BQ76952: Autonomous Cell Balancing issue

MounishPatel Seetha

Part Number: BQ76952

Hi,

Previously I used shunt resistors on PCB and activated Autonomous Balancing, But Now I am using a Hall Probe sensor and stacked multiple bq76952 devices. Autonomous balancing is previously turned on during charge process but now how should i inform BQ76952 that charge is happening so Autonomous balancing can be activated ..

over 2 years ago

0 Matt Sunna over 2 years ago

TI__Guru* 81034 points

Hi Mounish,

Maybe in this case it would be easier for the host to control the balancing if there is not a way provided for the BQ76952 to see that charging is taking place. Or you can enable Cell Balancing in relax mode if that is okay for your system (set the CB_RLX) bit.

Best regards,

Matt

0 MounishPatel Seetha over 2 years ago in reply to Matt Sunna

Intellectual 795 points

Hi Matt,

is there a way to tell bq76952 that charging is going or is it just voltage drop on shunt?

0 Matt Sunna over 2 years ago in reply to MounishPatel Seetha

TI__Guru* 81034 points

Yes, it is the SRP/SRN pin measurements that determine if charging is taking place.

0 MounishPatel Seetha over 2 years ago in reply to Matt Sunna

Intellectual 795 points

Do you think is there a way to tell that charging is going on without using those pins? or how to direct those pins to tell charging is going on?

+1 Matt Sunna over 2 years ago in reply to MounishPatel Seetha

TI__Guru* 81034 points

Hi Mounish,

No, SRP/SRN are the current sense pins and are needed for the BQ76952 to know whether charge or discharge is occurring.

Other users have used Hall sensors in the past to interface with SRP/SRN on other devices. See the below thread for example. However, I do not have any direct guidance for how to implement this.

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/730105/bq76930-hall-effect-current-sensor-connection---srn-or-srp

Best regards,

Matt

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BQ76952: Autonomous Cell Balancing issue