6s LiPo pack (6x18650) was measured few minutes before finishing balanced charging. (At the end total unbalance became 4,20V +/- 0.07V, max 4,208, min 4,196V). Parallel with cells is Chargery BM6 cell monitor. LiPo charger is chinese clone named "Mystery", which is upgraded
* with fan against overheating
* all 6 cells balancing resistors got new values, to get result 4,20V +/- 0,01V
* total voltage measuring resistors got new values also.
Idea, what resistors need changing, is taken from schematic on russian RC site (zip file):
http://forum.rcdesign.ru/f8/thread59625-26.html#post1281423
Fom russian schematics you must find these balancing accuracy resistors:
I cell - R61-R63
II cell - R72-R74
III cell - R143-R145
IV cell - R100-R102
V cell - R138-R140
VI cell - R95-R97
total voltage- R65-R67
Then you must find the same resistors in your Mystery charger (PS. all cell balancing resistors in Mystery are alone, not 3 pieces serial, as on the russian schematics) I can`t give exact resistor numbers, because there are more than 3 different Mystery schematics.
As you see result, no overcharging or disbalance after üpgrade.
I changed resistors after measuring total and balancing voltage per cell. Resistors I modified:
total voltage R56 - 200K, R27 - 18,270K
balancing voltage
zero cell R97 100K, R98 100K
1st cell R95 100K, R96 100,470K
2nd cell R76 200K, R77 200, 680K
3rd cell R75 499K, R41 249, 910K
4th cell R46 499K, R71 249,820K
5th cell R44 499K, R41 249,750K
6th cell R42 499K, R40 - 251K
Picture shows modified R72 and R71
Ventilation 2mm holes were drilled also
http://keep4u.ru/full/470029955e6886c5d81149ae5563d499.html
