BQ34Z100EVM: Need assistance in setting up the BQ34Z100-G1 for first usage

Shrey Kalra

Part Number: BQ34Z100EVM
Other Parts Discussed in Thread: BQSTUDIO, BQ34Z100-G1, EV2400, GPCCHEM, BQ40Z50

Hello,

We are using the BQ34Z100-G1 evaluation board as a fuel gauge for feasibility studies of battery cells in a research project. After having having set up the board and BQStudio (via EV2400) I am able to read register values as reported by the gauge, the I2C comm. works well, and have also set the data parameters as per the battery cells after reading the data-sheet/user guides.

I am quite a new user of any of your EVMs/ICs. So now, from my understanding the next steps are to :

Firstly, Calibrate the gauge (current and voltage mainly as stated in the guide)
Then ,Carry out a charge/discharge/rest to program the CHEM ID (following this)
Finally Carry out a learning cycle for the gauge to read correct values

Is this correct & also a Necessary approach? Before I star to read reliable values? (Since, right now the voltage/SOC/current vary greatly as soon as I attach a load to BAT+,PACK-)

If yes, there are a few questions:

Before going to steps 2 and 3 I must calibrate the gauge. I followed the steps (okay for voltage etc.) but I am unable to calibrate the current before proceeding. It always shows a ~500mA offset from zero even after calibration to -1000mA repeatedly
The GPC tool is a must to use? or can i select a battery from the given list of chemistries (what is recommended?). Is the CHEM ID determination based on 1 cell or whole battery (say 2S or 3S)?
After chem id programming the learning cycle is to be done only ONCE or multiple times? What if we need to switch between (1S, 2S, 3S etc.) must we do multiple learning cycles for each? Can these cycles be saved so we can do tests faster and keep switching the batteries?

I have have subsequent questions to move ahead. I would appreciate some help in getting the gauge up and running. Thanks !

Best Regards,

Shrey KALRA
Research Assoc.
MAE (NTU) Singapore

over 5 years ago

0 Matt Sunna over 5 years ago

TI__Guru* 81035 points

Hi Shrey,

There is a video on calibrating the current for this device that might be helpful: https://www.youtube.com/watch?v=UnwkqdlUxpc

For the ChemID, you can select your battery chemistry if it is already in the database. If you cannot find a match and need to use the GPCCHEM tool to find the closest match, you only need to run the process on 1 cell.

I think you would need to run a different learning cycle if you change the number of cells configured (the capacity changes). You can save a golden file for each configuration. This video for the BQ40Z50 gives some great guidance on running the learning cycle and creating a golden file: https://training.ti.com/bq40z50-setup-and-going-production

Best regards,

Matt

0 Shrey Kalra over 5 years ago in reply to Matt Sunna

Intellectual 320 points

Hi Matt,

Thanks for references, I shall check them out. But before I proceed to do those steps, I do need to properly calibrate the gauge right? This I have elaborated in my point number 1. Could you suggest a solution to that problem, since I cannot find any even reading through the e2e forums or following all the steps in guide correctly.

Thanks,

Shrey

0 Matt Sunna over 5 years ago in reply to Shrey Kalra

TI__Guru* 81035 points

Shrey,

The first link I sent is a video specifically about calibrating the current on the BQ34Z100-G1.

Matt

0 Shrey Kalra over 5 years ago in reply to Matt Sunna

Intellectual 320 points

Yes Matt thanks for the links,

I have gone through the video multiple times and followed the process several times. I am still unable to get rid of the current calibration offset (as I explained) never getting to a zero-zero (or even close). What do you think could be causing this ?

Best,

Shrey

0 Matt Sunna over 5 years ago in reply to Shrey Kalra

TI__Guru* 81035 points

Hi Shrey,

It seems like something must not be connected correctly if you are seeing such a large current on your board or the data in calibration memory is not good.

Make sure your connections to the EVM are following what is shown in the EVM User Guide and video. Make sure your jumper settings are correct.
Be sure to calibrate voltage first before calibrating current.
It might be good to reprogram the firmware back to factory defaults. The device firmware can be downloaded from here: https://www.ti.com/lit/zip/sluc580
If you are still not able to resolve this problem, there is always the possibility that the EVM is bad or damaged. You may want to check into getting the EVM replaced.

Here is another thread where it looks like someone saw a similar problem:

https://e2e.ti.com/support/power-management/f/196/t/515619?BQ34Z100-G1-current-calibration-problem

Best regards,

Matt

0 Shrey Kalra over 5 years ago in reply to Matt Sunna

Intellectual 320 points

Hi Matt,

Thanks for the advice, after trying everything else resetting the firmware back to factory default fixed the issue with current calibration offset.

I shall proceed to steps 2 and 3 for the ChemID and Learning cycle and get back to you on here again.

Best,

Shrey

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BQ34Z100EVM: Need assistance in setting up the BQ34Z100-G1 for first usage