Hi Criton,

BQ79758-Q1 does not support active cell balancing; it supports passive cell balancing. At this time, my team does not have a monitor in our portfolio that supports active cell balancing.

Instead of using the BQ76PL455A-Q1 (16S, 2nd generation monitor), we would encourage you to evaluate the BQ79616-Q1 (16S, 4th generation, does not require NDA for evaluation) or BQ79718V-Q1 (18S, 5th generation, requires NDA for evaluation/discussions). These 2x devices (without current sense) I have recommended have improvements upon BQ76PL455A-Q1, which includes additional features, more robust communication, and tightened measurement accuracy. 

If you are interested in a monitor that includes current sense, we would encourage you to evaluate either BQ79656-Q1 (16S, 4th gen, does not require NDA for evaluation) or BQ79758-Q1 (18S, 5th gen, requires NDA for evaluation). 

Please find a reference design that I located: https://www.ti.com/lit/ug/tidubz7/tidubz7.pdf?ts=1727187762111&ref_url=https%253A%252F%252Fwww.ti.com%252Fsitesearch%252Fen-us%252Fdocs%252Funiversalsearch.tsp%253FlangPref%253Den-US%2526nr%253D4403%2526searchTerm%253Dactive+cell+balancing 

In addition, please find this E2E thread posted by one of my colleagues that mentions cell-balancing topics. It may be useful for your understanding and provide additional learning resources: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1371288/bq76972-bq76972-bjt-cell-balancing-and-active-cell-balancing?keyMatch=active%20cell%20balancing&tisearch=universal_search 

Best Regards,

Julia Louis

Hi Julia Louis,

Many thanks for the detailed information.

Kind regards,
Criton

Hi Julia,

I was going through the datasheet of BQ79656-Q1; Correct me if I am wrong, I found that it does not have integrated charge pumps and other dedicated pins for connecting the CHG and DCHG MOSFETS. How should be the Charge and discharge MOSFETS be connected on the high side using BQ79656-Q1? Should I integrate an additional Battery protector IC and FET driver to the BQ79656-Q1? I look forward to hearing from you.

Many thanks and Kind regards,
Criton 

Hi Criton,

Sorry for the delay, the E2E was reassigned to me. I believe there is a mistake with the attached schematic. The part shown is a BQ76952. Is this intentional?

Best,

Zachary

Hi Zachary,

Many thanks for getting in touch. This image was intentional as I wanted to show and ask you how I can connect BQ79656-Q1 to the discharge load and the charging path to the battery. if you see BQ76952 there are dedicated pins for the discharge MOSFETS and charge MOSFETS and integrated driver to drive them. Correct me if I am wrong, from my understanding the BQ79656-Q1 can only discharge to the cells to balance them right? and my question is how it can be connected to the load and charge path?

I look forward to hearing from you.

Kind regards,
Criton 

Hi Criton,

The BQ76952 has these pins for charging and discharging the pack. Our part does not have this functionality. If you would like our part to be able to do something similar, you would need to use, for example, the GPIO pins to control external FETS, if you would like to explore the option of developing external circuitry. 

Best,

Zachary

Hi Zachary Balov,

Thank you for the response. I will explore the options with BQ76952 and revert if I have any queries.

Kind regards,
Criton