The 4S pack I built previously works fine but I have lost my ability to charge at work, so I need a pack that will allow a round trip, which is 15 miles with hills and lots of stops. The riding I do uses about 44.4Wh/mile. This meant that the 10Ah pack would get me to work and then die about 1/2 way home.
Samsung says 20A continuous from thes 25R cells which would mean the pack could max out at 160A, but the highest I have seen from my motor / controller is less than 4000 watts, which is pretty close to 80A, so the 80A BMS should be fine.
I'm building a 20AH 48V battery pack using:
* 96 Samsung 25R 18650 batteries
* A generic 80A 12S LiPo BMS
* 12 of these Agniusm 8P battery modules
I now have the batteries in the packs and have made the copper interconnects and assembled it all into a pack. I'm going to make a plastic box to house it in.
Pack size is 3" x 10 5/8" x 7" high.
Batteries were around $400, the battery modules were around $170, and the BMS was around $75, so about $645 total. That's about the same price that you can get a pre-built spot welded pack for. The advantage of this pack is that I can easily replace the cells if any of them go bad or if someday I want to use a different cell.
I find it amazing that almost 10 years ago my 20Ah "48V" Ping LiFePo4 battery that cost about the same amount was over twice as heavy, over twice as large, and only able to deliver about 20A.