DIY bus bars using twisted copper cable

ScottWCO

Solar Enthusiast
Joined
Feb 4, 2021
Messages
42
5F27E462-4063-40D4-BBC3-AEEFC0EDD38F.jpegHey gang -

I’ve got some LiFePo4 cells on order, and they’ll come with the usual set of bus bars and posts. But I’ll be building these packs to go into a van build, so beyond the usual concerns of the effects of expansion/contraction of cells on the bus bars and posts, there’s the added factor of vibration/rattling around.

I’ve been seeing where some folks have been using 4awg cables instead, crimping ring terminals on the ends, to handle both situations.

Lately I’ve been working part-time for a couple of friends who have a business making thermal transfer solutions for aerospace use, and much of what they make is made largely out of twisted copper cable. I chatted these guys up this morning about how well that material would work as a substitute for the usual bus bar, and they say it would be the equivalent of the 4awg cabling mentioned above.

I wanted to throw this out to the peanut gallery and get opinions, so have at it :)
 

OffGridInTheCity

Solar Addict
Joined
May 23, 2021
Messages
447
Location
Southern Oregon
I use 6awg soft drawn, stranded, bare copper wire for my 18650 pack bus-bars with good results. I think the key thing is you have to fabricate fasteners to your LifePo4 cells which is a lot of work compared to simple metal plates with screw holes. Other than the extra work - if bent a little between cells it should be flexible etc and work great.
 

ScottWCO

Solar Enthusiast
Joined
Feb 4, 2021
Messages
42
I use 6awg soft drawn, stranded, bare copper wire for my 18650 pack bus-bars with good results. I think the key thing is you have to fabricate fasteners to your LifePo4 cells which is a lot of work compared to simple metal plates with screw holes. Other than the extra work - if bent a little between cells it should be flexible etc and work great.
Bare - no heat shrink? No brush-on insulation (silicone I think? I'm trying to remember what my guy mentioned when I quizzed him on the topic)?
 
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