Doctorbass wrote:Ypedal wrote:agreed, to a point.. these cells remain ballanced very well, but by grouping P groups first, then series those you can monitor the voltage of each group as a single display. instead of each string seperately.. if you care to monitor.. and you should..
Yes.. i'm i the group of person who preffer PARALLEL FIRST and than serie...
This was debated alot and John, in the industrie you will NEVER find any "serie first and than parallel"
Too many seperate induvidual cell without any monitoring!!
Only LiMn and nicad MUST be done the way you suggest due to the particular chemistry.
For those who want to parallel each level it's still less than half the work if you don't take them apart. Plus you only need to solder the parallel connection where the tab is at the negative cell end, so you don't risk melting or weakening the plastic protector at the positive end. I cringe when I see people break these packs into individual cells, because I know the work that they've created for themselves, along with the cell matching they've lost. You don't break up the 2p V packs, so why do it for the 1p VT packs?
As far as monitoring at the cell level, it's not done on hundreds of millions of lead acid car batteries, and these LiMN cells self balance through the same mechanism, so I don't see much point unless you're running your pack at stressful levels.
A required step not mentioned though is capacity matching.
FWIW, the 2000+ Konion cells that I've built into packs for myself and others haven't had a single failure. Some of those packs are over 1k cycles, including those on my daily rider that has seen 2 cycles on a typical day for over 2.5 years, so dismissing my easy build build method as incorrect is unwarranted based on real world results. If pack building was really as hard as some make it, then I wouldn't even build my own packs. These cells don't burst into flames like Lipo, so there's no real risk building them in a less than technically ideal manner, and the time I save is worth more than the pack itself.