BQ34110: voltage and current calibration

Tejasweeni Zope

Part Number: BQ34110
Other Parts Discussed in Thread: BQSTUDIO

Hello TI,

I am using BQ34110 ic with STM32f4 series MCU. I am not using BQstudio software ,but i had done initial edits in some register using I2C commands which was instructed in document released by TI.

I am using two Li Ion batteries of 4.2V with 2200mAh specifications in series with my MCU board. my question is that,

1. As same current is flowing through both batteries , Do I need to perform current calibration? Can I keep default values of CC gain and CC delta for this setting?

2. When I tried to read design capacity with 0x3C, it gives correct answer, but with same code when I tried to get average raw voltage value using 0x7C, it is showing 0 everytime.

3. can you share values of CC delta, CC gain, voltage divider value(as max. voltage from battery should around 9000mV) with known force current of 500mA and known voltage applied =7040mv

over 5 years ago

0 Wyatt Keller over 5 years ago

TI__Guru** 105810 points

Hello Tejasweeni,

Once you perform the calibration you can use the golden image file to upload to your other boards to transfer the same calibration factors.

You should calibrate your setup for best accuracy, don't use the default calibration factors.

The avgRawVoltage is used for the calibration process, if you are looking for the voltage of your stack the Voltage() would be more accurate.

The CC delta and CC gain values would really depend on your system's setup.

Sincerely,

Wyatt Keller

0 Tejasweeni Zope over 5 years ago in reply to Wyatt Keller

Prodigy 120 points

Hi Wyatt,

Thank you for your quick reply.

First of all I am not using BQSTUDIO for calibration procedure.

When I tried to get value from Average Voltage (0x7C) in Voltage calibration, I did not get any value in response. hence could not complete voltage calibration.

From maximum pack voltage (which is 8.4V), I tried to put 9.33V value as new voltage divider value. from that I should get value nearer to my current pack voltage from voltage()(0x08/0x09) register but instead I am getting 12.336V.

0 Andy Liu (BMS) over 5 years ago in reply to Tejasweeni Zope

TI__Guru 52115 points

Did you follow the instructions mentioned in Chapter 5 of the BQ34110 TRM to do the calibration?

Andy

0 Tejasweeni Zope over 5 years ago in reply to Andy Liu (BMS)

Prodigy 120 points

YES sir.

I am getting value of other registers such as analog calibration counter(0x79), operation status(0x3A),design capacity(0x3C) correctly. Only AverageVoltage(0x7C) is not showing any value.

0 Kang Kang over 5 years ago in reply to Tejasweeni Zope

TI__Mastermind 24870 points

Hello Teja,

My recommendation to resolve this issue is as follows.

Use a logic analyzer and go through the bqStudio calibration using the EVM. Look at the I2C traffic there and then do the same thing on the MCU.

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BQ34110: voltage and current calibration