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.
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 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.
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.
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.
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).
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.
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
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.
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.
I love the video. I just found the channel. I'm building some small lithium stuff for car audio, but as a professional mostly commercial plumber who takes pride in their work I feel the same way about my work. So many good values shared in this video when it comes to approaching any work. I'll be watching more, and learning.
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.
I'm glad that people like you and the majority of RUclips CCs are trying to make it clear why solder joints are not a good long-term means of carrying the amperage that the conductor is capable of.
This really is a bit of a master-class. Definitely puts emphasis on certain aspects of connections. I.e the importance of the heatshrink with the adhesive I figured was only important on marine applications. I'll be spending the money on heatshrink regardless of application next time.
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.
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.
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...
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.
My projects just took a turn for the better. Thank you for sharing your wisdom. So many of these build videos on RUclips are lacking the basic analysis you have done. I am a new sub.
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.
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.
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!
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..
Thanks for a great video. I am a little concerned about how to connect batteries to bus bars using cables. Eg. I am using 2/0 welding cables with tin coated ring type crimp terminals to go between the batteries and bus bar and the same type of cables and terminals to go between the bus bars, fuses, and switches. I am using Victron 600A bus bars, Three Renogy 12V 200Ah LiFePo4 batteries connected in parallel. It seems like I should make the connections as short as possible and as simple as possible. Could you give suggestions on the conductive paste and anti-oxidant you use. When looking, I saw a MG Chemicals 847 carbon conductive assembly paste. Would that be okay? Should the paste go on every connection? What milliohm meter do you use and do we need one? Thanks again.
1.3mOhm * 200 Amps = 0.26V drop. 0.26V drop * 200 Amps = 52 watts of heat! Copper has an air transfer coefficient of around 14W/(m^2K). The bus bar has a total surface area of around 0.005 sqr meters. Works out to roughtly a 60*C bus bar in 20*C air. Or I messed up teh maths somewhere.
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.
hmm something you didnt talk about which is important with DC over a few volts is galvanic corrosion, especially on the + terminal side, which is sped up by orders of magnitude by the joining of 2 different metals. Ive always wondered about sacrificial anodes, not for marine use but just regular air use. you can make a bunch of pretty much pure zinc disks by putting pennies into a disposable cup and adding 2% OTC hydrogen peroxide and white vinegar and stirring. dont drink the bahja blast that results, and they should be newer post 1988 or whatever pennies. in my enclosed battery/supercap thing im building in a somewhat airtight "ammo can" build, I was going to put some at the bottom for thermal mass and just to preferentially take the oxygen out of the air and lower the level. add some desiccant packs too to keep an eye on things. this isnt really a true use of a galvanic sacrificial anode but it is how i would make some for basically free. maybe ill look for some nooks and crannies in my car's frame to stuff some extra ones in. most modern anti rust coatings are pretty good now days... but the mild steel used for car mfg is the absolute lowest quality in terms of anti-rust ingredients like chromium and they are really making the paint/finish do all the work... an example is basically every car battery in N america. look at the wires connecting the + terminal vs the negative, the + terminal is always significantly more rusted....
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 RUclips 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.
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.
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.
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.
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.
no no no no you want solid connections you go old school old school solder 60 40 none of that new crap you heat that thing with a torch you solder all connections then marine heat seal the ends with glue heat shrink... the bond between high power cable and the connector is not full when you solder its got less resistance etc.. just watch some of the old nasa videos and old 50s videos on how to solder this is the proper way to do it and use old solder not this new crap... and never lead free
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.
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.
What about putting a battery bank into a very rigid frame (now we have a carbon that is stiff enough and is light) and apply a good compression (which is always good disregarding of an environment) to shake it as a one piece?
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.
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).
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.
If your soldered joint gets hot and melts you have much bigger issues! Soldering a lug on is perfectly fine if done correctly. Never solder the end of a cable and attach it in a screw terminal. It will fail simply due to weather/temp cycle.
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.
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 😊
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 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.
Hi Ray. Thanks for your videos. I have a question about applying thermal grease. I have been using it between my lugs and my busbars and my lugs and my battery connections. My batteries are server rack type. The torque is 8 NM. The grease came with a little paddle for applying. I smear a thin coat on the bottom of the lugs. I notice on some connections that some grease has squeezed out. Am I putting too much on? Could this hurt conductivity?
I think it takes very very little. I see it as similar to lubricating o rings. The film required isn’t much. As for my opinion about it hurting conductivity? I’m all about testing. Also, you said you use thermal grease. That is a different type of product. I have used it in the past for mounting parts onto heat sinks. I would read the technical data sheets for the product that you are considering using. Try to find the papers that are written by the chemist. Usually those are the instructions. If there is a hint of marketing, don’t count on it.
Thanks Ray. Big screwup on my part. I thought I was using the same stuff you were recommending only at half the price. Glad I reached out to you. The stuff I got is for thermal conductivity not electrical. Also has high carbon content. Improving electrical conductivity by up to 30% is what hooked me (your video). I will be cleaning my connections and redoing them with the MG847.
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?
Great info... except this seems odd... In comparing the bus bar with the cable - "depends on how far apart. Because the further apart I get them [meter probes] the more resistance. Yet the distance of the probes from one another on the cable when you measured was more than twice the distance! ruclips.net/video/ZzKR6tYRlwM/видео.html
Yes that’s true and the way I presented it may be confusing but if you watch that whole section again with the part that follows it is clearer. I also have another video about flexible busbars that compares different wire gauges to solid busbars with resistance values and their length factors.
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!
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 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!
Who is the idiot who did this? Aiming at perfection, it is also my motto. Don't use other people's criteria, but your own. When you're satisfied, it can't be built better. And even then you will find some things made by you in the past that need improving, yes, because you learn too. Love your stories and your work, keep on doing the good work, but do not let RUclips lead your channel to go awry.
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
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."
I haven’t got time to read all the other comments, so forgive me if someone else has mentioned this, but, when you were doing your test between a solid busbar and flexible, you showed the difference in resistance, as being much greater in the flexible. I did notice that the length of your wire was, at least, twice as long, maybe even 2.5 times longer, so wouldn’t that create more resistance anyway?
Of course. This video is focused on making good and safe connections while I have another video about solid and flexible busbars which explores cross sections and length and the requirements for resistance equivalency.
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.
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.
@@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.
How about taking old wire with oxidation and cleaning the end perfectly, like new, then putting a terminal on it? The flow of electrons doesn't about oxidation does it?
I don’t know the answer to that question. I am aware that electrons don’t flow through a wire but around the wire but I don’t know how that may or may not be significant. The accurate answer is that I don’t know.
Which resistance tester do you use Ray? And what is the primary difference between that and a normal Fluke meter? I noticed yours has 4 wires for measuring…
I use a YR 1035+. It has 4 wires because it sends a small amount of voltage on two of the wires and tests resistance to 4 decimal places. The fluke can't come close to that sensitivity or accuracy.
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.
😂
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 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?
I was really impressed to see what actually a "gas tight joint" is.
Thanks a lot!
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.
Great content, recently upgraded my tools as a result of a electrical position with Earthroamer. Quality tools for life.
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
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.
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.
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.
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.
21:50 "... who is the idiot that did this... "
EXACTLY!
Crimping, correctly, causes a cold well!! Superior to soldering!
I love the video. I just found the channel. I'm building some small lithium stuff for car audio, but as a professional mostly commercial plumber who takes pride in their work I feel the same way about my work. So many good values shared in this video when it comes to approaching any work. I'll be watching more, and learning.
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.
I love those drill bits with threaded inner. Nice routing for the busbars.
I'm glad that people like you and the majority of RUclips CCs are trying to make it clear why solder joints are not a good long-term means of carrying the amperage that the conductor is capable of.
This really is a bit of a master-class. Definitely puts emphasis on certain aspects of connections. I.e the importance of the heatshrink with the adhesive I figured was only important on marine applications. I'll be spending the money on heatshrink regardless of application next time.
Thanks for pointing out how big a difference there is between copper and brass. Wow! I'll be checking what they send me.
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.
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.
Those cables are twice as long as the bus bars. No surprise you get nearly twice as much resistance.
Thx. I use 1/0 welding cable minimum.
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...
That's the work of a perfectionist ! I like it ...
The tip on attaching the balance leads mid point on busbars so they don’t interfere with torquing the bolts is very good. Thanks!!!
Great video, Ray! I always taught it's all about means, methods, and materials... and you will always have quality results!
what a wonderful video - you're great bro. thank you :D
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.
My projects just took a turn for the better. Thank you for sharing your wisdom. So many of these build videos on RUclips are lacking the basic analysis you have done. I am a new sub.
thank you
SOLID
I think I just found my latest favorite channel!
You made me smile.
👍👍
Very good presentation. What kind of milli-ohm meter do you use, and what should I expect to pay for one? Thanks!
I use a yr1035+ they cost 50-70$ depending on shipping and such
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.
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.
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!
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..
Thanks for a great video. I am a little concerned about how to connect batteries to bus bars using cables. Eg. I am using 2/0 welding cables with tin coated ring type crimp terminals to go between the batteries and bus bar and the same type of cables and terminals to go between the bus bars, fuses, and switches. I am using Victron 600A bus bars, Three Renogy 12V 200Ah LiFePo4 batteries connected in parallel. It seems like I should make the connections as short as possible and as simple as possible. Could you give suggestions on the conductive paste and anti-oxidant you use. When looking, I saw a MG Chemicals 847 carbon conductive assembly paste. Would that be okay? Should the paste go on every connection? What milliohm meter do you use and do we need one? Thanks again.
The 847 is the paste that I use. I use it on almost everything. I do use a good milliohm meter. I can recommend the YR1035+.
@@RayBuildsCoolStuff Thank you.
1.3mOhm * 200 Amps = 0.26V drop. 0.26V drop * 200 Amps = 52 watts of heat! Copper has an air transfer coefficient of around 14W/(m^2K). The bus bar has a total surface area of around 0.005 sqr meters. Works out to roughtly a 60*C bus bar in 20*C air. Or I messed up teh maths somewhere.
Could you comment on 100% bare copper bus bars
vs
chromed or zinc plated or "marine grade" copper bus bars ?
COOP
...
much food for thought...............thank you!
This is entire video is filled with great advice...thank you.
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.
For sure it is a Fire risk.. unsolid connections cause plasma sparks.. FOR REAL.. very good topic … SOLID connections .. life story ;)
After watching about a dozen of your videos I have about 3 million questions but I also have a shoe string budget
hmm something you didnt talk about which is important with DC over a few volts is galvanic corrosion, especially on the + terminal side, which is sped up by orders of magnitude by the joining of 2 different metals. Ive always wondered about sacrificial anodes, not for marine use but just regular air use. you can make a bunch of pretty much pure zinc disks by putting pennies into a disposable cup and adding 2% OTC hydrogen peroxide and white vinegar and stirring. dont drink the bahja blast that results, and they should be newer post 1988 or whatever pennies.
in my enclosed battery/supercap thing im building in a somewhat airtight "ammo can" build, I was going to put some at the bottom for thermal mass and just to preferentially take the oxygen out of the air and lower the level. add some desiccant packs too to keep an eye on things. this isnt really a true use of a galvanic sacrificial anode but it is how i would make some for basically free. maybe ill look for some nooks and crannies in my car's frame to stuff some extra ones in. most modern anti rust coatings are pretty good now days... but the mild steel used for car mfg is the absolute lowest quality in terms of anti-rust ingredients like chromium and they are really making the paint/finish do all the work...
an example is basically every car battery in N america. look at the wires connecting the + terminal vs the negative, the + terminal is always significantly more rusted....
Aim at equanimity then perfectly executed practices are possible!
Obviously you are a man I should share time on the porch with.
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 RUclips 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.
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.
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.
Why not use silver instead of copper sense it has 100% conductivity
👍🤗 Gut Video
Oxygen free copper as used in sound systems may be of use in lower current situations.
Incredibly useful information - thank you
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.
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.
Solid advice here. Worth the time spent to watch in full. Thanks for posting
Jack Richard who built electric cars ended up using mesh connectors to prevent vibration loosening between batteries.
no no no no you want solid connections you go old school old school solder 60 40 none of that new crap you heat that thing with a torch you solder all connections then marine heat seal the ends with glue heat shrink... the bond between high power cable and the connector is not full when you solder its got less resistance etc.. just watch some of the old nasa videos and old 50s videos on how to solder this is the proper way to do it and use old solder not this new crap... and never lead free
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 use a corrosion prevention treatment on my equipment, KC2-AGT Thanks
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.
What about putting a battery bank into a very rigid frame (now we have a carbon that is stiff enough and is light) and apply a good compression (which is always good disregarding of an environment) to shake it as a one piece?
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.
Subscribed! Wonderful content and a one of kind teacher!
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).
Good video, I have not seen anyone talk about connections as you have, Thank you very much.
The un insulated transmission wire is not bare for thermal dissipation. The heat is low because of the higher voltages. Most lines are rated at
The lines I’m speaking of are neighborhood scale distribution lines and the information comes from a short class I took on power distribution.
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.
Excellent video and information. Many thanks.
If you're not strong, you gotta be smart
If your soldered joint gets hot and melts you have much bigger issues! Soldering a lug on is perfectly fine if done correctly. Never solder the end of a cable and attach it in a screw terminal. It will fail simply due to weather/temp cycle.
@@ursodermatt8809
Agreed. It’s been proven on the larger lugs a crimp is far superior.
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.
6:58 on the few best advice you ever get in your life
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 😊
Ray, thank you very much. Bless you and your family.
There is a anti corrosion spray you can apply when your all done.
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...
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.
I love this attitude and the awareness with concern of details.
I like your attention to detail
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.
Hi Ray. Thanks for your videos. I have a question about applying thermal grease. I have been using it between my lugs and my busbars and my lugs and my battery connections. My batteries are server rack type. The torque is 8 NM. The grease came with a little paddle for applying. I smear a thin coat on the bottom of the lugs. I notice on some connections that some grease has squeezed out. Am I putting too much on? Could this hurt conductivity?
I think it takes very very little. I see it as similar to lubricating o rings. The film required isn’t much. As for my opinion about it hurting conductivity? I’m all about testing. Also, you said you use thermal grease. That is a different type of product. I have used it in the past for mounting parts onto heat sinks. I would read the technical data sheets for the product that you are considering using. Try to find the papers that are written by the chemist. Usually those are the instructions. If there is a hint of marketing, don’t count on it.
Thanks Ray. Big screwup on my part. I thought I was using the same stuff you were recommending only at half the price. Glad I reached out to you. The stuff I got is for thermal conductivity not electrical. Also has high carbon content. Improving electrical conductivity by up to 30% is what hooked me (your video). I will be cleaning my connections and redoing them with the MG847.
Thermal grease meant for computer CPU heatsinks is normally electrically insulating ...
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.
Great info... except this seems odd...
In comparing the bus bar with the cable - "depends on how far apart. Because the further apart I get them [meter probes] the more resistance. Yet the distance of the probes from one another on the cable when you measured was more than twice the distance! ruclips.net/video/ZzKR6tYRlwM/видео.html
Yes that’s true and the way I presented it may be confusing but if you watch that whole section again with the part that follows it is clearer. I also have another video about flexible busbars that compares different wire gauges to solid busbars with resistance values and their length factors.
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!
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.
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.
Who is the idiot who did this?
Aiming at perfection, it is also my motto.
Don't use other people's criteria, but your own.
When you're satisfied, it can't be built better.
And even then you will find some things made by you in the past that need improving, yes, because you learn too.
Love your stories and your work, keep on doing the good work, but do not let RUclips lead your channel to go awry.
I don't understand what you mean about youtube leading the channel awry and "who is the idiot who did this?" What am I missing?
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?
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 think I’m going to like this channel.
I haven’t got time to read all the other comments, so forgive me if someone else has mentioned this, but, when you were doing your test between a solid busbar and flexible, you showed the difference in resistance, as being much greater in the flexible. I did notice that the length of your wire was, at least, twice as long, maybe even 2.5 times longer, so wouldn’t that create more resistance anyway?
Of course. This video is focused on making good and safe connections while I have another video about solid and flexible busbars which explores cross sections and length and the requirements for resistance equivalency.
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.
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.
How about taking old wire with oxidation and cleaning the end perfectly, like new, then putting a terminal on it? The flow of electrons doesn't about oxidation does it?
I don’t know the answer to that question. I am aware that electrons don’t flow through a wire but around the wire but I don’t know how that may or may not be significant. The accurate answer is that I don’t know.
Shouldn't go in the trash. Someone might want some brass on eBay
They are ok for top balancing.
Do you feel crimping is better than soldering?
Sorry Ray, I got ahead of the video. No need to answer.
Which resistance tester do you use Ray? And what is the primary difference between that and a normal Fluke meter? I noticed yours has 4 wires for measuring…
I use a YR 1035+. It has 4 wires because it sends a small amount of voltage on two of the wires and tests resistance to 4 decimal places. The fluke can't come close to that sensitivity or accuracy.