• Resolved

BQ34Z100-G1: Incorrect SOC reported

Prodigy 30 points

Replies: 3

Views: 82

Part Number: BQ34Z100-G1


I have done following to setup the fuel gauge.

1. Updated design capacity to 2600

2. Updated CC threshold to 90% of design capacity

3. Updated Q max to 2600

4. Updated design energy to 19240

5. Updated cell charge voltage range to 4200 for all temperature ranges

6. Updated number of series cells to 2

7. Updated pack configuration to 0x08a1

8. Updated charge termination

Taper current 150

Min taper capacity 5

Cell taper voltage 100

Taper window 40

TCA set 99

TCA clear 95

FC set -1

FC clear 98

9. Updated pack learning config

Load select 1

Max res factor 15

Min res factor 3

Min passed charge first qmax 90

Max qmax change 30

Cell term v delta 200

Max res cale 5000

Min res scale 200

10. Calibrated voltage divider

11. Calibrated sense resistor

12. CC offset

13. Board offset

14. IT Enable

15. Learning cycle

Everything seems to work well and the Max Error shows 1% at the end.

Issue appears in form of wrong SOC (lower sometimes 65% sometimes 90%) value after a few hours of pack sitting idle. The pack voltage show 8340 which is very close to fully charged.

Any ideas of what is going wrong?


  • hi Kamran,

    What chem id are you using? Is this an LFP cell with a flat voltage profile? I am suspectiing a rem cap simulation was run and as a result SOC adjusted because of the flatness of the OCV curve. Do you have a log and a gg  file showing this?



  • Hi, Kamran

        Have you verify the chemical ID of the cells you are using, I have not seen a step to download chem ID data to target device.

        What is the update status after the learning cycle?

        Have you sent IT Enable command or reset command when the battery voltage had not been fully settled?

        How is the temperature accuracy and stability?

        Can you attach a log file showing the SOC fluctuating up and down during relaxing and a gg file of target device?

  • In reply to Steven Yao:

    Sorry for the delay, I was programming the gauge using the MCU on PCB but since then I have purchased EV2400.

    It looks like I have incorrect chemistry ID selected.

    Update status is showing 6

    Could you please elaborate on when IT enable should be sent?

    Temperature is accurate and stable but it did fall to about 10 degree c and after which SOC was incorrect.

    I will reconfigure using bqstudio and report back.