need help building battery

[bread]

coming from a background of motorized bikes i wanted to join the e-bike world so I'm currently building an e-bike on an enduro ebike frame, I'm using a 5000watt qs205 v3 with a 150a sabvoton controller. I'm thinking of using Samsung 40t 21700 cells in the battery in a 20s10p configuration, mainly because they are on sale for $4 a cell new but also because they seem really high discharge and capacity, this should lead to a 40ah battery with 72v at 350a. now my question is, do the Nickle strips need to handle all 350 amps if the controller can only draw a max of 150? and what about the BMS, do I need a BMS that can handle the full 350a? honestly, any advice about anything is appreciated because my knowledge is extremely limited. If you have a different cell recommendation or any thoughts just let me know.

 

[SlowCo]

Look here: https://endless-sphere.com/forums/viewtopic.php?f=14&t=69683
The links in the third post will give you all the info you need. Good luck and be cautious!

 

[bread]

I've already got most of the parts for a battery im building for an enduro e-bike style build. looking for some advice on the battery pack design, I've gone for a 20s 9p design with molicel p42a cells, I already have the cells, and a 500a peak 240a continuous smart ant BMS. I've attached an image of my current plan. Since it's going to be folded so its 3 cells long, 6 cells wide, and 10 cells high, the yellow pieces in the picture is the copper I'm using to connect the cells together, I've kinda confused myself here on how I'm going to connect the three packs together because the way I have it drawn out now there will be a really long copper sheet between the pack's. and how do I connect the BMS wires and discharge leads, I've seen people on youtube use solid core wire twisted together and solder around on the positive and negative ends, I'm kinda just confused in general at the moment. any advice at all would be appreciated. or if there are any online resources you think I would benefit from feel free to direct me to them.

 

[LewTwo]

Just a thought: Could you cut the copper sheets along the fold lines (blue lines) and then join them together with soldered copper-braid (gray lines) ... length to be determined?

 

[bread]

while that isn't a bad idea I actually came up with something else, now I'm wondering how the copper is going to handle that much current. I have .1mm copper and .2mm copper, I tried welding with the .2 and it didn't make strong welds, so I'm going to use a .1mm copper but I don't think that .1mm copper alone is enough to deliver the full 150 amps. any ideas?

 

[LewTwo]

I don't think that .1mm copper alone is enough to deliver the full 150 amps. any ideas?

If you are using 21700 cells then those plates apear to be 3 cell wide or 63 mm
63 mm × 0.1 mm = 6.3 sq mm
That is somewhere between the equivalent of 9 to 10 AWG wire.
Actually what you want to look at is the capacity in watts but the real question is how far it it is carrying that power.

Finding DC current capacity ratings for a given size wire is sometimes challenging.
See this page:
https://dcthermal.com/wire-guidecharts/
However you will have to extrapolate the answer to your question because the maximum value given by the charts is 50 Amps at 72 Volts (3600 watts) for 13.8 foot long 10 AWG wire.