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Cell Terminal Strain Relief, bus bars, and compression

I am trying this flexible buss bar.


534011​

NVENT ERIFLEX, ERICO Flexible Busbars, Eriflex Flexibar Series​

534011 Part Image
 
I am trying this flexible buss bar.


534011​

NVENT ERIFLEX, ERICO Flexible Busbars, Eriflex Flexibar Series​

534011 Part Image
Looks very good - but where are you sourcing them in small quantities?
 
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I am in the PNW, I am building three eve 280ah 12 volt packs if I have extra I will let you know.
 
I am in the PNW, I am building three eve 280ah 12 volt packs if I have extra I will let you know.
Sure - keep the Forum informed as to how this work out for you.

I think the bus bar issue is the weakest link in these cells. I have had to remove mine twice this year to clean and re torque due to voltage fluctuations...

I'm going to try the MG Chemicals 647 that Upnorthandpersonal recommended.

I am also in the PNW, but on the Canadian side of the border.
 
@S Davis Do you considea these flexible as in the back and forth between the cell expansion and contraction, or is this bar flexible as in bending it into a C, but not so much in strain relief on the terminal?
 
The bar is flexible enough to make bends, I could bend a v for expansion length wise if it is an issue but I think going diagonal will alleviate most of the issues. This is for a mobile application so I will be monitoring the connections closely. Both 280ah banks are being mounted on vibration isolators.
 
I forgot to update my own thread on my progress! I ended up making wire interconnects. I used AWG 4 (ampacity 160a) for the parallel connections, and AWG 1/0 x 2 for the serial connections. Each 1/0 cable has an ampacity of 285a, so total of 570a for serial connections. I'm happy that they have some give to them, and I feel wires and terminals are very solid and reliable technology. I've fixtured the cells with 1/4" aluminum end plates, 7 threaded rods, and springs. If someone wants the dxf file for hydro-cutting the aluminum end plates, I'm willing to share, just let me know. It cost me $100 for the cutting, and about $30 for the aluminum. In between each cell is a thin sheet of silcone mat, which is heat resistant, vibration damping, and importantly, an electrical insulator. It sticks to each cell like cling wrap, no adhesive needed. The whole thing is on a thick silicone mat, and strapped down. I'm happy with how it all turned out, and I'm currently using it on my boat (family of 4 live on it). Thanks to everyone who helped me get to my final design!

IMG_0121.jpegIMG_0019.jpegIMG_0016.jpegIMG_0041B .jpgIMG_0014.jpeg
 
What thickness aluminum plate did you use, and can you give a link to the silicone mat?
 
The bar is flexible enough to make bends, I could bend a v for expansion length wise if it is an issue but I think going diagonal will alleviate most of the issues. This is for a mobile application so I will be monitoring the connections closely. Both 280ah banks are being mounted on vibration isolators.

How have the bars performed in your setup so far? Any issues?
 
How have the bars performed in your setup so far? Any issues?
Everything is going good so far, I am waiting on a 2800watt inverter and have only been able to discharge at 30 amps and charge at 50 amps. All the cells are staying nicely balanced no loose connections, they get bounced around a lot. I am putting together seven 280ah batteries, just finished top balancing number three.
 

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Everything is going good so far, I am waiting on a 2800watt inverter and have only been able to discharge at 30 amps and charge at 50 amps. All the cells are staying nicely balanced no loose connections, they get bounced around a lot. I am putting together seven 280ah batteries, just finished top balancing number three.

Thanks for the reply. I also purchased the same Eriflex bar and just cut one bus bar to see how flexible it can be at this length with the three layers. I am finding it a bit stiff for the purpose of avoiding stress on the terminals.

The diagonal setup sounds like a good idea; I am wondering if twisting the bus bars would also help give some flex in the contraction-expansion axis.

Erico also lists a bar with two layers (same layer thickness and width) in the 250A category, but the current carrying capacity would obviously not be as good. In the bus bar I cut so far, I did pull out the layers and using two layers only would have enough flexibility IMO.
 
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I will give them a year of expansion/bouncing around while monitoring the terminal connections and see, if I start having issues I will look at alternatives.

With them mounted on vibration dampers I think they will be fine, and it makes parallel top balancing easier with the diagonal connections also.
 
After trying a few solutions to the flex-able bus bar issue for mobile applications, I am now using these very flexible busbars https://www.aliexpress.com/item/1005002755728521.html?spm=a2g0s.12269583.0.0.548b4d2eq9IcCJ.

These were also mentioned above in this forum thread.

At around $4 usd a piece, they are very good value.

With my prior busbars, I was having problems with resistance in the busbars over time ,giving false BMS voltage readings and prematurely tripping HVC.

To avoid stacking ring terminal over the busbars, I drilled holes in the corners of the busbars for #4 bolts & nuts to hold the sense wires.

I also am using the MG Chemical 847 conductive paste recommended by Upnorthandpersonal to protect the EVE's aluminum terminals from oxidizing and to promote a good electrical contact.

It's early days, so will have to see how this new setup lasts over time.

MP


IMG_7339.jpg
 
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How flexible are they? I wonder if someone could show it (bending or something?)

(watched video below: oh, that is very flexible ?? )
 
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After trying a few solutions to the flex-able bus bar issue for mobile applications, I am now using these very flexible busbars https://www.aliexpress.com/item/1005002755728521.html?spm=a2g0s.12269583.0.0.548b4d2eq9IcCJ.

These were also mentioned above in this forum thread.

At around $4 usd a piece, they are very good value.

With my prior busbars, I was having problems with resistance in the busbars over time ,giving false BMS voltage readings and prematurely tripping HVC.

To avoid stacking ring terminal over the busbars, I drilled holes in the corners of the busbars for #4 bolts & nuts to hold the sense wires.

I also am using the MG Chemical 847 conductive paste recommended by Upnorthandpersonal to protect the EVE's aluminum terminals from oxidizing and to promote a good electrical contact.

It's early days, so will have to see how this new setup lasts over time.

MP


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I am considering these busbars in my mobile application (van), but I have a question. My current commercial braided busbars somewhat feel spongy when I tighten the nuts, and I suspect this, along with vibrations, caused some of the nuts to loosen over time (the connecting sections on the busbars were probably not pressed hard enough - or were made for larger studs and higher torque). In contrast, the nuts on B- et B+ lugs in both my batteries remained tight.

When you tighten or torque the nuts, do you somewhat come to a hard stop?
 
I am considering these busbars in my mobile application (van), but I have a question. My current commercial braided busbars somewhat feel spongy when I tighten the nuts, and I suspect this, along with vibrations, caused some of the nuts to loosen over time (the connecting sections on the busbars were probably not pressed hard enough - or were made for larger studs and higher torque). In contrast, the nuts on B- et B+ lugs in both my batteries remained tight.

When you tighten or torque the nuts, do you somewhat come to a hard stop?
I have no way to measure.... but they seem as hard or harder than the lug connections on cables. Hope that helps.

Maybe try Nord-Lock washers?
 
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