@Anchor2012]

I've done it too - its just smart. Dont feel cheap :)

[@marineg8397]

What is wrong with the bus bars sent with the batteries ?

[@freelyroaming]

Not wide enough to allow space between cells.

[@user-tj5nk7lb8l]

I guess for an RV use only drawing say 20C, heat wont be an issue, so your could strap all the cells tight together and use the original bus bars. I worried about vehicle shock vibration , put the box on springs for safety. I would install one of those purpose made battery quick disconnection links just in case. Lot of energy there to cause a fire if there is a fault.

[@richardservatius5405]

put a scrap of hose in the handles for lifting. put a heating pad along one side.

[@blessedwithchallenges9917]

Thanks for the link. I just bought 4 280ah batteries through your link!

[@freelyroaming]

Good luck with your build!

[@davefroman4700]

Keep them in the sweet spot between 30%-95% state of charge and they will last a LOT longer than their rated 4000 cycle life. Cycle life is calculated from max to minimum, the torture test of any battery.

[@freelyroaming]

Also this 4000 cycle life does not mean the battery becomes useless. It just reduces to 80% capacity.

[@edfrhes]

How long did it take for shipping to USA

[@blessedwithchallenges9917]

@@edfrhes a little over 2 months for me.

[@DaveRyan1974]

Unlimited thumbs up for making these very informational do-it-yourself power station videos!!!!

[@Sylvan_dB]

With all those screws it will probably be fine, but you could also use longer strings for the handles that could go down thru the bottom plate. That way lifting by the handles would lift from the bottom.

[@freelyroaming]

If I was carrying it that way regularly I would have probably done that and used thicker rope. It is also more comfortable to carry as these dig in to my hands a bit. But since it will be living mounted in the van, the ropes need to more or less stay out of the way rather than more in the way.

[@RoaldKoger]

Nice box. You could've gotten an enclosure from AliExpress. Yes, in Croatia too. My dad does it all the time. And if the adhesive tape on the active balancer comes loose, which will happen in a moving vehicle in hot weather, the unit's metal body may cause a short circuit.

[@freelyroaming]

Your dad lives in Croatia? Then he must understand the hassle we have to go thru of trying to order stuff here online.

[@freelyroaming]

Anyways. I needed this box to be a very specific dimension and did not want to deal with something that might not fit. And the active balancer is getting a metal bracket in addition to the VHB to hold it down. I've had VHB adhesion fail between plastic and wood in hot weather but never between aluminum and wood. In fact it adheres to aluminum so well that people use it to attach solar panels to the roofs of their RVs.

[@troyabrady00]

I knew that you weren't going to settle for nickel plated copper bus bars. Haha! You almost have me convinced I can do these type things myself. Almost.

[@freelyroaming]

Come on Troy! You got this!

[@Marcus-bb7kc]

I think the cells has to be tight together strongly because they are stretch and shrink while they are charging and discharging. So they original busbars makes sense. Great project. Thanks!

[@freelyroaming]

That is exactly the reason why I don't want them to be bound tightly together. It's not a good idea to force the batteries against each other if they expand and contract. You can tell that the manufacturer knows it because one of the holes on the bus bar is oval shaped which would allow some small movement. But it does not look enough especially since these cells have notoriously weak terminal posts. It's just a good idea to give them more space between the cells.

[@Swisslove24]

@@freelyroaming Yes this seems to be something to invent, enough space for expansion and still busbars that will not put to much force on the batteries, I think your solution will be just fine for now, maybe spacers or a frame on the edges of the blocks are good to have (3d printed), since the biggest expansion will be only in the middle area of the batteries, not sure if that is true though

[@mattwright2964]

@@freelyroaming I've seen people use thick tape between the cells which gives enough gap and allows the busbars to be connected.

[@jespero94]

Great video. Building a simular system to my van and this helps alot :) Do the batteriet get warm? Because there is no ventilation in your box but maybe not nessesary?

[@jeffallen3382]

Those LiFePo4 batteries are designed to be installed tightly together! You spacing them apart will allow them to expand and damage themselves!!

[@rlee23]

Nice Vid. Instead of running the four battery cell in series for 12v. Can you run two set in parallel to make two 6v and then run them in series to make 12v. So I can double the ah. I'm a novice at this . I like to know if this is possible. thanks

[@richpalmisano1740]

You do not want expansion and contraction. You need to compress the cells together to avoid this. It will prolong the life of the cells as well as keep tension off the terminal connections

[@peterwalton1502]

He taped all the cells together. Is that not correct?

[@freelyroaming]

I have a dedicated video that talks about compression. It will explain everything.

[@michaeldoherty2289]

@@peterwalton1502 No. Not good enough to compress the cells during charging and discharging. Should be heavy straps that can't stretch or even threaded rods.

[@fsmith7648]

Nice build, I like your channel there's a few issues I see but nothing major other than never ever use green/yellow cable for anything other than an earth connection unless you want to kill your friendly neighbourhood sparky that comes to work on your installation.

[@oneshot_onekill4618]

Dan do we have to have the shunt as well? Can i get away with the controller and BMS?

[@wanderingzythophile9083]

What thickness wood did you use for your enclosure? (Forgive me if this has been asked and answered already)

[@manooti]

I might go this route and do the same thing. What would you recommend for 48v 300ah? That’s the only thing holding me back…

[@timboone7449]

Just curious where you ordered the Eve cells and got air shipping?

[@deanharries4154]

What is the output difference between series and parallel...?? Does series give you a 24 volt system at 280 amps ...??

[@MariaGonzalez-ei1pv]

We're did you buy your buss bars? Great video...awsome idea with the copper piping

[@GEORGE-jf2vz]

For expansion between the battery terminals you might consider using copper braid cables.

[@trevorselch5574]

So at this stage, you can directly connect the positive and negative to your RV wires that connect to your converter? Does the converter need upgraded or that's what the BMS does?

[@Anchor2012]

BMS (the one he has here) just disconnects the battery if it detects a threat to any of the cells (over or under charge). Some components like certain MPPT charge controllers cannot tolerate not being disconnected connected from a battery while still taking power from the solar and can be destroyed that way - so you do have to check each components can work that way.

[@jackrussell4653]

I am installing a 200 amp Daly BMS on to the lifepo4 battery pack. I connected the balance leads and the B- negative wire. Without putting a load on it yet, I checked the voltage of the P- wire and the B- wire and they are supposed to be the same. However, the B- negative was correct at 13.20 volts, but the P- measure 9.60 volts. The P- should measure at 13.20 volts as well from what I understand from the instructions. Did you have that issue?

[@freelyroaming]

No mine is fine. Double check and make sure your balance wires are all connected to the proper terminals and the voltage readings are correct.

[@dillonkoch72]

That's a crimp tool for putting copper fittings on welding cable. You won't harm anything

[@Philips53]

Thanks for this video. I’ve also watched your video in compression vs not. You say it’s not likely that folks will charge or discharge at 1C, but if you do induction cooking or use a rooftop air conditioner on an RV, you very well could. On the other hand, if I put several packs like this in parallel, then would that charge or discharge be much lower and so expansion wouldn’t be likely? Example: if I have 3 x 280Ah = 840Ah, and run my a/c through a Victron Multi 3000, along with some other smaller loads, and I’m pulling a total of 2,400W from the bank, would this be right? 2,400W / 12V = 200A 840Ah / 200A = 4.2 1 / 4.3 = 0.238 so my draw would be 0.238C And charging at 100A would be 100 / 840 = 0.12C So with a larger battery bank like this I shouldn’t need to worry about compression, and may be better leaving air space (no compression and no foam, rather wooden spacers or nothing) between cells? Thanks for any help with this. Not committed to building my own since the price in these has come down so much, but trying to learn in case I do. Thanks.

[@georgesellers4936]

I was wondering if this battery setup would work on a boat for a trolling motor and another one for starting the outbound outboard motor I’m not a technical kind of person but I’m great at following directions and learning from people that are well versed in this technology and that is where you can help me please let me know how to do this. Thanks in advance! George Sellers

[@michaeldoherty2289]

This type of cells is deep cycle only. Not a starting battery. They are not built for the rapid discharges needed in starting an internal combustion engine.

[@Mangled99]

Thinking of doing this, it's the active balancer in parallel with the one on the Daly BMS or didn't you bother connecting the Daly one?

[@freelyroaming]

You have to connect the BMS for it to work properly. Active balancer is just connected in parallel.

[@bornex71]

Fantastic series...thank you for this. Question: if I was to put this on a boat, I would need to put a lid on the box. What about heat build-up? Should the box be vented? Or maybe have a 12v computer fan installed possibly on the lid with vent holes in the sides.

[@freelyroaming]

Yes ventilation is always a good idea. But also having a cover to keep the terminals from shorting out is also crucial.

[@Anchor2012]

@@freelyroaming I was surprised that you put in all that foam padding, you basically made it hard to compress the batteries to stop swelling and movement relative to each other, and also made it hard for the batteries to cool down - and it also made you do all that work on DIY busbars when the ones with the proper design (the little arch) for expansion/contraction were there in your hands! Your design seems to me to place a risk to your battery terminals by allowing independent movement from cell relative to each neighbour cell, say from vibration. I supposed time will tell. Thanks for making this video, its got me interested again in making my own. I looked at this about three years ago and it was too hard getting all the parts at reasonable prices.

[@freelyroaming]

I've got an video that explains compression and heat in detail. You should watch that.

[@Anchor2012]

@@freelyroaming Thanks, just watching it now! I am happy this series did well for you. I have watched each one now. Thanks for making it and making it so well.

[@michaeldoherty2289]

@@freelyroaming I have a 240 Ah battery of the same design in a wood box. Remarkably enough there is little heating of the battery even when discharging at high amperage. I have a 2000W Renogy pure sine wave inverter and run a microwave and fridge with it together and see insignificant heating (2-3 degrees C) inside the box even discharging at 140A for periods of up to 10 minutes when using the microwave. I left a lot of air space in my box and even insulated it for cold temps with foil faced 1/2" polyisocyanurate foam sheeting and still it shows almost no heating.

[@meandtee8401]

I would suggest that you move your cell monitor from the back of the box to the front (as viewed at end of video) as it looks awfully close to battery bus bar. On the opposite side there is plenty of clearance and you could rotate monitor 90 degrees and wires would run down between foam and wood box and allow you to lower monitor about a 1/2 inch from the top edge.

[@freelyroaming]

I think you are talking about the active cell balancer right? If so yes, I do think it's a little close to my bus bar for cell 3 and 4. On the other side I have the BMS which is taking up the entire side... won't fit thete. I have wrapped a good amount of high temp tape around the bus bars and the cell balancer to insulate it in case the VHB fails.

[@meandtee8401]

Thanks, yes, I saw that after I viewed your next video. Didn’t realize I was that far behind. Thanks again.

[@smacospasovski5123]

More precise link for the batteries.ty

[@Subgunman]

Interesting storage idea. Most other KZbinrs are compressing the cells together instead of using a spacer in between. Have you checked with the supplier/manufacture as to what is the preferred packing solution? This is definitely smaller than my 200 amp AGM pack which consistent of a pair of 100 amp pure lead Telcom backup batteries. I have a unique situation where I might need 24 volts for a line interactive UPS or 12 volts for operating emergency comms gear. This was accomplished by using 75amp Power pole connectors that look identical to their smaller 15 amp counterparts. Each battery has its own + & - connectors that are latched together in a square configuration. The connector that plugs into this connector determines the output voltage. What is the name of the big box store there in Croatia that you found your supplies?

[@freelyroaming]

Yes I am aware of the compression method and the theory behind why people do it and even why some manufacturers recommended it. I have been asked a couple times about that and there will be a full explanation on why I believe this is the right way for me in the next video. There are a couple chain stores here i go to for supplies. One is called Brodomerkur and another is a German big box store called Bauhaus.

[@lenward474]

Am I misunderstanding? Have seen other bms that has wire to each battery for sensing. This is just in series? Balancer is separate. Is this alternate,better method? Also on his website five choices. Not I understanding the differences. Thanks so much for step by step. Stay safe over there!

[@freelyroaming]

You have a main negative battery connection and a separate voltage sending port. My sensing wires are wired to main negative and each positive post of each cell in order for a total of 5 sensing wires. That will give you the best cell level voltage monitoring.

[@MrGarda42]

Excellent video. Curious tho; why a separate balancer when the BMS does that function already? Or have I missed something 😅. Thanks in advance ✌️🍻

[@freelyroaming]

Thank you. If you watch part 1 of the series I talk about adding this as a test to see how it works with and without.

[@MrGarda42]

@@freelyroaming sweet. When will you know the results of that test? I posted this question on a group of experts too, only two replied so far but the consensus seems to be between “doesn’t matter” and the famous Slavic “why not”. 🍻

[@freelyroaming]

Yeah I suspect my results will fall between those 2 from the looks of it. It really depends on how well the BMS does at balancing cells. I think a real test would be to perform a balancing specific test where 4 cells are intentionally charged to different set voltages and test multiple BMSs and active balancers to see how long they take to equalize. Hard to control the many environmental factors and time consuming to do. Even then, you may arrive at the same conclusion of 'what not'.... 🤷‍♂️

[@Moto290]

You can't hook it up " 6 s " ?

[@larryezell8387]

Really enjoying your videos. You do a great job explaining everything. I am new to your channel, ran across you while looking for info on LiFePo4 battery packs for my solar camping setup. It's probably stated somewhere in all your videos, but you have a lot so I will just ask the question,, what or why are you in Croatia? I expect it is you job and it would be interesting to here about that and you family. If there are already videos on that,, maybe you could point me to them.. keep up the good work on the videos..

[@freelyroaming]

Thank you. Our vlog channel has a lot of that content if you are interested. Our kids appear in them so KZbin disabled comments there unfortunately. kzbin.info

[@freelyroaming]

We also have this one here we uploaded last year that explains our story a bit. kzbin.info/www/bejne/iYvcenigq8ebadE

[@larryezell8387]

@@freelyroaming Hey thanks for the quick reply.. your down to earth tech really hits home with me. I live in Texa and travel all the time and camp in an A-frame pop up camping.. primitive camping (boondocking) is a blast. I'll chack out your early videos..My brother and I have a few vids on youtube, but just for us and out friends,, nothing like what your able to produce. HavefunX10.. Thanks again Mike Ezell on facebook, Alvarado, Texas

[@freelyroaming]

Thank you Mike

[@nigel3809]

Informative video, thanks. I would have used marine epoxy, instead of the screws and the angle bracket. It would have been just as strong and look neater.

[@freelyroaming]

That's great. I doubt it would be as strong or look neater but that's great.

[@michaeldoherty2289]

Very nice video. Professionally done. Some criticism though. Not a good idea to put foam sheets between the prismatic cells. The walls of the cells should be compressed together to prevent expansion of the cells during charging and discharging. They should not be able to expand and contract as you said. I also don't like the looks of the L brackets on the bottom of the box. They seem unnecessary and could rub on and cause damage to the aluminum cells which are not very tough. Doesn't your BMS have cell balancing feature? Most do so the cell balancer would not be needed. Also a plexiglass or lexan cover over the battery would assure that a tool or gear in you battery storage area is not dropped on it causing a catastrophic short. Did you make a wood cover?

[@theeaskey]

What is the actual dimension of the cells

[@bruceburns1468]

Is there a corrosion problem with your copper bus bars and the aluminum battery posts?

[@jupiteradventure5284]

Not yet! 😉

[@jonathonberwimblethwaite6838]

Nice video and informative. I would suggest not enveloping the batteries in foam but use strips which will allow air flow. Your positive and negative leads are the same colour, I hope you put a very distinctive label on them. Your battery switch should be in a more accessible location as you may need to switch off the batteries quickly in an emergency. Why not make a hatch in the bed base to access the batteries from above? Not meaning to sound negative just my thoughts. Thanks for the video.

[@Philips53]

I was also thinking that if the draw or charge on a bank like this is

[@jonathonberwimblethwaite6838]

@@Philips53 if you tape around the whole pack then that will sbill not callow air flow. The warm air needs to escape. On the boats I have worked on we put the batteries in an oversized box and strap them down.the box has a vented hose to allow warm air to escape.

[@jeffma6811]

This is a very clean and straightforward config,however could you use a circuit diagram to explain your idea how to config it out? I also wonder how you choose those monitoring device, what spec need to be considered. Hope you can read and respond, thanks 😊

[@freelyroaming]

Yes I will make a dedicated video to show my exact wiring diagram.

[@jeffma6811]

Thank you for quick response. I am a very beginner, I don’t fave any RV experience before but I am dreaming to give it a try possibly early next year after I retired. I am trying to look around through different web site or KZbin video but sometimes it difficult to understand why people I’d doing this way or that way especially electric system. That will be my most challenge for now because it is not like most wood work inside the van, it might not look pretty but it won’t cause any safety risk. I just finished watching all four video regarding you battery system setup, I’ll check up your blog too and hopefully can see your update soon.😊

[@jeffma6811]

@@freelyroaming by the way, wish you have a great time in Croatia.

[@musimaniac23]

@@jeffma6811 I could not find the wiring diagram in any of the videos... Did I miss it?

[@jeffma6811]

@@musimaniac23 no, I didn’t see it either.

[@monamelte8466]

One more question if I may: What size fuse / breaker will I need for a 48V system converting to 12V in a small RV?...Thanks!

[@monamelte8466]

And. should I go with a breaker or a ANL fuse?

[@freelyroaming]

A fuse will be cheaper. Good quality breaker can be very expensive and the cheap Chinese versions you can find on Amazon don't have the quality control necessary for a critically important component like this. The size depends on the amount of amps you plan to draw. Assuming you are fusing a 48v pack, divide the total peak watts you plan to use by 48 to get the max amp rating you need for your fuse. For example, of you have a 3kw inverter, that will draw 62.5 amps from a 48v system. Add 10% in for overhead and you will see a 70 amp fuse is about what you will need.

[@monamelte8466]

Which fuse would be better for my application? An ANL fuse, a terminal fuse, or whatever other suggestion that you might have. I can't seem to find a 70 amp fuse in either whereas an 80 amp, MRBF terminal fuse is available. I have a camper with standard 30 amp service and 60A charger controller....thanks!

[@monamelte8466]

Looks like I am able to find a 75 A terminal fuse, will that suffice??

[@freelyroaming]

I think that will be fine as long as you size your cables to comfortably handle 75A if current.

[@injeraguru2216]

The foam is nice for cushioning, But does not allow for adequate heat dissipation...I hope your BMS comes with a temperature sensor

[@freelyroaming]

In this application where 0.2c is the max discharge rate there will be very little heat.

[@monamelte8466]

Dan, do you have link to a good battery box kit for 280ah 3.2V x4 = 12.8V?

[@freelyroaming]

I built my own wooden box. It's difficult to order something that fits your needs without seeing it in person.

[@monamelte8466]

I am sorry, I was looking to build 12.8V, 280ah, portable power station that I can build into a tool box or similar.

[@pipparola]

fantastic job! how much did you spend for all? thanks

[@freelyroaming]

Thanks! I break down the full cost in part 5 kzbin.info/www/bejne/rKOsoamraNeChtE

[@pipparola]

@@freelyroaming thank you

[@TheOriginalCoda]

Good series so far, just subscribed. One comment though, electricians (in the U.K. at least) will be grimacing when they see two DC voltage conductors colour coded with green/yellow which means Earth bonding/Ground. We’re very anal about that sort of thing ;)

[@freelyroaming]

Thank you. I hope electricians are also anal about checking actual polarity with a multimeter each time before making connections instead of just trusting the color of the wires. For all you know, the last person who worked on it has color blindness. 1 in 12 men in the world has it.

[@zain-zeus]

Can they be charged directly by the alternator ? or only DC to DC charger ?

[@freelyroaming]

I would not charge directly from the alternator. I know there are some people who do it. I use a 20A dc to dc charger with a lithium specific setting.

[@jws3925]

did you not like the buss bars that came with the batteries?

[@freelyroaming]

Not long enough to allow me to add spacer between the cells.

[@jgazaway4944]

Can you please provide the specifics of your bms that you used

[@brianmi40]

search DALY 4s BMS on aliexpress and choose the size and whether you want bluetooth

[@jgazaway4944]

@@brianmi40 I am sorry for the late Thank you. I have got to learn to go check all my gmail folders.

[@brianmi40]

@@jgazaway4944 No worries, you're welcome. I'll be installing my 200ah DIY battery with a Daly BMS later this month.

[@mausie1967]

Great video, but indeed, too bad you didn't show the most important thing,.... how to wire everything up. Greetings from Holland

[@freelyroaming]

Thanks. I will be taking this apart and upgrading this with temperature controlled heating pads soon and will show the complete reassembly video.

[@benjones8977]

Isn’t the Victron battery sense redundant? I thought most of this is in the Victron shunt?

[@freelyroaming]

The SmartShunt can sense temperature but you need to buy a separate thermistor accessory which is about half the price of the battery sense. It is not included with the SmartShunt. I would have done that instead except I already owned the battery sense before deciding to buy the shunt.

[@ebukaedenenergycontractors3268]

Is the shunt a need in the battery configuration?

[@benjones8977]

@@ebukaedenenergycontractors3268 I do not believe so, but after you’ve had it you realize you don’t want to be without it. It’s like driving a car without any mirrors.

[@brianmi40]

Since the active BMS is metal encased, I would do more than use doublesided tape to adhere it from coming loose over months or years of bouncing around in a van. It looks large enough to easily span between positive and negative terminals which would be disastrous. Also not clear why you chose to leave so much unused length on the individual cell wires...

[@freelyroaming]

I assume you mean the active cell balancer. It's also screwed down. You can see that in the other videos. Sensing wires are best if they are all exactly the same length if you want the most accurate reading. If one is longer than the other you would have more voltage drop from that cell. It's especially important in this case as you are comparing differences in millivolts using very small gauge wires. So you should keep all of the wires the same length as the longest one you'd need to have. But these are very nitpicky items really not worth anyone's time to talk about in such a high level build video.

[@aaronreagan9223]

What was your total cost for the build? Thanks!

[@freelyroaming]

I will add up all the costs in the last part of this series which should be by this weekend.

[@newmiziri]

Hello Something still no clearer, how balanced

[@freelyroaming]

I am making a dedicated video soon about different balancing techniques and reasons.

[@newmiziri]

Hello, thanks, u made very complicated I'm lost, I want to make too Bro u have connected all batteries together via bus bar. Then BMS wires connected to all. My question is technical how u are balance control on batteries

[@Moto290]

So you don't believe you need to "compress" them?

[@MrTubeman007]

Your Victron battery temp sensor should be stuck to the battery body not the wood side.

[@budmartin3344]

How big is that copper pipe? 3/8"

[@freelyroaming]

Well it's a metric pipe but it measure to about 1/2 inch in outer diameter

[@acmeopinionfactory8018]

@@freelyroaming So, yeah, it's probably about 3/8" inside diameter, which is how it's sold in the US, not O.D.

[@jimurrata6785]

@@acmeopinionfactory8018 The U.S.standard is that threaded pipe is nominal ID, but tubing is sold nominally 1/8" larger than designation. If you're buying copper that's straight or annealed in a coil it is tubing. There are not three different sizes of sweat fittings for 1/2" K, L & M tubing, they are all 5/8" OD, but M = 1/32" wall and K = 1/16" wall.

[@giuseppeloprevite7256]

Hello...can I close the box or Must I leave open??

[@freelyroaming]

It is best to close the box with a tightly fitting top to better regulate the temperature and protect the battery terminals.

[@giuseppeloprevite7256]

@@freelyroaming Is not a problem for the bms or shunt (don't product hot)??howewer with a wood top Is good??

[@freelyroaming]

If something metallic falls into the box and shorts out the terminals you will have a big fire. So if that is a possibility, protecting the top is a must.

[@giuseppeloprevite7256]

Thanks a lot

[@GluttonywithaGerman]

From what I understand the cells should be compressed to prevent expansion. So I feel like enabling expansion is degrading your cells unnecessarily. CATL Battery packs pack cells close and tight for vehicles.

[@freelyroaming]

I have a video that explains compression in full detail.

[@freelyroaming]

kzbin.info/www/bejne/iJC4o5VoarRkp8U

[@ltldevl]

If you build another box, use glue instead of screws.

[@freelyroaming]

If you don't have a way to make really clean and straight cuts like I was dealing with here, glue will not hold. This does and there's no need for another box.

[@JohnBraman413]

280ah total or 280ahx4 total?

[@kenworland2682]

The batteries are 280ah but only 3.2 volts each. Connected in series, together they will be 280ah but at 12.8 volts.

[@twlyons1]

🌟🌟🌟🌟🌟

[@Anchor2012]

Where is the fuse?

[@freelyroaming]

Circuit breaker. Watch part 4.

[@johntemp1692]

Why did you put the foam between the cells? Seems totally unnecessary. I live in the desert and those cells won’t expand unless damaged

[@freelyroaming]

They will indeed swell significantly when they are damaged. They will also expand slightly under normal use, especially in high temps. In fact even the manufacturer recognizes that as they have enlarged one of the bus bar holes to allow some movement. Personally I don't believe it is enough. The M6 terminal post hardware is woefully weak. The amount of expansion has the potential to bend and distort the terminals. It is a simple and easy insurance to prevent that from happening so why wouldn't you do it? I see people trying to avoid the expansion by forcing the cells tightly together using clamps. That does not seem like an ideal solution. Giving them room to expand and contract is the right way to do this. Preventing expansion from chemical reactions by force is never a good idea. And in case there is for some reason a catastrophic failure event and significant expansion happens with the cells, building them this way will prevent it from causing further harm.

[@georgedemean2228]

​@@freelyroaming Try to maintain the cell's temp between 10 -35 C (No cell swelling at this temps and long life) If the Temp exceed 50C it will get damaged just as bad as at below 0 C Charger/Discharged

[@acmeopinionfactory8018]

@@freelyroaming Seems to me that if the oval hole in the bus bar is to be of any use, the terminal screws are not tight, which leads to resistance. The oval hole is for some other reason, perhaps to compensate for slight variation in the manufacturing of the bus bar.

[@Anchor2012]

@@acmeopinionfactory8018 This is correct. Also it is to allow you compensate for all kinds of other tolerances at installation time - not to allow movement later. The arch in the bus bar is the part which allows for partial compensation for movement and for the metal expansion contraction in the busbar.

[@DanBurgaud]

4:34 I am not fond of these installed here inside the box. 6:45 Hmm.. I would have added a 25mm wire inside.

[@freelyroaming]

Not enclosing them in a box for a mobile setup is a terrible idea. But you do you. What size wire you use is completely based on expected amp draw and length. Generically recommending wire size without knowing its application show some lack of knowledge on the topic.

[@DanBurgaud]

​@@freelyroaming Take note of the timestamp in my earlier post and I will repeat it here for your understanding. 4:34 I was referring to the metal "L" supports inside the box, not wooden box itself. (ok perhaps I did not state that clearly above). BigBattery had an issue with weld protrusions inside their battery case that caused a batch of packs to puncture the cells. 6:45 I am not taking about using 25mm2 wire as flexible busbar, nor as main battery cable. I was referring to the flattened copper busbar you did here. Is that even comparable to the actual busbar it was replacing? NOPE! Having additional 25mm2 wires inserted inside that flattened DIY copper tube busbar will make it more conductive. tsk tsk. "Generically recommending dumb solutions without knowing its application show some lack of knowledge on the topic."

[@freelyroaming]

Sure I noted the timestamps. the brackets are not close to the cells. Big battery had other issues that cause their punctures. It had to do with their enclosure. I am in direct contact with them about their products as I am currently reviewing one. You are once again, using only 3rd hand knowledge which are not reliable to anyone who knows and matters. The copper pipes are more than sufficient. Especially since the originally ones no longer work as they are not long enough. You have no data to base your argument against using them. I will say again, these show your lack of knowledge on the topic. You have no proven track record.

[@jeffallen3382]

And how is those copper pipe squished down any different than those laminate bus bars that came with the batteries? LOL Sorry man this is a hack build!

[@s.v.gadder1443]

If you're gonna make bus bars that way I'd just crimp each end no need to Flatten the whole thing .....

[@freelyroaming]

No you have to flattened the whole thing because they don't fit flat against the terminals and you will not have enough contact surface otherwise.

[@miketipping1583]

Why did you skip over the actual assembly of the battery and configuration of the BMS? I'm sure those are the things most people who watch DIY battery builds are interested in rather than how to make a wooden box or flatten copper pipe.

[@freelyroaming]

The timelapse on the camera didn't record and I only found out afterwards. I'm gonna make another video about the assembly process with diagrams for anyone who wants to know how to assemble it.

[@miketipping1583]

@@freelyroaming that's good thanks. I've been looking for a decent BMS but most of the KZbin reviews of AliExpress ones seem to be bad so was interested to see yours.

[@jgazaway4944]

I may missed the video, have you made the video yet

[@raybacchus1026]

I just waist 14 and something minutes watching dis video u didn't show us how u wired up the battery not nice ..... but good video tho

[@1975Per]

You should never get any swelling of the cells due to warm weather. Swelling of the cell is indicative of a broken cell that could potentially cause fire (not so much in lifepo4) will have significant lower capacity, and should be replaced/discarded. You're wasting time and effort taking this into consideration.

[@freelyroaming]

That is an extremely general statement. What is warm weather in your opinion? The manufacturer has a recommended operating temperature and since this is being installed in a vehicle, it can get extremely warm as compared to a building. It is common knowledge that they swell in excessive heat and they also expand and contract naturally during charge and discharge cycles. It is not a sign that they are broken. You can certainly skip this step if you don't have time to waste.

[@1975Per]

@@freelyroaming I was thinking of as hot as weather can get anywhere on earth. Now you mention an engine bay, that is not "weather", and is why you shouldn't have these cells there, they can get got. And that kind of swelling frlm that hot will damage your cells and not normal operation. I have yet seen any onther DIY or broken apart lifep04 manufacturer do their build to take into account swelling. Where have you seen this? Most strap them together pretty much as tight as they can. For other types of lithium cells, swelling is even worse, as it usually is a sign of a runaway fire coming soon.

[@freelyroaming]

LiFePO4 does not have thermal runaway issues that other lithium chemistries have. And no, these cells are not in the engine bay and did not mention anything about that. These will live in the temperature controlled part of our van where we live.

[@1975Per]

@@freelyroaming I know that lifep04 doesn't have thermal runaway. That's not what I meant. So, if this is not what you're trying to avoid, what is the expansion your're talking about, that you're trying to avoid? Like I said, I've never seen anyone ever trying to avoid, or even talking about, expansion of lifepo4 cells, and trying to build in room for that swelling. (no matter how hot the ambient temperature from the weather is). Most people even use metla straps to strap them together, leave little or no room whatsoever. SO, I'm trying to figure out where, or how you've come across this information that you should leave room for the to expand, like you're building it. I've spent ALOT researching how to build my future battery, hundreds and hundreds of hours of videos of people building, tear down of battle born batteries, other brands etc. And never seen it. So, if I've missed something, I'm very interested to find out.

[@freelyroaming]

Since it seems you've done a fair amount of research on this topic, you'd know there's a fair bit of controversy around it. Enough people have asked that I will explain it in more detail in my next video instead of trying to type this out every time someone asks in the comments.

[@chrischwalik1625]

Thanks for skipping over actually doing the wiring which is why I watched the video in the first place. So not so great for me.

[@powderpuff1964]

after trying to read chinese instructions on battery balance i seem to understand you need 1 for each cell iie 4 many thanks colin

[@michaeldoherty2289]

Yes indeed. It is a 4s configuration (4 in series cells).