Is Lifepo4 A Fire Risk?! How To Make Safe Battery Connections.
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- เผยแพร่เมื่อ 12 มิ.ย. 2024
- A lot has been said about the risk of building our own batteries. The biggest risk involved is in making poor connections. Let's talk a bit about that. Making correct joints and crimps and torquing our terminals correctly is important. I also discover the dirty trick played on me by the battery cell supplier when they sent me brass busbars instead of copper. Next time maybe we need to address wire sizes and fusing and breakers. Let's keep it safe y'all.
I am now 10 fold more paranoid about the battery bank I built 😂. Time to go back and redo some stuff. Thank you for explaining all this in a way us novices out here can understand. And thank you for not drowning it in cheesy background music. This is one LEGIT presentation.
😂
I was really impressed to see what actually a "gas tight joint" is.
Thanks a lot!
I misspoke in the video when I said the copper busbars were equivalent to 1/0 copper wire. I meant to say 1 gauge. Not a huge difference but I wanted to note the correction.
Great video. Pure copper busbars have a current carrying capacity of 1.5*CSA (mm2) , which mean your busbar can handle abt 60Amps.
You might better pin this comment that is stays on the top of all comments that people get aware of it without having to scroll through all comments.
1 tiny point that this is wrong cause you had calculated your busbar with the equation 20 mm x 2 mm = 40 mm² which then would equal a 7 mm diameter wire which equals 1 gauge, but
if you drill a hole of 3 mm in that busbar everything changes from 20 mm to 17 mm x 2 mm = 34 mm²
squareroot of ( 34 mm² / pi ) = 3,3 mm radius or 6,6 mm diameter which is a 2 gauge wire, not 1 gauge.
Your hole of 3 mm (my assumption - could be 2 or 4 mm) diameter weakens the conductor property.
The only counter argument is the terminal hole cause the contact surface is below and above and around the whole terminal. Which then would mean to be precise that the 20 x 2 calculation is completely off due to the bigger holes of 1 cm not just the 3mm hole unless the surface of half of the nut and its bottom counterpart is bigger than the squarespace of the bus bar cause the power will flow the shortest from the lower terminal surface up into the busbar and from the nut screw surface down into the busbar.
Does the 3 mm hole lower the conductivity of a bus bar might be a question you could answer by measuring the resistances from a screw with 2 nut screws that fixes the busbar on each side.
From such arteficial terminal screw to the other you can measure the resistance for a busbar without the 3mm hole and with the 3 mm hole to get behind the impact of such hole.
And this might also change the answer to the question what awg size such 20 x 2 mm busbar equals depending on the 3 mm hole or not.
It's really very informative, could you please explain how to calculate the busbar size for the battery?
You misspoke as well when you said you can't sand the busbars down to make them flat. You put the sandpaper on a mirror and do figure 8's with the bar. I just saw it done yesterday and a heat camera was used before and after and the temperature dropped significantly. Just needs to be done on a flat surface.
@@felonebike9859 so they sanded through the tin coating?
The tip on attaching the balance leads mid point on busbars so they don’t interfere with torquing the bolts is very good. Thanks!!!
Thanks for pointing out how big a difference there is between copper and brass. Wow! I'll be checking what they send me.
Ray!...i believe the fact that u are very able to teach young generation of electricians.
Beside of your knowledge u have also another virtue...to be patient.
Good job!
I think I just found my latest favorite channel!
You made me smile.
Thanks for passing on such great advise and saftey tips. Also verify the wonderful connection advise with a temperature probe on all connections points under load for 20 or so minutes and verify it’s not to high above ambient.
Thank you for your perfection and your will to improve on something..l am a 54 years old master carpenter and l totally understand everything you are trying to do..
Thank You! As a degreed electrical engineer, I learned about theory. However, your practical tutorial is far more valuable. Fortunately, I had a very good theoretical professor before you. He said, "Always keep learning. Theory is good, but practice is best."
Your comment makes my heart warm and your sentiment is why I have made these videos.
I LEARN SO MUCH FROM YOU....AND HUMILITY IS DEFINITELY ONE OF THEM!!! IT IS AN HONOR TO HAVE COME ACROSS YOUR CHANNEL RAY!
Honored to have you and to read your comment.
holy crap - i didn't know BRASS bus bars were even a thing! thanks for the heads up/info. i'll definitely be checking mine when they get off the boat...
Having built sport boats in the past for a 15 year stint, I tend to agree with the use of a flexible connection between battery cells. Marine applications are a very high vibration environment subject to twisting loads that would certainly stress these terminals. Terminals that seem barely adequate for home use, let alone in boats where they will really take a beating, and high moisture exposure as well. It may very well be an ABYC (American Boat and Yachting Council) standard to use a flexible connection here. Have been away from industry for far too long to be certain. Maybe some others currently in the Marine industry can chime in with current standards. Thanks for all of your attention to detail, and the information you provide! I enjoy your videos very much.
My projects just took a turn for the better. Thank you for sharing your wisdom. So many of these build videos on TH-cam are lacking the basic analysis you have done. I am a new sub.
You are a pecfectionist, Ray. I really admire your "attention to details" in building your project, where others fail to consider. I learned a lot in this Vlog! I just subscribed to your channel and would like to learn more. Thank you very much!
Thank you Jojo. I think this part is really important. If you size the wires right, make good connections and protect it all with fuses, I think the risks are dramatically reduced.
Preach it dude! I absolutely agree! I did a lot of work for people that if not done properly could have made them ill or worse. I had a gentleman that worked for me that was from Poland where he learned a saying that I really appreciated. The saying is, Aim for the stars and you'll at least hit the moon. I can think of plenty of circumstances when I was doing something for myself that good enough was okay as a temporary fix. But, good enough is never an option if it leaves the possibility for tragedy.
Ray, what a great video! I´m working professional as an expert for connectors in the automotive industy and I can sign every word from you! Especially the criming is in my point of view the most dangerous part of all. I have all the tools to do it by myself, but I didn´t want rely on it and ordered all the battery cables in the length that I needed with crmps from a hydaulic machine - all crimp parameters are controlled - there are alot! It was worth to me. Again THX for the good video an discussing that stuff!
That's the work of a perfectionist ! I like it ...
I love this attitude and the awareness with concern of details.
Solid advice here. Worth the time spent to watch in full. Thanks for posting
Great video, Ray! I always taught it's all about means, methods, and materials... and you will always have quality results!
If perfection makes the difference between no harm and harm/death, a little more time, a little more money and the more attention to detail is a small price to pay. I have learned a lot via your explanation in just 2 of your videos. Great work.
Thank you for making this video. You made a very good point on wire and battery connections and I found it very helpful considering that I am planning on building a 48v battery bank as my diy project I want it to be correct and as safe as can be. I been watching tons of TH-cam videos on this subject and find your to have made good and sound sense. I am now a new subscriber to your channel. Thank you again for taking the time to share your knowledge.
I now understand the importance of good connections, so I'm off to get some new tools. THANK YOU!! for making my project safer than it would have been.
Extremely helpful video, Ray. Thank you for covering the bus bars. I will be checking my bus bars because you put this video online. Will try to emulate your example.
This is entire video is filled with great advice...thank you.
Great info, Ray. I just discovered your channel & I’m really digging what your doing. Thank you for taking the time to film your work share your knowledge.
God bless you, bro
Thanks Andrew. I'm sorry I don't spend the time to edit them and make them more entertaining and polished like the other channels but I spend all day every day working on this stuff and I decided it will just have to do. Sometimes I wish I could offer more than just the info I compile and implement but I guess you can't teach a fish to climb a tree. I'll just have to be satisfied with swimming. lol Thanks for joining our little group.
Excellent commentary and experience that cuts to the facts quickly. Well done and thank you!
So happy you found value. I hope to find time for more videos soon.
Thank you for all the information you give us. I knew that "big wires" are important, but I would never have come to the idea that corrosion is such a big risk. That should remind everyone to check their batteries and all their connections regulary.
Good video, I have not seen anyone talk about connections as you have, Thank you very much.
I am just starting out on a solar project with very little experience in anything electrical. I have read and watched so many decent videos but needed this reality check of the dangers and the perfection that needs to go into everything.
I like your attention to detail
I've used Kopr Kote as it actually contains copper (not it's intended use however). Once that has been shrink wrapped, I'm betting it will last a long, long time. I'll really have to put that to the test beyond just using it on the battery terminals on the truck though (which are obviously fully exposed, in my salt air environment). Noalox might work as well due to the different types of metals involved.
You continue to provide excellent and meticulous information for people and I'm thinking you should have far more subscribers (doing my best and liking all videos).
Thanks
I really appreciate all the hard work and education you're giving me and I agree with you if we practice for Perfection we're as close to perfect as we can get when we fall short cuz no one's perfect
Love your comments. They lift me up.
I love this video! This is the kind of info that we don't normally see. Would love to see a video of the crimper in action! and the type of lugs you are using.
I normally say to people i talk to.
In Denmark its not allowed to do electrician work by yourself, but if you do. Do it better than the electricians!
Im an former electrician and now wind turbine electrical design engineer of the biggest turbines. 15MW++ where we have thousands of amps in our busbars.
I really enjoy watching your videos! Thanks for sharing!
That's some cool stuff sir. Thanks for sharing right back at you.
I love those drill bits with threaded inner. Nice routing for the busbars.
Ray, thank you very much. Bless you and your family.
Great video!! Lots of good info here - more people should be seeing this. I never understood the soldering of lugs. So many people tell me to "crimp then solder" and I'm sitting here thinking... well, if you crimp it properly, it's solid so where do you expect the solder to go?
Thank you for watching. I would love to see more people benefiting from what I am learning and what my 40 years of high end construction might add to all the great info that is currently available. Love your channel by the way. Keep up the good work.
Those guys are simply selling solder and soldering equipment cause the tin will melt and a bit will move into and look the soldering look tinned and shiny bright.
you will not have a benefit except it looks good and what looks good makes you feel good unless you have the knowledge that it does not improve anything except the profit of the tin and soldering shops.
Great content, recently upgraded my tools as a result of a electrical position with Earthroamer. Quality tools for life.
Excellent video and information. Many thanks.
Excellent tutorial even for the more expert one of us because, as you said, good is never enough and only perfect can lead to no trouble (we hope) I really appreciate your work 🙏 and I will stay tuned 😊
Incredibly useful information - thank you
Subscribed! Wonderful content and a one of kind teacher!
Hi Ray , I love the passion you have for this and helping people like me with very little knowledge on building batteries . The reason they have thin wire on overhead distribution systems is because they run at high voltage, when volts go up amps come down and no need for big heavy cables in the air, that's why they have the step down transformer boxes . I'm in no doubt that you know this already 👍
That is a big part of it and the other part is that they are uninsulated so heat is not as big a factor and in the air, the heat disapates better by radiation and convection. Thanks for your kind words of encouragement.
As a ham radio operator we have to look at great connections to get the lowest swr points for the coax and antenna connections, radios are expensive so great connections are a must. Power supply connections are also very much necessary. The info you put out is not only good but it is excellent info that can be used in high energy hobbies.
Wow, I am humbled by your kind words.
Excellent content well delivered. I used pre manufactiured tinned braided 250A earth straps, onto aluminium studs and noalox, in a RV setting. Cells are under slight compression forces though, so shouldn't be going anywhere no matter how many years of jostling the van takes. Hoping the 'braiding' dissapates the heat better. Maximum i should be carrying is around 100A on a 24V setup.(like a good margin of error, means you sleep better at night).
The torquing of the lugs onto the cell studs though was a nail biting moment each time. :-)
(This was before all the 'welded' studs were available on the cells(which i'm not a fan of anyways).
Awesome video with a ton of great info for people new to batteries.
Glad it was helpful!
Thanks for the experienced knowledge we all need it. Don't feel bad about the bus bars there are a lot of people out there that love to cheat us out of our money.
Thank you sir.
I wasn't even aware there was a brass variant of these busbars. I guess I'll be checking through mine tomorrow...
This info is critical, so thank you Ray.
Good advices. I used solid copper bus bars, washers and nuts all over the battery. We are dealing with 300 amp. No need to say more. Even the connections between BMS and battery are made in solid copper bars. Same for connections from battery to inverters. No cables for 300 amp! It requires bending copper bars, but copper is soft...
Thank you Ray good explanation of conductivity. Iam retired now but on my first jobs was in electronics for companies for Boeing and Lockheed there cables conductors were mil's specs, usually copper plated an alloy of nickel and platinum, teflon insulated. In avionics weight is critical so the look for best alloys to minimize resistance in a conductors in a lesser gauge wires I was amazed.
Thanks for sharing Ernesto.
resistance is always determined by the bottle neck not simply by measuring the 20 mm x 2 mm = 40 mm² area considering the amount of direct contact surface with the battery terminals can be smaller.
If that contact surface area would be smaller than that terminal is the bottleneck.
What is the real contact area of the terminal considering the nut is smaller than the 20 mm busbar?
Assuming you have a 10 mm diameter terminal and a 13 mm ring surface on the terminal and a 13 mm outer diameter of the nut screw (with of cause 10 mm hole) you will have 2 same size contact surfaces each calculated with the radius as half of diameter
= ( outer radius ) ² x pi - ( inner radius ) ² x pi
= (outer radius ² - inner radius ² ) x pi
= ( (13/2) ² - (10/2) ² ) x pi
= (6,5 ² - 5 ² ) x pi = 17 x pi = 51 mm²
This means you will have 51 mm² contact surface on the bottom terminal + such nut screw or 102 mm² and therefore the busbar squarespace of 2 x 20 mm = 40 mm² will be the bottle neck unless you get a 2,5 thicker busbar plate which would mean a 5 mm thick busbar.
To be honest: 5 mm thick would not be enough
Why ?
The 3 mm hole lowers the squarespace from 2 x 20 mm to 2 x 17 mm which then means 34 mm² instead of 40 mm² which means a 3 times thicker busbar of then 6 mm x 20 mm (net 17 mm due to the hole)
But that 5 mm thick 20 mm wide busdbar would equal what copper wire thickness ?
102 mm² is the total terminal surface and a cable of ( 102 / pi ) ^ (1 / 2) or bigger would push the bottleneck to the terminal. Remember that ^ 1/2 means square root, so squareroot (102 / pi) = 5,7 mm radius or 12 mm diameter copper cable
That means a 12 mm diameter copper cable ( 4/0 AWG) would equal a 20 x 5 mm copper busbar if the joints are perfect.
If you think twice you will realise that this comes close to a good 24 V jumper wire cable used for semi trucks or cars.
But that all depends on terminal and nut screw diameters and has to be taken into account to get the best solution.
Copper is expensive and therefore the chinese master lier dealer from the first battery batch order did work again on her reputation considering that the batch had arrived without busbars and needed a complain to be shipped.
And those copper busbars come tinned cause tin looks better than the old oxided copper which makes it easy to fool us with tinned brassbars instead of tinned copperbars.
China is called communist state but their dealers can be the most capitalist one you had seen sitting behind an iron curtain cause none chinese customer will no go to court.
much food for thought...............thank you!
Great tips and information! Subscribed! Glad I found this!
Welcome! Thanks for your kind words.
I bet your wife is super proud of you. keep up the good work and research development. I just subscribed I just came across your Channel
Thanks, I hope the videos help. You are right about my wife.
6:58 on the few best advice you ever get in your life
what a wonderful video - you're great bro. thank you :D
to deburr the hole after drilling and tapping, get a small countersink with 6 or 8 flutes and just spin it in the hole by hand, with a small amount of pressure.
great info, btw. Thanks for all your videos.
I tried several methods of deburring the holes but by the time you use a countersink on both sides enough to remove the burr, there aren't enough threads left.
1.5 speed is ideal 🙂
Thanks for all your videos
Very interesting video!!
When I make battery cables for our farm trucks and tractors I use both crimp and solder to maximize the conductivity. First I crimp like normal and then I drill a hole on the ring side of the crimp and fill the end with solder. Leaves no space inside there for corrosion on the terminal side. I've cut open enough battery lugs to realize a crimp alone often can't be trusted....because eventually you see the green corrosion form on both sides of the crimp. For a battery like this inside away from the extreme weather conditions of a tractor or farm truck I wouldn't waste my time with solder....but I always solder connections on a battery that will be outdoors.
What an excellent vid!
Just be careful with split ring or star washers, in damp areas. I help write a paper on that years ago. The washers got white material on them causing high resistance.
Very thorough. You can solder after you crimp. Could be a good idea if you are protecting from corrosion. But you don't ever want to solder before crimping.
So they put the buss bars in for free right? You got what you paid for. Aluminum buss bars might do better mating to the aluminum terminals. Good idea on tapping the bars for the small ring terminal.
Thats a bugger with the brass bus bars, I almost bought a bunch of CCA wire (Copper Clad Aluminum), the sellers boasted the copper part but man it was cheap. Now i know it exists i check carefully. Same with bus bars, they say they're copper but somewhere in the description it says brass.
thank you
After watching about a dozen of your videos I have about 3 million questions but I also have a shoe string budget
I think I’m going to like this channel.
Thx. I use 1/0 welding cable minimum.
6:06 I have long ago preached solder as the better connection.
However if one considers the fact that LEAD or TIN has lower conductivity that Copper, then press fit is much better.
Hi Ray...I'm another keen viewer from Oz...loving the very informative and laid back presentation. I thought you might have made your own busbars out of tin plated copper bar to your own specs?
I would like that very much but the cost is prohibitive. I estimated it to be about 3x the cost which is in line with the gentleman on the solar forum that was making them in his shop with a laser cutter and having them tinned by a third party. He was selling them for 6.50usd but soon gave up the venture. It's a balancing act but we have to avoid letting perfect be the enemy of good enough. I'm glad my presentation didn't put you to sleep. My wife uses my voice as a sleep aid. lol
@@RayBuildsCoolStuff This is a cut and paste from PowerPaul Australia Facebook page, a lot of info on his page: Bus Bar resistance comparison.
In the picture are 7 bus bars. The bottom 2 are original ones supplied with the 280Ah cells and they are both 15 x 2mm copper, one os nickel plated. The nest 2 are the 2 sizes I had made from aluminium, and they are 20 x 4mm. The top 3 are the new 20 x 6mm bars or the Mercury battery.
The bent bar replaces the entire B- cable assembly that comes with the Daly BMS. That assembly measures in at 0.17m Ohms.
All measurements are from the mid point next to the holes.
Copper - 0.06m Ohms (Original)
Nickel plated copper - 0.06m Ohms (Original)
20 x 4 Aluminium - 0.05m Ohms (Scout)
20 x 4 Aluminium (longer) - 0.09m Ohms (used for complex systems)
20 x 6 Short - 0.02m Ohms (Mercury)
20 x 6 Long - 0.04m Ohms (Mercury)
20 x 6 Bent - 0.08m Ohms (Mercury)
If we extrapolate out the numbers a bit. On a 12v battery which is 4S, and drawing 100A, we will get these losses overall.
Copper - 0.52m Ohms = 5.2w
Nickel plated Copper - 0.52m Ohms = 5.2w
20 x 4 Aluminium - 0.49m Ohms (Scout) = 4.9w
20 x 6 Aluminium - 0.38m Ohms (Mercury) = 3.8w
A 4w loss when you're drawing close to 1300w is an excellent number. It'd be interesting to see what the figures are inside off the shelf batteries.
Now these numbers seem not a lot different, and are indeed very low, but they just show the incremental improvements that I'm trying to include with each new version of battery. I didn't make a battery with the regular bus bars from the start, and the newer version has a greater than 20% improvement already. These sorts of marginal gains are increasingly difficult to get at this end of the scale, but it's a fun challenge.
These figures are losses across the connection points within the battery box. There will be losses within the cells and the BMS to add into the equation too.
The biggest difference I've seen with using these Aluminium bus bars, is the MUCH better connection they make with the battery terminals. The electrical connection seems to be much more stable and reliable. And the mechanical connection has been reported to have eliminated people issues with bolts loosening during vibrations. All of these factors play a huge part in how well the battery works, and have reliable it will be long term.
@@michaelivory7606 Thank you very much for posting this. These values are nice validation for the data I have accumulated so far but add numbers for aluminum that I haven't tested. It also agrees with what I have found elsewhere. I appreciate that you took the time to post this. I think several people are wondering why we try to achieve low resistance values. It appears to be important in getting good results from these packs and the BMSs that keep them in balance. Long term reliability and performance is the goal. This is what my latest video is all about.
Hey now sure if you have already done it. But I would be great if you can teach us how you make those 1/0 gauge cables with the hydraulic wire crimpers. A video on that would be great.
My application is a little bid different. Its to build wiring upgrade for Amp and grounding cables wires. But you are right its important to ensure your crimps are of good quality.
I already have a video about that. Check it out.
Aim at equanimity then perfectly executed practices are possible!
Obviously you are a man I should share time on the porch with.
For sure it is a Fire risk.. unsolid connections cause plasma sparks.. FOR REAL.. very good topic … SOLID connections .. life story ;)
I use a corrosion prevention treatment on my equipment, KC2-AGT Thanks
Good info thanks
Glad it was helpful!
I have sent this over to BBI , he does lots of heavy DC work for communications equipment.
I think the step up to LiFePO4 from lead acid may cause folks to get "current drunk" and it needs to be restated that higher current and higher voltage, as you scale up all present increasing problems that require increasing diligence to offset the increasing risks.
On risks. Here is a bit of bad judgement. When tightening my small 105Ah 4S pack's bus bars I lifted a ratchet spanner. Not the rachet and socket. I even said to myself out loud, "Don't do it. Get the right tool.", but I went ahead and on the 4th tightening I shorted a cell with the spanner. This not being the first time I have shorted a high current battery I knew the drill pull HARD! The plating on the post and the plating on the spanner will weld together, you have to put your weight into pulling it off.... do it EXTREMELY quickly too as in a matter of seconds that spanner will be cherry red and you will have a fire or cell explosion imminent, unless the battery internals are designed to fail as is often the case before the cell would be driven into runaway melt down. The connector tabs and the insulation between them can be design to fail, short and effectively destroy the battery without the explosion.... you hope.
hello ray, thanks for this video, I learned some things.
I would like to tell you that I don't agree with the resistance measurements that you make, I think that the resistance should be measured with an equal length, I would be curious to know the difference in resistance between a rigid and flexible bus bar of the same length, in copper of course. Thanks for what you are doing.
The 280 Ah EVE cells I buy have 2 studs on each terminal, and on top of that I use oversized cable for bus "bars",so I don t have to waste time on all this back and forth, if something in spite of this, not likely, should create a bad connection,it will be easy to feel if getting warm on the highest charge/discharge rate you need,test with temp gage now and then,most likely the hot spots will be inside bms.
Nice video,I've sold over 500 traction forklift lead acid batteries,we used to weld the lead( pb)connectors to lead terminals with oxy acetylene torch then whilst hot we would smear vaseline to protect the terminal before we put the insulator. ive seen my batteries twenty years later and they were as shiny as the day they went out never a single problem,then the batteries became bolt on..long story short it was a total disaster..but just to give my opinion on your Anderson battery connectors I always just flux soldered them,we were doing serveral per week and again no problems,I find the crimp can very easily deform the shape of the pin those pins are spring loaded for contacting each other and any deformity can change this spring pressure/ alignment and cause burning... anyway, that's just my input for what it's worth! Good luck, Paul from Ireland.
Thanks, I will test the resistance through the Anderson connector.
Like the video. Very well presented. I got a simple question…. You know how most BMS’s have a couple of cables for their input and output… how to properly determined the correct size lug to use? Let’s say two 7AWG; which size lug to use?
There are charts that show the cross section of different wire sizes. For instance, if you look at the cross section of a 4 gauge wire and multiply it by three you get a combined cross section that is very close to 1/0 wire size so I use that size lug when joining three 4 gauge wires in one lug. Is that what you are asking?
@@RayBuildsCoolStuff Yep! Thanks. So it would be base on the cross sectional size of each wire. It makes sense!. Again thank so much.
👍🤗 Gut Video
They make nice flexible busbars…. REASON …allow FOR expansion/contraction of each to minimize terminal stress. Specifically I am going to compress battery bank to 12psi and use rods with compression springs to keep them constant pressure parameters.(8-17 psi) However looking at copper chart I would need about 6mm for my EVE304, 300amps. I’m going with 2/0 welding wire as my discharge draw on the 48v banks will not exceed 200 amps, allowing plenty of leeway.further I’m cutting 3/8” copper pipe and making my own terminals using the hydraulic crimp. When calculating busbars, each one rating to it’s combined total discharge amps for your system.
21:50 "... who is the idiot that did this... "
EXACTLY!
Kudos to your camera operator, what's the name of the carbon conductive compound. Is it necessary for the temperature leads that you tapped off of the bus bars? Nice catch on the difference in resistance between copper and brass.
The paste is mg847. I don’t use it on the sensing leads but that’s a great question.
The wires that transport electricity betwen houses is alternative ... So... Is capable of more power. But if you use dc on them, you will loose a lot of power. Bigest the wire lenth, biggest the looses.😉 About those brass brackets... Are good for less power...for other projects...etc. you don't need to thow them.
There is a anti corrosion spray you can apply when your all done.
Jello. Thanks for all the videos. I’ve seen 7 in the night! Could you give us some information please about the paste name for exemple you use? And perhaps some drawings regarding the boxes? It would be helpful? Last thing. Are you really think pressure will keep the battery well? How many PSI pressure?
Thanks for watching. All the info you are asking is in the videos. I hope you can see them all. The short answers are, the paste is MG847, The box dimensions are 18x31.75x11.75 inches. I restrain the movement of the batteries with minimal pressure. The nuts are installed at 1.5nm when the cells are at a fairly high SOC. I discuss these things in detail. Good luck with your project!
Thank you for this video, just about to build a 32kWh Lifepo4 battery to add to my other 32kWh battery. Some things I missed like double crimping and heat shrnk. What are your thoughts on double bus bars on each connection?
I have other videos in a playlist that shows all of my preferred methods. Good luck with your project.
Oxygen free copper as used in sound systems may be of use in lower current situations.
so much cool stuff here. I noted the copper bus bar was not flat and wonder why you did not heat up to recrystallice and make the relatively hard rolled copper soft so it can better form after the terminal ?
Way too time consuming.
Great video man.... What kind of shampoo do you use?
That is a funny question. I've had really short hair for many years. I grew it out to honor a friend that died and now my wife loves it. I prefer it short but it means more to her so I'll keep it for awhile. Head and shoulders and coconut conditioner. hehehe
Crimping, correctly, causes a cold well!! Superior to soldering!
Great video, could you still use those brass buss bars but double stack them to double the cross section and halve the resistance?
You could use them any place where 4 gauge wire is appropriate I suppose. You could double stack them but they really aren't very flat even after I flatten them so contact area is hit or miss and I would think it would be chasing performance in the wrong way. I think they are fine for top balancing and low amp situations but......
The real issue I have with these bus bars and with cabling that is too small is the resistance and what it does to the BMS as it tries to read your cells and balance them. Have you had a chance to watch my video on that subject? It's titled "It's no joke, size really does matter"
I made my own busbars out of 4 x 20 mm copper bar - I cut them with large bolt cutters - I hold them down with bell washers and nyloc nuts - - for my ev conversion - no fire yet
Have they started to tarnish?
SOLID
Since these cells expand and contract with SOC, I decided it was worth paying for the laminated/flexible bus bars, rather than using the solid bars that shipped with the cells.
I understand. I chose to restrain the movement instead and use the solid busbars. I'm only using 7 inch lbs of force on the nuts at 50% charge. When fully charged, they don't measure even two inch lbs more. It is actually hard to tell a difference in the pressure so I don't think they are going to be an issue. None of the battery pack manufacturers that I have seen use flexible bus bars. Most use long bus bars that are spot welded and the cells are not restrained with any real system that measures the force. It is an ongoing discussion that isn't settled but solid bus bars do not appear to be causing problems beyond theoretical. Poor connections seem to be at the root of the issues that happen. That and some isolated instances of very poor judgement.
@@RayBuildsCoolStuff would creating an oval hole be better to allow a bit more wiggle room for the terminals if using long busbars?
@@asderven the bus bars have oval holes in them but it is only for the variation in the cell sizes for the initial install. Once the terminal nuts are torqued to 5nm there won’t be any sliding on the terminal and if you leave them loose enough to slide in the oval holes it will be a problem electrically. So I’m still left with needing to restrain the movement of the cells.
@@RayBuildsCoolStuff Got it, thanks I see what you mean.
@@RayBuildsCoolStuff FYI, battery builder BYD uses layers of aluminum laminated into a flexible bussbar in their LFB batteries.
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