Why it is not that smart to passive balance LiFePO4 cells even though they are matched and why top balancing works. In this video I show what went wrong in my last video [ Ссылка ] when I tried to passive balance cells.
More Information about what and where I bought stuff: [ Ссылка ]
I recently got 4x CALB 120Ah prismatic aluminum cells, and they all were in a range of 10mV, so I just connected them in parallel and put them into series after two days of "passive" balancing when all cells were on 3.27V.
After pushing 80Ah to the battery pack (in series) the BMS high voltage protection kicked in as one cell went up to 3.7V. The others were at around 3.31 at this point in time, so the pack was definitely not fully charged. What was the problem?
Chapters
00:00 Intro
00:38 Passive balancing of LiFePO4 fails
01:50 Debugging the problem of passive blancing
02:50 Top balacing LiFePO4 cells
03:20 Why passive balancing does not work for LiFePO4
07:15 Self reflection, what was my problem
08:14 Summary
09:08 Outro
