Hi! In this video I have 3 no longer used 48v battery packs that I did not want just sitting and wasting away, and so I assemble them together into a single 72v battery pack. It is 20 series and 8 parallel which equals 84v28Ah full capacity. I disassembled the 48v battery packs and checked each individual cell and charged them to a 4.1-4.2 range as well. This was not shown but is very important. There were batteries that did not measure this at full charge and so I did not use them.
Batteries in parallel are all faced the same way positive and negative side by side. So I had groups of 8 18650 batteries all facing the same way.
Batteries in series are alternating when put side by side. I had 20 groups of 8 batteries in parallel, so it was one row of positive next to a whole row facing negative. Spot welding the nickel strips also alternates when you turn the battery over you don't want to be welding the same two rows! Rather the two rows you had not joined.
Finally I added a 72v 60a bms that I bought from Amazon where P- and + was my main discharge that I used a XT90 for. The C- and + connected to charge which I had used a EC5 connector for. Due to the discharge whenever these make contact it's important to use something like these as they keep controlled the big spark that's made.
This video is meant more for entertainment rather than something like a tutorial because of how much I just did not care! Obviously this is completely irresponsible and dangerous for example the using of a knife to take the nickel strips off. I'd suggest everyone else adhere strictly to proper procedures and safety measures, seriously. There were many instances where it could have turned into a much worse situation. I learned from this experience and plan to repeat this process one more time and upload a more carefully and properly done video.
By the way I made the music in this video also! I will do so for all future videos and I hope my skills improve and the quality as well.
