BQ34Z100-R2: BQ34Z100-R2

Jason Tedford

Part Number: BQ34Z100-R2
Other Parts Discussed in Thread: BQSTUDIO, BQ76942EVM, BQ34Z100EVM, GPCCHEM

Tool/software:

State of Charge is only accurate during the charge cycle. Remains at 100% when I discharge the battery.

1) I'm using 3 Lithium Polymer batteries from MOTOMA. (No Chem files available but 3.7V 3400mAh) They are connected as a Pac on a BQ76942EVM but I've bypassed all the FETS on that board to test the BQ34Z11xxEVM board. The Power supply is connected to BAT+ and PACK- and the electronic load is connected to BAT+ and BAT-. I've entered the FCC value of 12600mV, the number of cells (3) and set the VOLSEL bit. I've calibrated the Voltage and the Current and BqStudio accurately displays the voltage and the Average current during charging. Also, during charging the SOC is correct and the WAKE button illuminates the LEDs correctly. However, when I disconnect the charger and apply a load the Average Current goes to zero and the SOC remains at 100%. I've cycled this several times. I'm sure this is user errro but any insight would e appreciated.

default_fuelgauge_10mOhm.gg.gg.csv

11 months ago

0 Diego 11 months ago

TI__Mastermind 26605 points

Hi,

When you discharge is the current reading a negative value? Is only avg. current wrong or both? Can you share a schematic?

Regards,

Diego

0 Jason Tedford 11 months ago in reply to Diego

Prodigy 40 points

The Average current is positive. The schematic is in the EVM guide. Please see the Charging and Discharging screen captures from Bqstudio:

0 Diego 11 months ago in reply to Jason Tedford

TI__Mastermind 26605 points

Hi,

Understood, you are using the BQ34z100EVM.

I overlooked something in original post, you said you don't have a chemID match? Did you use the GPCchem tool? We need to either find a close enough match in our system or characterize your cells before SOC will be accurate.

I assume if you don't have a chemid match, you also have not completed a learning cycle. This will need to be completed as well, after a chemID match is obtained.

In terms of the inaccurate current reading, please recalibrate your gauge.

Perform voltage calibration with the BQ34Z100-G1 | Video | TI.com

Perform current calibration with the BQ34Z100-G1 | Video | TI.com

Regards,

Diego

0 Jason Tedford 11 months ago in reply to Diego

Prodigy 40 points

I have already preformed the Voltage and Current calibrations. Is there an instructional video on using the GPCChem tool? I have the SLVA725A Guide so I understand I need to create a config.txt and .csv file. However, the manual implies that this can be done with BqStudio and I can't find the utility GPC Packager. I suppose I could use the Start Log function and post process the data but I'd rather use the standard tool if I can find it.

+1 Diego 10 months ago in reply to Jason Tedford

TI__Mastermind 26605 points

Hi,

So, you just simply start a log file using BQstudio then follow the steps in the document.

There is a video at the bottom of this page: GPCCHEM Application software & framework | TI.com

Regards,

Diego

Power management

Power management forum

BQ34Z100-R2: BQ34Z100-R2