BQ34Z100-G1: Voltage calibration "Cell Voltage correction is beyond allowed range"

Remko

Prodigy 70 points

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

Hi,

I'm trying to use a 12V 2.3Ah Lead-acid battery with the BQ34z100EVM and EV2400.

Following the Step-by-Step Design Procedure in the BQ34Z100-G1 datasheet on page 50.

Step 1:

Design Capacity: 2300mAh
Design Energy: 2300mAh * 12V = 27600 mWh
Cell Charge Voltage Tx-Ty: 2300mV

Step 2:

LED_Comm Configuration: default
Alert Configuration: default
Number of Series Cells: 6
Pack Configuration: VOLSEL bit set

On the BQ34z100EVM the following jumpers are set:

J5: >5V
J2: 16V
J3: A
J6: EXT
I2C: connected

Step 3:

Voltage Divider: (300000+16500)/16500 = 19182
Flash Update OK Cell Volt: 2800mV * 6 * 5000 / 16000 = 5250 mV ("Value is beyond maximum value defined for parameter")

Then it says "Use the Evaluation Software to calibrate to the applied nominal voltage; for example, 24000 mV."

In bqStudio v1.3.90 I go to Calibration

Tick the Calibrate Voltage box

Fill in 12890mV (measured at BAT+ and BAT- screw terminals)

Calibrate Gas Gauge

"Calibration - Cell Voltage correction is beyond allowed range."

What am I doing wrong? The gauge reports a voltage of 2208 mV

Thanks,

Remko

over 4 years ago

0 Bryan Kahler over 4 years ago

TI__Mastermind 25955 points

Hi Remko,

I have reported this issue to the tools teams. In the interim as a workaround, please manually modify the value of voltage divider using the values given in this video: training.ti.com/bq34z100-g1-voltage-calibration

The value of voltage divider may be modified until the voltage reported is actual. It will need to be slightly higher than the value given in the video.

Sincerely,
Bryan Kahler

0 Remko over 4 years ago in reply to Bryan Kahler

Prodigy 70 points

Hey Bryan,

Thanks for your reply.

Even with the voltage divider at the maximum value, I get 7537mV instead of the 12.89V I measure with my multimeter.

Could this be a hardware problem?

At Vscale Lo and Vscale Hi I measure 0V, but when I apply a lower or higher voltage at the BAT+ and BAT- terminals I do see the difference in BqStudio.

Edit:

I just measured Vscale Hi and Low with a oscilloscope. When I click reset in BqStudio-> Vscale Hi = 12V and Vscale Lo = 0.6V.

0 Bryan Kahler over 4 years ago in reply to Remko

TI__Mastermind 25955 points

Hi Remko.

Please ensure series = 1 and VOLTSEL = 1. Then set the voltage divider value where Voltage Divider: (300000+16500)/16500 = 19182

You should now see a value close to the applied voltage.

Sincerely,
Bryan Kahler

0 Remko over 4 years ago in reply to Bryan Kahler

Prodigy 70 points

Hi Bryan,

I have set Number of series cell = 1 and in Pack Configuration VOLSEL = 1.
Voltage divider = 19182.

The voltage in BqStudio is now 2202mV. The voltage I measure with my multimeter is 12860mV.
So this is still quite far off.

Best regards,
Remko

0 Bryan Kahler over 4 years ago in reply to Remko

TI__Mastermind 25955 points

Hi Remko,

With these settings do you still see the error in the calibration window? IF so, please send a screenshot of the error.

Sincerely,
Bryan Kahler

0 Remko over 4 years ago in reply to Bryan Kahler

Prodigy 70 points

Hi Bryan,

I still get the same error:

0 Remko over 4 years ago in reply to Remko

Prodigy 70 points

I just figured out my issue, apparently the VOLSEL bit was not set.
I thought green meant set and red meant cleared, but it's the other way around.

After setting the VOLSEL bit, the right voltage is finally shown.

Thanks for all your help!
Remko

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BQ34Z100-G1: Voltage calibration "Cell Voltage correction is beyond allowed range"