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Neater way to connect prismatic cells?

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Boron

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I saw this on another members post but lost the link? Maybe some knows?

We all know what a mess you can end up with, connecting all those cell volt little wires back to the BMS, so here's something so obvious and so much more tidy. What do you think? Laced connections (longer flexible busbars, or cable/ring terms?) From a mechanical view I find the hard connection using solid busbars puts stresses on the M6 studs and the sealing with the casing? Doesnt feel right. But those crimped multi-leaf versions are $$$. BTW this is what I use cos Im cheap. Its a copper tube wall clamp ca 10p ea. The csa is ca 3mm^2 so good for 50A, - my load max. Double up for 100A? Love your Plumber.
 

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If you are saying that you use a plumbing pipe strap for a bus bar, that would be a big HELL NO!
Copper Electrical conductors are made from pure copper. Plumbing straps don't even come close. They are usually made from recycled materials.
 
Boron said:
I saw this on another members post but lost the link? Maybe some knows?

We all know what a mess you can end up with, connecting all those cell volt little wires back to the BMS, so here's something so obvious and so much more tidy. What do you think? Laced connections (longer flexible busbars, or cable/ring terms?) From a mechanical view I find the hard connection using solid busbars puts stresses on the M6 studs and the sealing with the casing? Doesnt feel right. But those crimped multi-leaf versions are $$$. BTW this is what I use cos Im cheap. Its a copper tube wall clamp ca 10p ea. The csa is ca 3mm^2 so good for 50A, - my load max. Double up for 100A? Love your Plumber.
Click to expand...
Before getting into the question about whether the holes are the right size, I would make sure that even though it’s copper colored, it’s actually made of pure copper. First test can be done with a magnet. Second test would be to cut one in half and visually inspect it. Then I would try pushing some current through it and see how it responds.
 
It floats my boat and I measured the Res with a purpose Cell yr1035 meter - 0.2mohm. 50 A gives 0.5W heat - trivial effect give thermal mass of battery studs
@timselectric
Plumbing straps don't even come close. They are usually made from recycled materials.
So the csa is 3mm2 path length 50mm compare this with domestic cable wire. So do the math and then prove me wrong (I made a very close match)

@wpns
Before getting into the question about whether the holes are the right size, I would make sure that even though it’s copper colored, it’s actually made of pure copper. First test can be done with a magnet. Second test would be to cut one in half and visually inspect it. Then I would try pushing some current through it and see how it responds.

Been there and done all that, solid copper - no rusty magnetic pipe clips or CCA tricks allowed here heh heh
 
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It would be quicker than flattening a copper pipe and drilling holes on it but copper pipe is copper.
 
This reminds me of my old 24v lead acid bank. I had about 2 dozen old 31 series starter batteries that where pulled out of service after just one year. Got them for free. Actually, I still have them for a back up/auxilary system...

..anyway...I put a very small 10awg connecton between each 12v battery in series for the 24v nominal, about 2 inches long. The parrell bus bar was 1/4 x 1 copper bar directly wired to the thread terminals on the batteries. The goal was to "limit" the current that could go through any of the 12p2s batteries forcing others to help carry the burden. I couldn't afford any other protection mechanisms at the time.

The system worked amazing for 2 years. I didn't cycle them overnight but they where great for a between the cloud buffer. I eventually had shorted cells but no mega melt down to the limited current through the series of batteries. I have taken the bad ones out and 18 remain.

I had been thinking if this would work as a passive way to protect LFP cells...
 
sunsurfer said:
This reminds me of my old 24v lead acid bank. I had about 2 dozen old 31 series starter batteries that where pulled out of service after just one year. Got them for free. Actually, I still have them for a back up/auxilary system...

..anyway...I put a very small 10awg connecton between each 12v battery in series for the 24v nominal, about 2 inches long. The parrell bus bar was 1/4 x 1 copper bar directly wired to the thread terminals on the batteries. The goal was to "limit" the current that could go through any of the 12p2s batteries forcing others to help carry the burden. I couldn't afford any other protection mechanisms at the time.

The system worked amazing for 2 years. I didn't cycle them overnight but they where great for a between the cloud buffer. I eventually had shorted cells but no mega melt down to the limited current through the series of batteries. I have taken the bad ones out and 18 remain.

I had been thinking if this would work as a passive way to protect LFP cells...
Click to expand...
Sound agricultural approach for old lead cells but LAB thinking should be deprecated as LFBs are a different animal and if mistreated can have a much more destructive effect for many years onwards. A proper approach to fusible links and electrical connections is needed, slapdash methods and a careless approach to fire safety must not be encouraged - especially here. For example did you possess a proper pair of cable cutters permanently on hook nearby?
 
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