BQ3050EVM-001: BAT Charge Algorithm

bhupendra suthar

Part Number: BQ3050EVM-001
Other Parts Discussed in Thread: BQ3050, TCA9548A

Hello Team,

Does BQ3050 and its series IC`s have inbuilt charge algorithm ? When the Battery RSOC is around 5% , even we charging current of 800mA but Battery takes on around 400mA of charging current.

We did not find any such Algorithum on TRM of BQ3050.

Smart Battery is of : 14.8V / 6.9Ah

From Charger Side we are setting CC/current this way:

if((BQ2_RSOC <= 10) && (BQ2_RSOC >= 0))
Set_Chg2_VoltageCurrent(16800,800);

if((BQ2_RSOC <= 75) && (BQ2_RSOC > 10))
Set_Chg2_VoltageCurrent(16800,1600);

if((BQ2_RSOC <= 90) && (BQ2_RSOC > 75))
Set_Chg2_VoltageCurrent(16800,1400);

if((BQ2_RSOC < 99) && (BQ2_RSOC > 90))
Set_Chg2_VoltageCurrent(16800,800);

- Regards

over 2 years ago

0 Jose Couso over 2 years ago

TI__Mastermind 25946 points

Hello,

The bq3050 has a Charge Control SMBus Broadcasts section located at C.7 in TRM

ChargingVoltage and ChargingCurrent broadcasts are sent to the Smart-Charger device address (0x12) every 10 to 60 seconds.

Regards,
Jose Couso

0 bhupendra suthar over 2 years ago in reply to Jose Couso

Intellectual 455 points

Yes , Jose

I am aware of that.

Question is : I am not setting charging current and voltage received over SMbus. Charger sets current as per values provided by Host MCU. In my case it is 800mA. But still BMS draws only 400mA, why ?

0 Jose Couso over 2 years ago in reply to bhupendra suthar

TI__Mastermind 25946 points

Hello Bhupendra,

If you have broadcast mode setup for the bq3050, the gauge may just re-write the value you write with the host.

Also, how are you making sure the communication between the host and gauge is working properly? The driver may not be good and nothing is being written properly.

Regards,
Jose Couso

0 bhupendra suthar over 2 years ago in reply to Jose Couso

Intellectual 455 points

Ok, but why Guage is writing 400mA to charger ?

we have not set 400mA value in any of guage Register. See below snap.

0 Jose Couso over 2 years ago in reply to bhupendra suthar

TI__Mastermind 25946 points

Hello Bhupendra,

You mentioned "I am not setting charging current and voltage received over SMbus. Charger sets current as per values provided by Host MCU"

It seems like this is not a gauge issue, the issue might be coming from how you are setting the current from the host (MCU). I would first start from there, and check communications are working as expected.

Regards,
Jose Couso

0 bhupendra suthar over 2 years ago in reply to Jose Couso

Intellectual 455 points

Hello Jose,

I am not setting charging current and voltage received over SMbus. Charger sets current as per values provided by Host MCU"

Point is I am not using any voltage and current values received from guage over SMbus. I am setting my own current and voltage to charger ( Smbus based ) using Host.

SMbus works fine. I am able to read all SBS parameter from guage correctly..

0 Jose Couso over 2 years ago in reply to bhupendra suthar

TI__Mastermind 25946 points

Hello Bhupendra,

What type of charger are you using? Is it a TI's charger?

Regards,
Jose Couso

0 bhupendra suthar over 2 years ago in reply to Jose Couso

Intellectual 455 points

Charger IC is LTC4100 from ADI. Voltage and current values set by MCU on SMbus.

I2C Lines for charger and BMS are separate using I2C Switch , TCA9548A.

All I want to know is Does BMS IC (BQ3050) can control the charge current even supplied current is higher considering battery low RSOC ?

I see Charging Algorithm word on BQ TRM.

0 Jose Couso over 2 years ago in reply to bhupendra suthar

TI__Mastermind 25946 points

Hello Bhupendra,

First, I would make sure broadcast mode is OFF since you are not using this feature.

As for the charger you are using, this is not a TI's charger so I can't help you on that.

All I want to know is Does BMS IC (BQ3050) can control the charge current even supplied current is higher considering battery low RSOC ?

Charge Current and Charge Voltage will be reported regardless of RSOC value.

I also see you are using your own logic to implement a charging algorithm, please ensure your logic is implemented correctly, this is not something we can help you with.

Regards,
Jose Couso

0 bhupendra suthar over 2 years ago in reply to Jose Couso

Intellectual 455 points

Hello jose,

I am Pointing out this :

I need to broadcast Alarmwarning so can not disable BCAST bit. I just want to disable voltage and current value Transmission from guage.

0 Jose Couso over 2 years ago in reply to bhupendra suthar

TI__Mastermind 25946 points

Hello Bhupendra,

The BCAST bit has to be disabled in order stop transmission for ChargingCurrent and ChargingVoltage. Disabling the BCAST will cause the AlarmWarning broadcast to not work.

Unfortunately, there's no work around for this situation.

Regards,
Jose Couso

Power management

Power management forum

BQ3050EVM-001: BAT Charge Algorithm