Just curious, how much current can the positive/negative traces carry?
that are just terminals they don’t have to carry much current…
Can u explain? If I draw 60a from those 30q cells they still pass through those terminals to whatever people use to connect them in series. 60a is 60a… I don’t understand what you mean when you say they don’t have to carry much current
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solder wire from batterys to terminal, and then a second wire right next to that point on the terminal (or in the picture above you could solder ontop of the spotweld)
Combine that green thing with this $$$
My next board has to be easier than IKEA furniture and Lego.
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Im planning to switch to these pcbs to make my batteries faster, and I plan to use JLCPCB to make them, I still need to figure out what settings to use I do not have any experience with this so any help would be nice I guess these are okay to carry 80A from a 4p pack? And to carry 120A I would need a 6 layer pcb? I removed the bms traces from the design btw
If you have any interest in buying a few for your pack just send me a pm, maybe even a small GB could happen.
anyone sell these already connected to cells?
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yessir, just select the P count in the options:
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Can u rivet a board or get some terminals put on so you could screw down connections. Any solderless ways. A through hole you could wind through maybe would be good. Could do some resistance test. Hope to get some soon.
OR MAYBE JUST RUN THE WIRE OVER THE TOP AND HOT GLUE IT! im definitely doing resistance tests doing that.
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this is it. These have wide copper two ounce strips, double-decided, with a solder cover on the bottom. meant to be welded to and soldered at the ends to the other pcb and escs.
if you want to get some of this first test batch im ordering its 20$ for the two and you do the spot welding yourself.
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I have to try this conductive copper tape. The supposedly conductive sticky part is amazingly sticky. Ironically it seems safer without the positive side donut attached and it holds better bare. All in all all though this may look flimsy it’s very solid. This pcb was a mistake at 67mm wide instead of 65 so the tape isn’t as secure here as will be when the 65mm pcbs show that are coming.
How to test the conductive addhesive? I want to do a conductivity test somehow. If it takes twenty amps for five min straight and I can still touch it I’m sold. Doubt it will. I only have a ten amp supply and can split the copper strip or would that be too low a resistance or something for the supply and break itt? 
I’ll tear it down to bare cells after riding it and look for wear. If the solder mask on the pcb can take some rubbing from the cell, which I expect it should and not rub through to the copper but other than that…having been playing with this tape and now on the board I think physically it could be reliable and at worst if it did break, with the tape stuck so well it is unlikely to short through the pack. But you could maybe push the tape into the positive tab down to the negative. Unlikely. assuming it shows good enough with conductivity and continuous heat put on the glue I’ll put them to the real test. I think a glue connection maybe isn’t possible with cycling of heat and hoping for way too much
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I had a look at a datasheet for one of the best copper foil tapes I could find, 3M 1182: https://www.tedpella.com/technote_html/16074%20TN.pdf
The resistance through a 1 inch square adhesive is 0.01 Ohm according to them. On the cell you have roughly a 15mm circlular contact area, and in that case there is 3.65 times less contact, or 3.65 times higher resistance, so about 0.036 Ohm. At a conservative 10 A per cell, there would be 3.6 W of heat lost in the adhesive, which is a huge amount for that small area and it will definitely heat up instantly to over the spec.
It is a nice idea but it doesn’t seem like it will work. These foil tapes are mainly meant for shielding, not power transmission.
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I was thinking to build parallel PCB battery modules with XT30 connectors to handle the current from one to another in the near future. Basically something like this:
In this case the end user would not have to solder at all. Also don’t have that in the diagram, but the balancing would be done with a JST 1 pin connector to each module going to a balancing connector. Also would need an XT30 extension for the middle of the pack, and an 2x XT30 to XT90 adapter for the positive and negative terminals of the battery.
There would be some length lost due to the protruding tabs, but that drawing is not to scale and they should be easy to make pretty small, about 8-9 mm of space between each module.
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Here is a very quick rough CAD model of my idea, with accurate scale. The wires would have more slack than in these pics:
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Xt30 are pretty small but there’s thousands of connectors out there even smaller. It’s appealing to take them apart to be plane legal with just the four cell groups but I broke from that goal with using the two long pcbs
With the tape it could’ve been broken down easily but the adhesive in this tape is hugely resistant and not usable for any substantial current. The copper strip width and thickness is good enough and I’ll try spot welding this tape. .06mm I think it is.
The nickel is .2mm and 8mm wide. the cell is solidly connected to the pcb. The copper in background was too finicky to weld probably because of the adhesive and when it does work it doesn’t make the strong structure the nickel does
And a cell with a hole from doing the copper with adhesive. And my keys maybe I’ll crank up the settings and make the monokey
I ordered the correct 65mm pcbs and with a chamfered edge but otherwise the same. If u want these 67mm ones take them for 5$ each plus shipping
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This looks amazing! You should definitely take it forward. Post it on the no words thread.
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Hummie, please consider soldering the tab to the pcb. If you have a high wattage soldering iron that will work the best.