All these different busbars... and why they don't matter!

This is a test I wanted to do for some time. Testing out different busbars and see how they perform, how the resistance is what the best choice for my battery is. Can they actually cope with 160A and how hot do they get?
I also promised Madi to test her busbars she sent over a while back, so...
On the testbench we have:
- the EVE standard tinned copper busbar coming with the cells
- Power Paul's aluminium busbar
- 2 of Madi's self made 'flexible' busbars
- a tinned copper flexible busbar from AliExpress
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[@dennis_m]

Thank you Andy, the Neeeeeeey has been working great. It has balanced my cells very well. And I did arrange the balance cables with zip ties haha, looked messy in the picture, was so excited to send the pic ASAP! Andy included a hand written letter, lovely and I'm touched. Thanks so much!!!!

[@jackiedines5229]

Seems I am not the only one to get caught with AliExpress junk batteries, oh well good luck and I hope you get somewhere near your moneys worth.

[@OffGridGarageAustralia]

Thanks Dennis. Great to have you on board and I could help to make your battery a bit better.

[@tanishqbhaiji103]

Dennis, look for MDS enterprise in Imphal, have have good EVE LF105s.

[@upnorthandpersonal]

Thanks for the shout out, Andy! Yes, I know, a blog... ;) I'm just not very good at putting things in video format, or being in front of a camera. Edit: and yes, the balance leads are organized, that picture was work in progress :)

[@largepimping]

I'd like to add that Up North and Personal is also very helpful in youtube comments. Both answering questions as well as trying to correct misinformation from a very small number of other commenters.

[@Dirt-Diggler]

Do as i do, stay behind the camera 😁 I'm sure you have something to add to the community judging by your posts on here 😎👍

[@CollinBaillie]

I think a blog is excellent value! Andy was making a joke, I think. Also, blogs being text, are much easier for search engines to index, so your likely to have more people find you, so long as they're using a search engine, not youtube to perform the search. 😆

[@upnorthandpersonal]

@@Dirt-Diggler I do have some videos on my channel where I do that. I'll see if I can expand on that.

[@petsonly4068]

Appreciate your effort on documenting the entire thing

[@TheDigitalMermaid]

Thank you very very much for this! After our chat, I was worried that the flexible might have been two small. This is a wonderful result and makes me feel a lot better. The Anderson connector I am using is rated to 175A, so your test is nearly maximum load. Just wonderful! ^_^

[@joesrvhome]

Great job on those bus bars! :)

[@OffGridGarageAustralia]

Yes, I can only say, congratulations on these bus bars and design. The quality seems to be perfect. Just don't put a washer underneath ;)

[@fixitralphltd4988]

Soon as I saw you even torque the bolts, I knew you wasn't messing around, you're hard core testing this

[@damianhla]

Excellent review Andy. Busbar temperature and poor contact surface area heating are surely one of main concern areas that needs to be monitored. Very interesting results indeed. My experience is similar to your test results. The Aliexpress Flexible busbars also came out #1 as depending on the dimension, they come in 300A and 400A high current versions. You can actually get suppliers to make custom lengths as well, besides having a wide range to select from. The #2 is tin plated copper bars. Copper has a lot less internal resistance than Aluminium. Aluminium only has 61% conductivity of copper, so much thicker conductor must be used. The main issue with copper is that it can form oxide and this oxide does not conduct well. Issue is addressed if it is tin or chrome plated. 😊👍 If you get slightly longer Aliexpress flexible busbars then bend and incorporate a small U-shape profile, this would allow the busbar to flex length-wise as well. This is how i got them to fit in my setup 😉👌

[@camielkotte]

Still waiting for my 8 280 cells , but i have learned so much on your channel. Thanx a million amps!

[@FloTheBestEver]

Hi Andy, a tip for thermal imaging: on a shiny and/or metal surface you need a layer with a known or near 1 emission factor as the emission factors of the materials above are nearly unpredictable. I use a bit of black electrical tape for that puspose.

[@davidpenfold]

I'm impressed by the original tin and copper busbars.

[@edwardvanhazendonk]

Great test, I think for a moving boat the flexible busbars make sense. But indeed measuring every connection for resistance and oxidation makes sense. Thanks Andy!

[@OffGridGarageAustralia]

That's where the Flir camera comes into play. Very easy to see where the problem is...

[@lastfeatheroffreedom9665]

Aluminum is famous for heating up and remaining hot , I work with it daily even deburring on a soft wheel will get that type of metal super hot . I'd go with a good copper busbar everytime. Great video , I really appreciate it helped me think of a couple new ideas for me to tryout myself.

[@1956vern]

Thank you! Really enjoyed your experiment with busbars!

[@User1462uuw8w]

Hi, everyone) Thank You Andy! I have chosen flexible busburs after watching this video! And I have got perfect connection with them with sanding and cleaning with alcohol. No worming up and low resistance (don't remember, maybe 0,002 mOms) My 8cell battery have 1,150 mOm resistance on terminals and nearly 2,120 mOms on negative terminal connection after 200A Chint DC braker and GBat 200 A DC melted fuse and after bms on positive. Looks very effective and durable.

[@solargarage]

Nice results, thanks Andy.

[@Juergen_Miessmer]

Thank you Andy. What a result. Simply using the original that came with the cells is the best choice. ;-)

[@OffGridGarageAustralia]

Yeah, I'm only using the ones coming with the cells now and it all works fine.

[@Ryan-hn3vd]

Perfect timing!! I was going to make some fancy aluminum bus bars from stock, but now I will just use the ones that came will the EVE 304 cells

[@chevrofreak]

I have a 16s pack with the EVE 304ah cells and the busbars don't even get warm to the touch during normal usage, which is minimal current as my entire battery bank is 36kWh.

[@williamhustonrn6160]

Just check yours after you install them for hot spots, mine came with busbars, but they were not going to work in my setup (96v battery bank) so i made my own from 1/2" copper tube i flattened in bench vise and i had absolutely no hot spots since the copper tube moulded when i torqued the copper nut since i used copper studs and copper nuts. I went the copper route, because i read somewhere that the LiFePO4 cells were copper with nickel coating on the terminals.

[@pilgrimvalle]

@@williamhustonrn6160 terminals are made of aluminum....copper is a far superior conductor for busbars. or copper cables...

[@babaluto]

@@williamhustonrn6160 That is what I have used in the past. What wall thickness are you using? K, L or M

[@kenmorcom5554]

Thank you for your test and video. After thinking about this for a while, I think the solid busbars are problematic. They rely on the battery terminals being in exactly the same plane. If there is any twist the solid busbars will have to bend to compensate. The Aluminum busbar would have the greatest problem in this area as it has to be thicker to maintain the same conductivity as copper. (this may be why the aluminum terminals had the greatest connectivity problems.) I like the braided busbar as it generates the least stress on the battery terminal. Cheers, Ken

[@kswis]

That is very interesting. Thankyou for the in-depth test.

[@OffGridGarageAustralia]

Thank you.

[@billxam2674]

Andy, I have totally switched everything to shrink tubing and zip ties for looms, connections and everything else. No more tape or wire messes for me!

[@robertkosovich1232]

Andy just 6:30 into the piece, these videos keep getting better and better, keep em coming, Enjoyment and Learning! ........ S.P.A.T. to ya!

[@Toasta-Builds]

I got sucked into the whole (make your own better busbars) but I’ve never had a problem with the bb that come with the cells… work great straight out of the packet

[@OffGridGarageAustralia]

I'll use them for the new batteries going into the shelf soon as well.

[@excillisbank2611]

Merci Andy pour encore une fois une belle démonstration technique. Bonne continuation.

[@OffGridGarageAustralia]

Merci beaucoup!

[@mihaitaiosub]

Hello Andy,I want to share my experience with busbars,after an year using my battery bank. A few days ago I also completed 30 busbars for my 32 cells and 600 amp battery bank.I approached the problem from the point of view of corrosion that can occur at the aluminum terminals of the cells.I used a 35 mmp conductor and at the ends I used ring terminals made by me from 2 mm thick sheet, the sheet which has one surface of aluminum and the other surface of copper.I soldered the 35 mmp copper conductor to the copper surface of the terminals.Thereby it will come into contact with the cell terminals only the aluminum surface of the terminals.Thus, at a length of 18 cm, we obtained a resistance of 0.15-0.16 mohms. Before this setup, I used the same type of cable, the same length, but at the ends I used copper ring terminals soldered.I was fine for almost a year, but after a year some problems appeared due to the oxide that appeared between the aluminum terminals of the cells and the copper ring terminals. I opted for the version with flexible busbars because the placement of the cells requires it and because the cells are fixed in a frame with 300 Kgf.

[@dig1035]

Absolutely fascinating, thank you!

[@pilgrimvalle]

there is a youtube guy "ray builds cool stuff" who tests the resistance via different methods of connecting the nickel plated copper busbars to his EVE 280Ah cells.... he (Ray) also noted one vendor sent him tinned brass busbars which increased the resistance a lot.....copper is the best choice and the thicker it is the higher its ampacity will be and the corresponding resistance... I recommend tinned copper bus bars and pure copper cables with tinned lugs that have adhesive shrink wrap at the lug/cable junction to limit oxidation... avoid brass bus bars...have a great day all....cheers from the off-grid farm in South Dakota.....USA

[@OffGridGarageAustralia]

Thanks Michael. The aluminium busbars have actually a lower resistance than the standard copper ones coming with the cells. But obviously they have their problems with with oxidation and high resistance to the busbar if untreated. I agree, copper is definitely the way to go. Madi has actually used these adhesive heat shrink with her cables she made. I can see the clear glue coming out a bit where the heat shrink ends.

[@gannas42]

Thanks for the video! I In my experience aluminum is not a desirable conductor so your results make sense to me. 👍

[@OffGridGarageAustralia]

Thank you! As with previous tests I did, the aluminium busbars are a better conductor as the copper busbars due to the fact they have larger dimensions as the standard copper busbars. But the contact areas are a real problem. Tinned copper is definitely better.

[@Mr.J345]

I think bending the flexible bus bar loosened the braid which shortened the length. I’m curious if it would have fit beforehand. Try putting a screwdriver through each hole and pull to try to lengthen it.

[@TheDigitalMermaid]

If you have to pull it that tight to connect it, is it really flexible anymore?

[@Mr.J345]

@@TheDigitalMermaid I’m saying stretch it back to its original length I’m thinking that’s it’s shorter than it’s factory center to center length because he was bending it back and forth and it didn’t appear to be missing the stud by much. And great video on the cerbo gx and display you explained exactly what I was confused about so I ordered one now lol

[@sreekumarUSA]

Do not try this. Because the braid ends may get , either detached or get lose , causing issues. Prepare a new one to exact measurement, instead.

[@berndtwagner189]

Thanks for this Video. Conclusion: High Power loves copper, even more tinned copper!

[@pilgrimvalle]

copper for sure is good,,,, the tinned part is to prevent the galvanic corrosion between different metals,,, the tin coating decreases the conductivity a little

[@OffGridGarageAustralia]

The aluminium works as well if the connection is good 😉

[@danfitzpatrick4112]

Very interesting Andy. I used solid copper for my bank, but almost went with aluminum. Glad I didn't now! Awesome test as always! Thank you

[@OffGridGarageAustralia]

Thanks Dan! 👍 Copper is the way to go, I think.

[@danfitzpatrick4112]

@@OffGridGarageAustralia I agree, and I think the idea with the #4 copper with lugs would be best with a small space between batteries. This would allow for any expansion and contraction so that there is no tension on the terminals as well. (Mermaid's dream cables)

[@chevrofreak]

If you use a lower wattage incandescent light bulb as a resistor, it will light up while the capacitors are charging and it will dim and go dark when they are full, which will prevent you from hooking up the cable prematurely.

[@sreekumarUSA]

Roger, The Power supply is 48~54V. The Incandescent filament will be obliterated, if Andy doesn’t have a 54V filament incandescent bulb, right? 22+22 Ohm (11 Ohm approx) @ 5W is good as shown.

[@chevrofreak]

@@sreekumarUSA I meant a 120v bulb. I use them regularly. Andy will have 230v bulbs, so lower wattage will be best for him.

[@westking7746]

I wondered about this. This is good to know. I imagine that using a bulb with a voltage/wattage rating a little higher than the system being charged would be key to not losing the bulb in the process as you all said.

[@chevrofreak]

@@westking7746 we used this trick with a 12v bulb to charge super capacitors in car audio systems back in the day. My 5 farad capacitor even came with a bulb to use. I added a light bulb fixture and 7.5W bulb to my system as a pre-charge resistor, and with my 12KW Growatt inverter it takes a solid 20 seconds for it to dim and go dark. I think something around 20W may be ideal.

[@westking7746]

@@chevrofreak LOL. OK. Yeah. I remember the light bulb with the capacitor deal. I never knew what they were for. My Dad usually installed stuff like that.

[@waynescheepers145]

Andy, great video as always. I know it's impossible to do it as you put so much effort Into the videos for our entertainment but wish there was more videos to watch back to back (without restarting from the beginning) My new born son is finally out of icu and home, Logan will fall asleep many times in his life hearing uncle Andy do his thing 😋😃 In a country where we have load shedding frequently (south Africa can't supply enough power due to lack of maintenance to power stations ) solar is the way to go.

[@kevinroberts781]

I made my bus bars out of 2/0 copper. It was welding cable.

[@alexschulein7002]

hi Andy. looks like those braided copper straps did very well. since you mentioned that they were a bit too short i started looking around and i think i found the seller on Allie you used, well if it is the same seller they offer custom length straps aswell if you order 100 or more. maybe if there is enough demand from the community you could resell them. the biggest advantage using these straps is that they conform to their mounting, if one batt is higher it can move to accommodate the position. there is a reason heavy industry uses these kinds of bonding straps.

[@upnorthandpersonal]

I use them on my battery, but I make them myself. It's time consuming, but they've been running for two years now without issues.

[@ForbiddTV]

@@upnorthandpersonal You ought to make a video of how to make them, I think many would be interested.

[@tiloalo]

And I guess by pulling a little on them they would still extend by a mm or so. They don't look fully extended in the video

[@upnorthandpersonal]

@@ForbiddTV I'll give it a try. I have to make a set anyway this spring/summer.

[@damianhla4940]

Very well said Andy. LFP is indeed very different than Li-ion when it comes to applying an appropriate charging strategy to prolong the battery life. I have been running full off grid solar now for past 8 months, relying on 16x SUNPOWER MAXEON-3 400W panels and 6x VICTRON 50/100 Smartsolar controllers connected to BMS and CERBO GX to manage the whole setup. For battery I am running 12x 120Ah LFP from ITECH. The main challenge is in winter trying to recoup full charge on limited hours of productive sunlight and poor rainy weather. Often there is only around 3 hours of good sun in winter to charge at higher current >150A. It is great that LFP can take in much higher charge current than Lead Acid batteries. I utilise DVCC on CERBO GX to set upper limit of 250A for charging current and 14.5v on charging voltage as well to protect the system. With 1440Ah battery capacity 250A is only 0.17C, which is well below the 1C LFP is capable of. Happy to report that with some tweaking on the solar panel placement, this setup has been working extremely well and managed to deal with consecutive poor weather days with lots of reserve left. The POC Poof-Of-Concept phase has indeed completed successfully in proving if it is possible to go 100% off grid solar with current battery and solar technology. I have since contacted Synergy the power company to disconnect my power and finalise my account. Keep up with the good work. Are you planning to scale up your solar system to start parallel run on semi-of grid setup?

[@OffGridGarageAustralia]

Thanks a lot for sharing. That is very interesting and great to hear. I think it depends where you are on this planet to make it work and how much power you consume. I am currently upgrading my solar on the garage and have also looked around for other suitable locations especially during winter time to get more energy. With an EV, pool and electric hotwater, I need lots.

[@EMCProton]

Good job on the presentation. I believe that I make an idea as to why your connectors on the hookup wire are a bit hot. When making a bench spot welder, I had a problem with my cable getting hotter than the welding point. We found that the connectors cross section area were smaller than the welding point. We made the connectors thicker. When we did this, the temperature at the connectors was much lower and the welding point started welding properly. Think about the wire size for your current flow. The wire and connectors are resistors in the circuit. Smaller (cross sectional area of the wire) wire, in this case, smaller connectors bigger resistor. I find that many do not take the connector size into account when building a circuit. I hope this helps. Fairwinds and following seas.

[@geraldhenrickson7472]

Nice to know. I charge at 30 amps and discharge at 50 max so i will just use the bus bars that came with my LF304 cells. Thanks OGG!

[@OffGridGarageAustralia]

Yes, use the bars coming with the cells, they will be totally fine.

[@5fxindices933]

You understand, I presume, that your R, ΔV measurements are flawed, as they deviate from Ohm's law and test conditions. The series current is the same on all 5 jumpers, hence if you view them like shunts, the I = ΔV/R should have been the same, within meter's accuracy and rounding errors. They are in fact: 6.00, 14.12, 8.75, 8.50 and 6.25 Amps, very distant from the 160 Amps that were flawing during your test. Greetings from sunny Greece. Nikos

[@OffGridGarageAustralia]

Yes, I know that but just presenting the overall verdict, that not the material is the problem but the resistance.

[@westking7746]

I remember that GMC pickups from the 1940s, 1950s, and 1960s with both 6- and 12-volt systems quite often used the braided straps as ground straps between the body and the frame. Braided straps were also used between the battery and either the engine or a point on the frame. The only downside that I could see was that they were corrosion prone at the lead-acid battery negative terminals. The old 6-volt systems had positive battery cables as thick as a grown man's thumb, but I can't remember what the gauge was. My Dad used to make replacements for the corroded ground straps from scratch with a special crimper and terminal ends and soldered the terminal ends as insurance. The positive battery cable ends were replaced with a clamp on terminal end after cutting the corroded one off and stripping the insulation. They seemed to work OK at best. Those old battery systems were never that reliable even when new, especially the 6-volt outfits.

[@thomaslind1033]

The original Buzzbar is a god choise tinned Cooper works well together Whit Alu but it should be oxide free and vhit paste

[@SkypowerwithKarl]

Hi Andy Keep in mind that the battery terminal tops also form an oxide and should be removed as well. A twisting motion and scotch bright under your thumb for a few seconds is all it takes and won’t distort the flatness detrimentally. Use a can of dust off to blow out the holes because you don’t want grit in there. I made a lapping tool that works great and fast for terminals that already have studs(I made a video).Wipe off the top with alcohol and put on your favorite anti oxidant compound within a few minutes. Preparing both contact surfaces makes a huge difference. The flexible braided buss is very good but there’s things you need to know. It is perhaps a bit short but it can be lengthened by squeezing it’s width in the middle with your fingers. The problem with those is they need periodic re torquing as the stands within the ferrule compress. This will eventually settle down or an embossing tool can be made that can pre compress (in a machine vice) and flatten the contact area. Interesting resistance readings you got.

[@babaluto]

From my lead acid days, I use a facing tool that slips over the threaded post that takes any slight crowns off of the post.

[@SkypowerwithKarl]

@@babaluto I turned a blank perfectly flat and drilled a 6mm hole in it. The other end was drilled and taped 1/4-20 where I Loctite-d a socket head screw. I cut the “L” off a ball hex wrench so I could put it in a drill motor. The ball drill reduces any leaning and helps keep it flat on the terminal. I used a sheet of 400 wet&dry sand paper that I put thin double sided tape, cut to 1” squares and punched holes. Use a 6mm pin in the lapping tool to line up the sand paper. Low, low speed, light pressure about three rotations then a about one rotation in the one direction to release the fines in the paper so it doesn’t load up. The terminals must be absolutely free of oil or any oxide compound so I clean them before and after with alcohol. Any contamination will instantly load the paper in spots halting all progress. Soon after it’s lapped,use a very thin layer of an anti oxidant paste (Noalox) on the finished surface. Avoid getting the paste on the threads because it can increase the tension of the fastener when torquing.

[@babaluto]

@@SkypowerwithKarl Sounds very good. The tool I still have, I think I bought it from buggies unlimited, it is a hexagonal tool steel section with cutting edges milled into the facing side. A hole in the middle for the post. It fits nicely into a 7/8" socket for either an impact or drill driver. The cutting edges leave the surface super clean and flat. Haven't had any issues with it clogging or marring of the surface. I checked recently and Buggies doesn't list it any longer and I cannot find it anywhere else. I simply do not understand why someone would work so hard to make the bus bars so flat without checking the mating surface as well. Good stuff. Cheers!

[@OffGridGarageAustralia]

From what others said, the terminals are made from some different aluminium than the bus bars and don't oxide very much. In this test, I did not clean or treat the terminals at all. And the tinned copper bars are fine with this.

[@SkypowerwithKarl]

@@OffGridGarageAustralia I’m sure they are a different alloy than the buss bars. The important difference is they have been machined. The buss bars have what you discovered is a rolled finish that have a tough low conductive, oxide skin. All aluminum oxides but it’ll take quite a while in a nice environment to be as bad as the finish of the stock plate. The terminals are pretty soft yet weldable so I’d guess a 5XXX alloy. The buss bars are probably one of three 2024, 6061 or 7075 . Probably 6061 because it’s the most common and cheaper than the high strength 7075. Glad you figured out the hot bars.

[@philgavin]

You make a case for certainly using the convenience of the standard busbar for initial top balancing. Maybe the final build can be a more painstaking exercise, but if several banks are to be assembled, a set of the standard busbars is warranted for top balancing in the background during the build.

[@OffGridGarageAustralia]

Not sure if you have seen my previous videos but I have one battery bank already assembled with the aluminium bus bars for quite some time now (OK a few weeks only) and haven't had any issues after sanding and applying this paste to the contacts. The next two banks will be done with the standard bus bars coming with the cells, one bank will get the paste as well, the other won't. Just to see the difference over time.

[@OffGridBasement]

Great Video! I'm glad to see you really don't need to "upgrade" the busbars. I'm sure people need different types for different configurations, but for the most of us... Stick with standard copper!

[@TheDigitalMermaid]

To expand on what Andy said at the end; What is right depends entirely on each person's use and needs. For me, the effort to make the flexible was worth it because I'm using them in a high vibration, high shock loaded environment (on a boat, vibrations from a generator, and the crashing of waves). If your install is static, like Andy's, I think the bus bars that come with the batteries are just fine.

[@lloydwilson9104]

@@TheDigitalMermaid I think your design is a winner in an environment where movement is a possibility, your connections are much safer as there is far less exposed conductive parts improving safety, would be good to have covers over the studs as well like the type you get on car alternator terminals and i think it would be as safe as is possible, nice job

[@debperkins5212]

Hey Andy, my hubby faithfully watches your videos. He said to tell you that as a retired mechanic when he had a bad connection he would use an internal/external star lock washer between the contact surfaces for 100% connection. Worked every time. Might try that between battery terminals and bus bars. He thinks it just might work

[@OffGridGarageAustralia]

Hi Deb, thanks for your comment. That would be the worst connection for such high amperage. Imaging the star washer has only contact to either side where the stars are connecting to the metal surface. So all the current needs to go through these few connections points. This might be good for resistance but with amps going through it will heat up like crazy!

[@Falcon_Overland]

Agreed

[@jackiedines5229]

Those ally bars could do with some surface grinding! Fantastic test, it seems that heat or not tells you how good/ bad the bus bars are. If one does not have the camera. Thanks again for your effort.

[@OffGridGarageAustralia]

Thanks Jackie. The aluminium bars will definitely work but need some treatment, sanding and no-ox-id paste. I'm just not sure how long this treated connection will last.

[@aatdekwaast3968]

@Andy what i do not understand is the outcome of your second measurement, the internal resistant of the busbar at 160A. For example the first busbar did 1,2mOhm and 7,2 mV. That is not possible with 160A. The voltagedrop with 1,2 mOhm must be 160 x 1,2mOhm = 192milivolt. This value gives a wattage loss from 30,7 watt in that single busbar. :) I think the measurement of the internal resisant isn't right. What are your thoughts? I trust the voltage mesurement more than the internal resistant measurement. If we calculate the other way around than we get R=U/i = 7,2mV/160A=45 microOhm.

[@kevinmills5293]

things definitely don't add up.

[@CollinBaillie]

I'm pretty sure that the tester supplies an AC voltage at a particular frequency for the resistance test. Notice it has multiple prongs on each probe. There is a DC voltage test performed with one prong in each probe, and the resistance test is performed with the other prong(s) in each probe. It's not just a passive measurement, like a multimeter. Possibly one could conclude this makes it unsuitable for testing a bus bar, which clearly isn't a "chemical battery" and therefore isn't affected by that AC test, or the connected cell(s) are affecting the test, either way...

[@hommerdalor6301]

Yes, 30,72W, that’s why the batteries get hot after longer use, but the battery would run less than 2hours under that load. Cheers.

[@hmr_]

You are right, the figures are against physics. There is the ohms law U=R*I, which is violated by these figures. @Andy, please measure the voltage drop with your voltmeter, as well.

[@stevenlane729]

Hi Andy, another awesome experiment, Thank you. I think that it would have been be interesting to change the configuration of the bus bars, just to eliminate the possibility of a misaligned terminal or damaged threads like cell #6 in the old battery.

[@OffGridGarageAustralia]

Thanks, Steven. Yes, absolutely, I will repeat this test with a 8s or 16s battery in the future so we can test more materials and connections.

[@matthiashoffmann4149]

@@OffGridGarageAustralia have you already repeated the test? would be very interesting. As steven said, would be nice to mix the busbars and interchange them just to make sure its the busbar itself, not the terminal or internal temperature heating up of the cell itself.

[@ominguti6345]

A great test, thank you. Very different that I had expected. Aluminium should be as good as copper when there is double the area and the awg 4/0 cable is 3x the area of the original busbar, so how on earth could it be worse?!? The answer must be connections to the posts and perhaps crimps. Tin is a very soft metal. Although there isn't much of it on a tinned busbar it must be improving the surface contact somehow in a way aluminium doesn't. Likewise for the crimp ends of the wires.

[@georgescott6967]

Maybe it is just me, but I'd call those things "interconnects". I think bus bars are different - in wiring up a battery a bus bar would be used when connecting the cells in parallel.

[@OffGridGarageAustralia]

Yeah, OK, that makes actually sense as well. It's just another word. I used to work in switchboard manufacturing and we called them always a busbar if they are from solid copper material and not a cable.

[@Stephen2846]

Hi Andy, Greetings from the USA. A suggestion on the Buss wire and bar test connections. Switch the different test buss components to different cells and repeat your test. It's quite possible that the heat is actually coming from an internal cell connection. You may have hot cell terminals heating the buss material through thermal conduction. I realize that the aluminum is heating from the current it's carrying but if you have hot terminals you need to ensure it's due to an external connection rather than an internal one. Marking your hot cell terminals and the putting your cold buss links on that cell will tell you whether you have a bad terminal, bad terminal connection, or undersized buss conductor.

[@user-sm3xq5ob5d]

Makes sense. If the busbar itself is the issue then there should be a gradual change in temperaue from the hotspot to the "not so hot" spot. And not a sudden change with a visible separate temperature zone. My guess is also the cell underneath the busbar is radiating heat to the bar.

[@napalmholocaust9093]

I picked aims over a renogy inverter based on reviews. Ren seemed to have reports of complete failure of the boards in as little as 3 uses. Many failed before 2 years if they can be believed. I think aims has lower standby consumption too. I consider it important.

[@theoff-gridhouseinrome3598]

Hi Andy great video as always, in regard to the busbars I have to say thay I had a problem we the alluminium, ones and to solve the problem I changed it with the pure copper semiflexible ones; the problem with the busbars is caused even by charging/discharging the battery at high currents.

[@OffGridGarageAustralia]

So, has the copper bus bar resolved the issue?

[@theoff-gridhouseinrome3598]

@@OffGridGarageAustralia Absolutely yes it solved the problem immediatly.

[@sreekumarUSA]

032822/2107h PST 🇺🇸. Danke Herr Andy. Understood the importance of transfer of power and the torque standards. I’m highly impressed with the flexible bar, because , even though it had 5 joints at each sides( the flat plate compressed to Cu braid and the Al battery threads, SS grub bolt, and the knurled SS nut) on one terminal; it ( flexible BB) surprisingly stayed cool. I’m not surprised at Madam Matty’s ( sorry if I misspelled the name) 2 cable bus bars, that stayed cool, because they both are AWG4. (4X10AWG=4 AWG) But, No comments on Al BB because it was a gift.😬 The normal Sn plated Cu bus bar, tested at China Labs and found suitable for the occasion, so it stayed cool. If you are asking my opinion, I’d say, stay with flat pure Cu bar 3~4mm X 20mm drilled elongated and smear MG Chemicals Carbon Conductive Grease #846-80g. The CCG will not harden and takes away all the joint (electrical) issues. Beware… the compound is messy messy and very messy. I have pronounced lewd verbal epithets while installing the same🤪. Do forgive if I exceeded my limits. Take care und 73s…

[@mediocre_moto]

Some really interesting results there Andy, a real shame that the braided "bar" was 1-2mm too short with the holes - I wonder if some feedback to the manufacturer would help? I understand that it takes a LOT of time to do tests like this properly, but I would be very interested to see the different bars moved to different batteries/posts to see if the heat behaviour follows the bus bar, or whether certain battery posts are contributing to the heat/resistance. Keep up the great work mate!

[@OffGridGarageAustralia]

Thanks James, I'm in contact with the manufacturer of these busbars because of this issue. Yes, that is a good point to do the cross checking. I'll repeat this test at a later stage once other things are out of the way...

[@davestech6357]

Buy some 2 gage welding wire and crimp good quality ends to length and use "Soft Copper Crush Washers" on top. Yes, crush washers.

[@marcorobbe9003]

Hi Andy, I have not read all the other comments, if someone has written this. These flexible "busbars" are normaly more used to connect an electrical kabinet with its door and also in kombination with high frequency topics. As I know high frequency current is flowing only / better on a surface. Because of that this connectors are made. All this tiny wires are giving a much bigger surface than a solid wire / busbar. (Don't kill me if I am wrong, but as I know this is, what the flexible connectors are for.)

[@dennispayton4366]

Thank you Andy for doing this video. I was just about to make some fixable bus bars. But notice how both the fixable bus bar and the aluminum bar on the ends were cool. what would happen if you changed them and put them in the center and the other bars on the end. It seems that most of the heat is coming from battery post to battery post. 🤔

[@OffGridGarageAustralia]

Thanks Dennis. I haven't had time to do more testing but I will do another test with an 8s setup at some stage where we can test more materials.

[@USA-GreedyMenOfNoIntegrity]

140 original tin plated copper bus bars used on my 132kWh battery with 847 carbon conductive assembly paste. All cold as cucumbers.

[@upnorthandpersonal]

+1 for 847 :)

[@OffGridGarageAustralia]

Thanks for sharing. I wasn't aware that cucumbers are a measurement of temperature 😁

[@OffGridGarageAustralia]

OK, ok, ok, I've ordered this goop as well now!

[@stevesays8705]

Please test „Noalox“ with conducitve powder in the paste!

[@Electronzap]

Nice test. Just subscribed.

[@FutureSystem738]

Thanks Andy, great as always. It’s a rainy day (yet again ;-( so I’m catching up on your videos. SPAT for the win. (With the horrible tragic events happening on the other side of the world, far too close to Finland for comfort, maybe being totally sustainable off grid is a very good thing indeed. Sad!)

[@lezbriddon]

just received my jk bms after seeing your 'reviews', i'm really happy with how its balanced the pack.

[@OffGridGarageAustralia]

The JK-BMS is really great and works a treat.

[@lezbriddon]

@@OffGridGarageAustralia being a big bike build I went for the 24s to get a high voltage but didn't realise there's no serial port on it so I can't pull the data off to the bikes main diy LCD screen, I'm looking at trying to connect an Arduino to it via Bluetooth just so I can display amps and volts alongside bike mph

[@xuerian]

I'm not experienced with this issue but in other videos with thermal cameras I've seen a lot of discussion about measuring some surfaces and them not being able to get useful measurements with some materials. Usually it comes up that something extra is needed to get an accurate reading, which I think is perhaps applying a matte black thermally conductive tape to the surface and measuring that instead? Have you considered this sort of effect with thermal cameras? Of course it really doesn't matter in this case since you're using your hand anyway, just a side note. Edit: It looks like Fluke has a good simple guide on measuring reliably

[@gabbertje2811]

Everything reflective cannot be measured with a thermal camera. It is like filming a mirror and you will only see the thermal reflections of yourself and your surroundings. Also, if you want to measure something behind a see through lid (or a window) than it is best practice to remove the lid when measuring. A good example is to try to film outside your home from behind a window. You only will see the thermal reflections of the inside of the room you are standing in.

[@chevrofreak]

I have a thermal night vision setup and I can confirm this. A K type thermocouple may give more meaningful answers.

[@bloepje]

I want to start experimenting for a new off grid house. But this video just again proofs: if you are going to do high current in any way, a good IR cam is a necessity. So that's probably the first thing I will investigate. But I'd rather have a good usb/phone version, because I can install a usb/phone version later on a PI to watch the installation.

[@camielkotte]

I love how you casually insert the chickens. That made me smile. BTW my 280ies are installed and work reasonably fine thanks to you (and others over here) . I still am wondering which busbar is for higher loads. I suspected the braided busbar would be best. But slightly expanded cells will probably start pulling on the battery poles? If it fits at all. Therefore I really like the single 1AWG wire diagonally connected. Getting it crimped with good lugs that would be my choise

[@philipreich7035]

Hi Andy, I wonder if the aluminum buss bars would work better if you removed the oxidation layer from both sides of the buss bars, and also did a light sanding on the aluminum on the battery themselves -- and of course liberally used the anti-oxidation goop everywhere you sanded. I'd also be interested in seeing if using a brass or bronze stud and nuts would be better than the steel ones, as the brass or bronze should also conduct better. I would be interesting to see a re-test with those changes.... Philip

[@berndausdemallgau3743]

Great Video, greetings from Germany

[@Ivansgarage]

Most people don't understand about resistance, not just the wire size, but the strands, "electrons travel on the outside of the wire or bar" so if you use welding, welders cable, a 4 gauge welders cable, "picking random numbers" might have 50 wires, where as a house wiring 4 gauge wire would only have 25 wires... hope this makes sense....

[@L.V-Rider]

electrons travel MOSTLY on the outside of the wire or bar

[@ZoeyR86]

I used 3/8 copper pipe squished flat. When using a thermal camera i recommend painting a strip of flat black paint on them so you can get the accurate temp and not reflections

[@gelecopter]

Here is actual resistance and power loss on the bus bars tested in this video: EVE Orig　R=0.045mOhm　Ploss=1.152W SuperAlu　R=0.15mOhm　Ploss=3.84W 4x10AWG Flex.　R=0.0875mOhm　Ploss=2.24W 1x4AWG Flex.　R=0.106mOhm　Ploss=2.72W Ali 'Flex'　R=0.031mOhm　Ploss=0.8W Calculated base on measured voltage drop with 160A of current. Ideally it would be best to measure on the battery terminals with high input impendance multimeter because bolts are carrying a little bit of current too and measurement would not be true. Kind of. As for thermography - it is a good idea to use black sharpie on your shiny metal parts...

[@pilgrimvalle]

now that is good information....thanks

[@OffGridGarageAustralia]

Thanks for doing this additional maths and sharing it here. The overall test was more to show that the problem is with the connection and not so much with the actual material of the busbars people choose.

[@TheYoungBoaty]

Hi, Andy, have you also tested stainless steel 304 nuts or serrated stainless steel 304 nuts would change the resistance of the same bus bars with same torque, would different nuts affect the current flow of the bus bars and results of your BMS? How about adding a layer of aluminum foil under bus bars or above bus bars to reduce resistance? I am going to use nickel plated bus bars with serrated stainless steel 304 on batteries in series, then apply dielectric grease to prevent corrosion and arching but now I would consider to use graphite grease to reduce resistance and corrosion without attracting dust. I am going to get a clamp meter as my multimeter would not test current other than 1.5V and 9V batteries. I figure this might be related to contact resistance and I am sure that different torque would even change voltage and current.

[@fancentral4662]

Blogs are quicker to read than video

[@maximilianreichelt9717]

A comment to the charging resistor. I also use anti spark resistors. Around 10 Ohm. Make sure to disconnect the resistor, when the big connection is made. For that i have installed a little fuse with a switch on the positive terminal. After the switch is the resistor soldered into flexible wire. At the end i use an alligator clip for busbars or a short solid wire for breakers. With that i have one to both hands free to make the connection and have no time pressure before the capacitors in the inverter discharged again. With this method i have absolutly no sparks. I don't like these battery resistance meters. Because many measure with AC. The result is useless, because batteries are used with DC. This measuring method is better for capacitors, where the frequency is important. For batteries i always use a dump load and measure the voltage drop.

[@williamhustonrn6160]

Great video Andy, I am curious how my DIY busbars would test out in your testing environment. I made mine from 1/2" (12.7mm) copper tube that i flattened in bench vice and punched holes that i made from a 10ft section i bought from hardware store for $13USD. Your braided test results has me intrigued as i wish more flexibility in my busbars and i just went and picked up a small section of copper braid wire that they commonly call "grounding braid wire" here in the USA for $2.74/ft and going to use copper tube as ferules on the ends. I previously plasti-dipped the copper tube diy busbars for insulation, so i am unsure if i should insulate them or not, it seemed them being bare was cooling the busbar combared to the insulated wire busbars.

[@ForbiddTV]

There are websites that sell flat or round copper braid profiles in many sizes by the roll.

[@pilgrimvalle]

insulating them does cause them to retain heat a bit....no longer has the natural radiator effect to get rid of the heat as the electricity flows through them...

[@Harvey307]

@ Andy is there some reason you don't use a conductive paste? I do build up welding with a mig welder for hours at a time 22-24 v 220-240 amps if connections get hot I use a conductive paste (can't recall the name) of it but it contains graphite I pull the connection apart clean it apply the paste and the heat is gone.

[@OffGridGarageAustralia]

Well, the test has shown, it's not necessary. Except the aluminium bus bar, all others staid cool.

[@gumpster6]

Interesting comparison - thanks Andy. The only scary bit was the flexible braided bar hanging over the edge of the cell. I seem to recall hearing the outer shell of the cells is tied to negative. Had the braid touched an exposed bit of the shell under the thin blue plastic covering that might have been ugly.

[@OffGridGarageAustralia]

The case of the battery is actually the positive. There are also two layers of heatshrink/insulation in this corner area, so it was safe of doing it this way for the test. Not for a permanent setup though.

[@gumpster6]

@@OffGridGarageAustralia Oh, it's the positive... I guess I mis-remembered - thanks for clarifying. I figured you would have realized if there was any risk.

[@d.h.s.d616]

Very nice

[@OffGridGarageAustralia]

Thanks

[@garys-half-baked-offgrid-dream]

Hi Andy absolutely brilliant test and valuable evidance. Aluuuuuuminum is a git and oxidizes extreamly quickly, you did the right thing protecting it with paste asap. For those of us on an extreamly tight budget, Can I ask you to do the same test but with an upsycling hack re-using flattened and drilled copper plumbing pipe of various sizes? I had used Scrap cable off cuts of crimped (with your hydrolic hex press)and exact lengths but that was only for initial charge, ballance and test, no high loads as yet. Loving your work thanks Andy

[@OffGridGarageAustralia]

Thanks Gary, I'll do some more testing with different materials in the future and will include some copper pipe as well.

[@garys-half-baked-offgrid-dream]

@@OffGridGarageAustralia Thanks Andy that will be cool!

[@raystone4673]

Good video. You seem to be able to cover everything over a period of time. Yes the punched round hole leaves extended "burr" on exit hole. A larger hand-held sharp drill-bit can be used to remove it, leaving a mild countersink lip around the hole, if rest of surface is flat. The fact that busbar suppliers make the slots in the supplied busbars wider than 6 mm for an M6 threaded terminal post, is annoying. M6 threaded objects are slightly less than 6 mm, so a strip made with a 6 mm wide slot will fit on it. This ensures more surface contact area and less resistance. Yes those braided straps were probably more suitable for a time when a smaller, thinner battery was more popular, and they haven't allowed for the minimal new distance increase of the 304 model. For someone who has them, the hole could be elongated in the desired direction with a small coarse round file, or a filing drill-bit you'd put in a power drill. Not sure of the name. Nice thing about the braided ones is they're all copper so 65% better conductivity than Aluminium, and you could piggy-back them (if you're wealthy), for 100 sq mm of connector cross-section. You could then compress cells or not, as the strap just humps up if cells closer together. There are flat washers available, which are much bigger than the standard, but with the tight 6 mm hole, to put under the nut. I've seen others, 2 or 3 mm thick, which when bigger than standard, also eliminates "cupping" of the washer or lug when under a small diameter nut. These could end up better than just a flange nut. Love your camera and torque wrench adaptor. Must buy both very soon.

[@PowerPaulAu]

Interesting results, but something is not quite right there. The IR v's Voltage should be consistent (basic ohms law) because the current flowing through all of them is consistent, so the readings aren't coming in correctly. Also the end connections aren't consistent with middle ones because they're not terminated to another cell. If you built up a 16s 48v pack, and ran your other inverter to do the test, then place these 5 different bus bars in the middle cells, that would provide consistent connections throughout. Doing this you could also do 3 of each type of bus bar so you can triple confirm each reading and get an average. It still seems like the connection between bus bar and terminal is an issue too. I know I do my nuts up to about 8Nm, maybe 4Nm isn't quite enough. The other thing I have just been alerted to, is that the longer Aluminium bars that you have (sized to do the end-end connection), may actually be a different material grade. They are from a previous supplier who didn't actually specify the grade, so it's likely that the newer ones I have sent will produce a better result. It's a lot of testing to do to revisit all of this, but we're cheering for team Andy to get results :)

[@mattobrien1085]

Might be worth looking into water jet cutting rather than laser cutting. Laser will always produce a little lip around the perimeter that needs to be buzzed down, especially on thinner material

[@OffGridGarageAustralia]

Thanks Paul. As someone pointed out the problem could be the internal resistance meter not been reliable when measuring under load and having high ripple on the DC (100Hz ripple from the inverter). The results are in deed questionable in this case and hence I said at the end it was not so much to compare different materials but more to point out that the resistance between terminal and bus bar is the problem.

[@fossil4160]

Ths Andy, Looking at the 304 a/h cells supplied to me I can see a step in the terminals which could allow a larger contact area & increase the current contact area with larger hole sizes. May be worth a look at? Regards Bill

[@maraudx]

thank as always for your great videos. for the record, as it made me laugh, I prefer a blog over a video most of the time. that’s just how my brain most efficiently consumes new data. 😝

[@OffGridGarageAustralia]

Thanks Sean. I'm glad we have both, videos and blogs, so everyone can choose what they prefer.

[@ennyw20]

Sehr spannend.. Hast meinen Text unter dem anderen Video gelesen? Es ist war mir nicht so wirklich klar das nicht unbedingt das Material entscheidet sondern die Verbindung.. Gut so hohe ströme hab ich kaum aber ist echt übel das mal so zu sehen.. Danke Andy

[@OffGridGarageAustralia]

Hab noch nicht alle Kommentare gelesen. Es sind zu viele 😁 Alle Metalle sind gute Stromleiter. Du koentest sogar eine Sammelschiene aus Stahl nehmen und das wuerde funktionieren. Das ist nicht wo der Widerstand sitzt. Es sind die Verbindungsstellen, Oxidation, Verunreinigungen und Unebenheiten, die eine Erwaermung verursachen.

[@dollyone3714]

i set up is 16s 2p 200Ah LFP cells, my best busbars are 25mm² copper cable with SC25-8 copper lug and 3mm thick 1 inch wide copper plate.

[@Dirt-Diggler]

IME of automotive and marine electronics, 90% of issues are the connections, usually solder joints cracking followed by contact points needing a good sand down and re seat or replacing connection terminals Surprisingly (not to me) crimp joints are by far the least problematic area of an electrical system 👍

[@OffGridGarageAustralia]

Thank you. That's exactly what I found too. The IR camera doe s a great job revealing these weak points in your system quickly. The crimp connection of this cable leading to the inverter seems to have a problem and gets really hot. I removed the heat shrink but could not really see a problem. I may just re-crimp it...

[@alexandergunda8916]

Hi Andy, great test, thank you! This confirmed my gut feel that the original bus bars are fine. About the flexi-Ali bus bars "don't fit" I think that applies only for your huge batteries, for the "normal" sized ones they probably would be fine. Right?

[@OffGridGarageAustralia]

The original busbars are actually pretty good considering they are 'free'. No, that does not matter which cells you use. The EVE LF280/LF304 have the same terminal distance. I've got some new ones now which have the welded stud and they have different distances between the termerminals.

[@alexandergunda8916]

@@OffGridGarageAustralia I was referring to the 176Ah (which I use) or even lower - the "poor people" choice 😉, they are definity slimmer. SRY for not mention it before.

[@John-gm8ty]

the link in the description for the Rnogy inverter is for the US one, just a heads up.

[@dan2304]

Andy, measuring the voltage drop and resistance of the bus bars from the stainless steel grub screw is erroneous. To get a true measurement of the connection, voltage drop and resistance the measurement needs to be taken directly from the battery terminals. That way the resistance of both the connection of the bus bar to the terminals and the bus bar itself are measured, which is what is important.

[@CollinBaillie]

As Andy has said in many replies over a number of his videos, once the bus bars are on, he no longer has access to the actual terminal. They are completely covered by the bars. So he has the terminal screw, or the bar itself, that's it. And I see he in fact measured from both of these options in this video, albeit in different tests.

[@dan2304]

Not being able to access the battery terminal does not change the reality of the correct way to measure the bus bar connection, voltage drop and resistance.

[@CollinBaillie]

@@dan2304 Guess he has to become a magician then. Or are you saying he should just never perform these tests?

[@dan2304]

All i am saying is that when measuring it is important to know what you are actually measuring. In the video Andy is not measuring what he thinks he is measuring, while it may be close. To get a correct measurement of the bus bars it has to be done from the battery terminals.

[@CollinBaillie]

@@dan2304 right. Thank you for explaining. 😊

[@ForbiddTV]

That's real interesting about the braided bus bar, anyone know how difficult they would be to make? I found suppliers that are copper braid suppliers, such as Arcor Electronics, and have them in rolls up to 1000' in flat or tubular designs in many cross section profiles.

[@OffGridGarageAustralia]

Thank you. You would need the right end-caps made from tinned copper and the tools to crimp them. I think Up North and Personal made his own... somehow...

[@upnorthandpersonal]

@@OffGridGarageAustralia Yes, I make my own. End caps are just pieces of (annealed) copper tube, compressed with a small hydraulic press (a manual one, around 10 tons should do). I nickel plate them using a nickel acetate solution (made with vinegar, a power supply and some pieces of nickel).

[@daniele9160]

Hi, some advice, I need to extend an equipotential bar, is it possible to join it with two 8 bolts instead of doing it all over again? or is it not recommended? Thank you

[@Dutch_off_grid_homesteading]

Heya, I really need to get myself this flir cam, it's olso good for finding shorted capacitors or differant shorted item's on pcb's

[@zoe..d]

So, having always seen the options in your videos for BMS having separate resistance values for balancing, does this provide any real world advantage in speed of top balancing your battery bank's? Or is it just simpler to rely on equal length balance lead lengths and connection methods and let the BMS auto distribute the current? I still can't fathom why the options are in there for individual resistance values.... Thanks again for all your learning and sharing Andy!

[@OffGridGarageAustralia]

Thanks Zoe. Different lengths of balance cables don't play a role as such. When the BMS measures voltages, there is pretty much no current flowing, therefore no voltage drop. I think the JK-BMS just measures the resistance of the balance cables. I'm not 100% sure either why it may be important though unless you have a real bad connection and it has trouble pushing these 2A through such a cable.

[@zoe..d]

@@OffGridGarageAustralia thanks Andy! Does this mean the issues with your V1 battery bank coupled with the QUCC BMS having such a high millivolt deviation is due to not having balancing while charging activated in the app settings or actually the cells individual behaviour? Happy spat hour to you :)

[@erikrezlman7900]

Great video Andy, but please be careful with your ring over your batteries while touching for heat! Did that, only once, over car battery and touched my class ring somehow over battery and it arched my ring and burnt my finger! Great content.

[@OffGridGarageAustralia]

Thanks Erik. I guess this can only happen when the ring touches both terminals. Or having a bare wire in your hand which touches the ring and it also touches the other terminal? I never understood how such accidents can actually happen..

[@tanishqbhaiji103]

You can get decent cells for a good price in India, I know of an LFP dealer who stocks EVE cells and maybe other brands too, if anyone wants details, reply to this comment.

[@hamadalthani7535]

Thanks

[@claesmansson9070]

Not a problem if a busbar acts like a spring,one is supposed to compress the cells anyways, woven busbars can change in length too like your underpants even if I use neighter of them.

[@westking7746]

By the buy, I like the crimped copper cable approach from digital mermaid. I will probably be using them. My batteries will be custom sized made from 32650 6ah cells from Battery Connect, so I will need custom bus bar lengths.

[@pau1phi11ips]

I think Madi's cable is supposed to go diagonally across to the next cell so you end up with all the positives and all the negatives the same side. That's why it's too springy in the default side to side layout... Maybe

[@TheDigitalMermaid]

Nope, he used it as I intended. If you see in the original video I did, I tried shorter cables but they were too stiff. I had to go that long to give them enough spring to let the batteries touch. When the batteries are in the box, the spring of the cable doesn't push the cells apart or even press hard. With only four cells loose on the bench though, the spring is enough to push them apart, barely.

[@OffGridGarageAustralia]

I think it's in this video, Paul: kzbin.info/www/bejne/sGnKeHpqdrWShrM

[@peters619]

Andy - was this a fair test? Didn’t the first and last bus bar not have a heat source on one side of them? Can you repeat the test and move the same bus bars around to put a heat source on both sides of every bus bar

[@OffGridGarageAustralia]

THey didn't have an aluminium busbar connected but just the cables to the inverter torqued with the same 4Nm. I can repeat the test with a 16s pack in the future so we have more opportunities to test different materials the same way.

[@davyp2993]

hmm,? Am I missing something.? Surely it is about the current carrying capacity of the busbar. For a start, aluminium will only carry about half of what copper busbar carry, of similar cross section. On your test you go from the cross section of the cable to how much crimp is touching the terminal, therefore reducing the cross-section and producing heat. That is why the cell terminal has such a large area of bare metal, the bolt is only to secure the crimp in place, not carry the current. Try what I call "penny" crimps they have a larger pan with a small hole, and use a washer the same size as the crimp pan. I use 70mm2 orange welding flexable cable with the crimps, only crimped with no solder. My cells are 3.2v 500ah x4, 12v, and drawing 3000w for an hour and nothing gets warm. Looking at the crimps you use and what I have seen on other channels, they look like they are from a DIY store, go to an electrical wholesaler and buy industrial crimps. They are are made by squashing the end of a tube to create the terminal end giving you twice the thickness of crimp at the terminal.

[@JN-ou9ws]

Hi, If I'm not mistaken when you connect in series you battery AH stays the same as a single cell. So it would make it a 300+ AH 12v bettery. Os this correct?

[@quattrohead]

Aluminium is not a great conductor like copper and is a serious pain to use properly. I don't know why people are re-inventing the wheel (or busbar in this case) the busbars that come with the cells are perfectly fine.

[@CollinBaillie]

For science! Not everyone knows everything. Andy gets to make content, and people who enjoy his content get to learn WHY industry has standard preferences for materials used. Also, perhaps aluminium is more budget friendly, if you're willing to take the time to understand the problems and deal with them properly. A casual viewer may well walk away with a partial understanding only, thinking any old aluminium bar would do, and that is a problem. But casuals will be casuals. You can't change humans.

[@repairman2be250]

Agree on that point as well.

[@OffGridGarageAustralia]

@Quattrohead. On this channel I make tests and share this with everyone. If you want a ready build battery which just connects and works, that's the wrong content then for you. I'm here to test, explore, learn and share. That's the main purpose. Also, in this case, the aluminium bus bar has a lower resistance than the standard copper bar. I made a video about it when I got these aluminium bars.