BQ27530-G1: Unable to Perform Calibration using Host System Calibration Method

Ravichandra T

Part Number: BQ27530-G1
Other Parts Discussed in Thread: EV2400, GPCCHEM

We are trying to communicate with the Fuel gauge using the i2c-tools and we are able successfully retrieve couple of properties from fuel gauge like current_now, voltage_now, device_id etc. But when we are reading the battery capacity, it always returns "0". To Calibrate the Fuel gauge using host System calibration method we referred Host System calibration but it doesn't seems to be working.

We followed the steps provided there,

Before executing the below commands, the CALMODE is being set, so we tried exiting the calibration mode, but it doesn't have any effect.

send_subCommand(0x00, 0x2D); //Enable Calibration mode
send_subCommand(0x00, 0x81); //Enter Calibration mode
send_subCommand(0x00, 0x00);
send_Command(0x00);
unsigned char buffer[2] = { 0x00, 0x00 };
_delay_cycles(10000);
I2C_read(buffer, 2);

So we are not very sure whether we are doing is right.

Are there any references w.r.t to i2c programming explaining how to send command and sub-command to the Fuel gauge?

8 months ago

0 Anthony Baldino 8 months ago

TI__Genius 13155 points

Hi Ravichandra,

Below is a example of how to use commands via I2C to change data flash parameters found in the bq27530 Technical Reference Manual:

/cfs-file/__key/communityserver-discussions-components-files/196/8037.bq27530_2D00_G1-SLUUA73-TRM-Draft-20Sept2013.pdf

Please let me know if this helps.

Regards,

Anthony Baldino

0 Ravichandra T 7 months ago in reply to Anthony Baldino

Prodigy 10 points

Hi Anthony,

Thanks for your input on Accessing the Data Flash. It helped a lot.

We tried updating the Design Capacity from 1544mAh to 2600mAh value using the above mentioned steps and it updated the Data flash Successfully. when we try reading the FullChargeCapacity() it is still returning the old value. Is our understanding right or Are we missing anything here?

0 Anthony Baldino 7 months ago in reply to Ravichandra T

TI__Genius 13155 points

Hi Ravichandra,

Can I ask why you are trying to increase your design capacity? This value is based on the battery you are using and should not be altered.

If you are changing the battery you are using, you will have to complete a new learning cycle with the correct chemID for the new battery.

Regards,

Anthony Baldino

0 Ravichandra T 7 months ago in reply to Anthony Baldino

Prodigy 10 points

Hi Anthony,

We are changing because we are using battery with a capacity of 2600mAh and 3000mAh battery for testing purposes.

Could you please give us more information about a new learning cycle? We are new to this.

Also, is it necessary to have EV2300 or EV2400 for obtaining/performing and calibration and obtaining a golden sample file?

0 Anthony Baldino 7 months ago in reply to Ravichandra T

TI__Genius 13155 points

Hi Ravichandra,

Typically when the calibration process is started, a learning cycle is completed so the gauge can take the full range of measurements for the Full Charge Capacity, State of Charge, State of Health, etc.

However, if you are switching batteries, then the measurements taken by the gauge will not be accurate for the new battery you are inserting due to the different parameters.

The learning cycle process requires the input of a ChemID, which is the battery profile of the battery you are planning to use. To figure out what chemID you need to use for each of these batteries, please refer to the GPCCHEM tool below:

https://www.ti.com/tool/GPCCHEM

The learning cycle is a produces a Golden Image file for the gauge, which contains all the parameters of that gauge and battery: