Im going to be building a new 10s4p battery from samsung 30q cells soon and I need some advice on how i would be able to safely connect the p-groups to a p-group pcb from duck battery systems. 18650 4p P-Group PCB – Duck Battery Systems (attached an image of what the board looks like if you dont wanna click on the link)
Im gunna be stacking two .10 nickel strips to make a .20 to form the p groups as my spot welder can only handle .10 max. I originally wanted to use p-group tabs but most are made .20mm thick and I cant weld that. Would using the stacked .10 strips and bending them onto the pcb be safe if i did it on all 4 corners of the p group? Or should i have 4 tabs that bend on the pcb on each side? Or is there an even better/safer way to connect them to the p-group pcbs?
Have You tried .15 nickel? I would solder the nickel to the pcb before spot welding the cells. it would be much easier if you could spot weld 0.2 nickel and ducky has pre cut/shaped 4p nickel.
You can always buy a spot welder that would do 0.2 and sell it for whatever loss you are prepared to have. Some of those cheap PCB options on Amazon are capable of 0.2 providing all the cabling is the right gauge, connections are solid and short wire lengths… I personally use 2 x 800A truck batteries connected in P for a total of 1600A and 280 Ah, with a Sequre SW1.
Connect the P groups with this type or copper braid. 2 Runs to be safe, although 4p on 18650 should never yield more than 60/70A actual peak load.
Ive tried 0.15 nickel with this soot welder Amazon.com but it struggles. Its a 50/50 on if it wants to weld or not so i figured just stacking 0.10 would be easier. I was looking into spot welders to connect to car batteries but for whatever god forsaken reason car batteries are expensive right now. And ive got 10 guage silicone wire handy would that be okay to connect the p groups together if i ran them twice?
The copper braid is cleaner as a solution as its flat so you can run wider gauge and carry more current. If you can get 8 gauge, then you can run 2 wires between the groups, less resistance and more headroom.Soldering should be done prior to spot welding the cells to avoid any excessive heat pumped into them. but for a 10s4p config on 18650 you will never have exorbitant current going through.
Those self contained ones are never too powerful. The solder probe wires are not thick enough, and the claimed output is never near. Try this one, with a good 800-950 CCA battery. You can probably find them for 60-70 bucks. in good shape.
I use 2 of these I got for 100 euro both . They had 6 months of little to no use. They retail for 240 euro a pop, so a good deal IMO. I run them in parallel
Having said 0.2 is ideal, you should, in the worst case scenario, be able to make good 0.15 welds…
On the p-Group connections; I use 3 short runs of this, a bit overkill, but spreads the load, and acts as failsafe should for some reason one of the solder joints come loose.
What I would do is do two layers of the nickel per side per cell. Then I would do one more layer of nickel over each side of the cells in order to help connect them in order to mitigate any uneven load distribution. It’s gonna take a good while but I think it’s the best bet if you want to ensure proper connections
i mean i cant spend 700$ on a battery either. im on a budget rn. i have everything i need from a previous build except a decent spot welder. its far cheaper for me to build a battery than it is for me to buy one. even if something fails i still wont break the bank.
