I normally build e-bike batteries and was interested to see if I can build a robust (for 300amps) 3 x 14s7p hooked up in parallel and then use them individually so I can use them for my e-bikes as well.
Here’s what I’ve found so far:
18650’s: https://www.evwest.com/catalog/product_info.php?products_id=484 - on sale for July2019 $630 for 200 of them!
3000mAh and 15A -> 30a peak up to 80c
connect them up with these: https://www.alibaba.com/product-detail/Customized-nickel-Welding-plate-copper-strip_60702294180.html?spm=a2700.7724838.2017115.272.27036ed3mDxJLX
Use copper terminal rings: https://www.aliexpress.com/item/32855498386.html
I use this to weld: https://malectrics.eu/product/diy-arduino-battery-spot-welder-prebuilt-kit-v3/
If I continue with this sport I’m going to attempt to build a 18650 battery.
Hope this helps someone