BQ40Z50-R2: cell balancing issues

Eeswari Patibandla

Part Number: BQ40Z50-R2

hello,

During charging, iam unable to charge cell 4 to 3.65 v ,i am seeing cell 4 bal_dod at 744 and all other at 0.Help me to enable cell balancing for cell 4,cell 4 balance time is at zero .

Best Regards,

Eeswari.

learn charge cb.log cell 4 not balancing.gg.csv

over 4 years ago

0 Eeswari Patibandla over 4 years ago

Intellectual 375 points

please go through this thread i am facing same issue

here it is for cell 1 i am facing issue for cell 4(balancing) i am reaching 100% soc

here

0 Wyatt Keller over 4 years ago in reply to Eeswari Patibandla

TI__Guru** 105640 points

Hello Eeswari,

It looks like when the cells relax they relax around the same voltage. Do you have any large resistance between the cells, specifically cell 4 that would cause the cells to be that out of balance during charge? (200mV difference).

Sincerely,

Wyatt Keller

0 Eeswari Patibandla over 4 years ago in reply to Wyatt Keller

Intellectual 375 points

hello keller,

i am using only internal balancing circuit (10 mA max) for all cells ,no any special resistor for cell4 , all balancing resistors are of 100 ohm

can you please provide assistance to resolve the issue fast.

Best Regards,

Eeswari.12v,20Ah-charge 4.5A.log 12v.gg.csv

0 Wyatt Keller over 4 years ago in reply to Eeswari Patibandla

TI__Guru** 105640 points

Hello Eeswari,

The CB time is based on capacity delta calculated between cells, if you have high capacity cells, this will make the CB time be very large if you are only using internal cell balancing of the gauge. If the cells are becoming that unbalanced I would make sure all the connections are good, your cells shouldn't be getting that out of balance.

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ40Z50-R2: cell balancing issues