BQ28Z610: Problem after new chemistry.

Boris Ivashinnikov

Part Number: BQ28Z610

I have a problem with measuring the charging status of a battery in charging or discharging time.
Our company made characterization of our battery via TI(e2e.ti.com/.../811822 after that we got chemistry for our battery.
It solved some problems but now if we write new chemistry in BQ28Z610, our devices in discharging turn off after 30-20% and don't reach 100% in charge. Can anyone help with advice on how to fix this?

over 4 years ago

0 Nick Brylski over 4 years ago

TI__Mastermind 19195 points

Hi Boris,

Have you completed a learning cycle? This is required for best performance.

Best,

0 Boris Ivashinnikov over 4 years ago in reply to Nick Brylski

Prodigy 60 points

Hello Nick!

Yes, we completed a learning cycle. Did we need to do any additional reset procedures in the BQ28Z610 before the learning cycle?

0 Kang Kang over 4 years ago in reply to Boris Ivashinnikov

TI__Mastermind 24870 points

Hello Boris,

Make sure the update status is 0x06 or 0x0E.

Make sure the charge termination conditions are set appropriately according to VCT in the TRM.

Thanks!

0 Boris Ivashinnikov over 4 years ago in reply to Kang Kang

Prodigy 60 points

I checked it out. The update status is 0x0E.

We have a problem with the VCT flag that is not being set. We think this is due to the balance of the cells. We made a balancing setting, but we have a difference between the cells of 10-20 mV at the end of charging.

0 Nick Brylski over 4 years ago in reply to Boris Ivashinnikov

TI__Mastermind 19195 points

Hi Boris,

What do you have the charge taper current set to? VCT requires two consecutive 40-s periods when AverageCurrent() < Charge Term Taper current. If it is close to Quit Current threshold(10mA), it enters Relax mode before meeting the timing condition.

Best,

0 Boris Ivashinnikov over 4 years ago in reply to Nick Brylski

Prodigy 60 points

Hi Nick,

Yes, We set it.
Problem with 99% charge is not a big problem.
We don't understand why devices disable when the charge is 30-10% in discharging. It happens with new chemistry.

0 Wyatt Keller over 4 years ago in reply to Boris Ivashinnikov

TI__Guru** 105590 points

Hello Boris,

When you say turn off do you mean the FETs are disabled or the gauge enters a shutdown mode? Could you share the log of the test when this event is happening along with a .gg file?

Sincerely,

Wyatt Keller