I’m starting to build my first battery pack from 21700 batteries and I have a few questions about connecting them together.
I’ll use 0.2mm x 10mm pure nickel strip to connect the cells to 0.5mm copper.
What do you think about this design?
I’d first spot weld the strips to cells that are overlapped by copper and fold them over copper.
Would there be any difference if I do it like that:
and then solder nickel strips to copper and cells?
Is there any real benefit at this design other than heat dissipation?
Nickel strip 0.15 between cells are good , best making fused type connection even if soldering cells is not a good IDEA at all
Nickel strip between cells are working because even it is high IR then copper the short length make it ok to run cells to full discharge rate with not much or not heat and voltage sag
So adding cooper won’t make it better even worse it case of short cut
Copper is only necessary on bus bar
I tried spot solder copper on soldered strip nickel plate : it is working , not strong but working , if you pre solder nickel strip , spot them on cells then spot copper plate on it you get what you want but it is not necessary to me
With a different configuration you could just use nickel strips like these:
US $5.25 11％ Off | High purity 21700 Pure Nickel Strip 2P 0.15/0.2*27.5mm for battery spot welding ,21700 Li battery nickel tape spot welder
Just built 2 6S8P batteries from 21700. Used 0.2x27.5mm nickel strips and 8 AWG wires at the terminals. They work great so far: Daniels (un)geared inflatable (slowly built) - #56 by sat_be
I understand what you’re saying but let’s assume 13s10p offset is the only option.
Should work as well. 10 in a row for the P, then 13 rows for S with the suggested strips (without terminal rows, first and last). Measurements L and W will be slightely different, as the offset would be in a different orientation.
Forgot to mention the spacers, they are recommended to isolate the rows, as the cans have different potentials.
US $4.55 5％ Off | 10pcs/lot 21700 Battery Holder Bracket ABS Plastic 20 Cells 10S2P Battery Spacer Expandable Battery Holder
Sorry for not clarifying earlier. 10p should be zig-zag.
The size of a compartment is limited.
OK, I see, then you need zigzag strips, not sure if they exist for 21700.