Busbar Cable choice

Earlonics

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Hi Folks, is anyone in the UK using 2.5mm2 T&E to create their busbars?

I intend to use 3 x 2.5mm2 solid core twisted, but I'm also aware about the potential draw from each of my 14s 100p packs when built.

Everyone seems to talk about using 4mm solid core, unfortunately here in the UK if I go for 4mm I can't source it as solid core its multi stranded.

Since myunderstanding is that 2.5mm is rated at 30 amp giving me the potential current carry capacity of 90amps per pack would this be consider to small for each of mypacks, I would obviously be using larger cable between each pack, for this I was even thinking of cutting up heavy duty lorry Jump leads does anyone have a concerns on my approach.


Thanks in advance to all you wise one's
 

daromer

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I use 2.5mm2. they are rated for Up to 25a in household. I use 3*2.5mm2 in 2 rd so thats basically 6*2.5mm2 and more than enough for My calculated 80a max.

 

Oz18650

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Why does it matter of you use solid core or multistrand?
If you are twisting your own bus bars, add or subtract to get the cross sectional area / current capacity you want them to carry.
If 3 x 2.5mm2 is not enough, why not use 4 x 2.5mm2?
 

Earlonics

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Thanks Oz18650 for your input, your right in theory it doesn't matter if I user either, providing what I do use can carry the amperage.

My question was brought about because to me it seems most builds use solid core in preference to multi stranded, and I wondered if there was something I was fundamentally not understanding.
 

daromer

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You use what you get and make sure crosssection is enough. As said i use 2*3*2.5mm2 on all my packs since 2.5mm2 is easy to get hold of
 

Oz18650

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Earlonics said:
Thanks Oz18650 for your input, your right in theory it doesn't matter if I user either, providing what I do use can carry the amperage.

My question was brought about because to me it seems most builds use solid core in preference to multi stranded, and I wondered if there was something I was fundamentally not understanding.

Cool.
Maybe I am missing something too, so thanks for asking.
I am not at the point of building packs yet, so the right/best way to design and make the bus bars is of interest to me.
From the video he posted Daniel's twisted bus bars look very neat and tidy.
I wonder if multistrand ends up as neat, when done well?
Certainly the hand twisted multistrand wires I made for my tp4056 board do not look that neat, but that was done purely by hand, so I am sure a better result is possible.
 

Korishan

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Earlonics said:
Thanks Oz18650 for your input, your right in theory it doesn't matter if I user either, providing what I do use can carry the amperage.

My question was brought about because to me it seems most builds use solid core in preference to multi stranded, and I wondered if there was something I was fundamentally not understanding.

Not really. Just that 14AWG is fairly common in most locations in solid core. In the US, we have solid core all the way up to 6AWG. I think 4AWG is when it goes stranded.

Wire is wire, and as only as it's the right squared measurement (mm or inches), it doesn't matter what you use. You could even use a solid steel beam if you'd want. tho, that'd be hard to work with :p
 

Earlonics

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Thanks every one for the useful information and insight, my journey continues.
 
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