• State TI Thinks Resolved
  • Locked Locked
  • Replies 9 replies
  • Answers 4 answers
  • Subscribers 64 subscribers
  • Views 1654 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

WEBENCH® Tools/BQ34Z100EVM: regarding learning cycle test

manoj sai
Expert 2305 points
Part Number: BQ34Z100EVM
Other Parts Discussed in Thread: BQSTUDIO

Tool/software: WEBENCH® Design Tools

Hello everyone,

I am  testing battery of type  :  Lead acid , 12v ,1.3 Ah capacity.

Iam able to get voltage of 12v in bqstudio. To get  the remaining parameters , i started performing learning cycle.

i updated the chem id to 0802, design capacity :1300 Mah , design energy :15600

Enable IT
2. Send Reset command (0x0041)
3. Charge the pack to charge termination.
4. Rest until the OCVTAKEN flag sets
5. C/7 Discharge to the termination voltage
6. Rest until the OCVTAKEN flag sets. At this point, QMax should update and the Update Status should increment to 0x05
7. Charge the pack to charge termination
8. Rest until OCVTAKEN flag sets
9. C/7 Discharge to the termination voltage
10. Rest until the OCVTAKEN flag sets. At this point, the Ra table should update and Update Status should increment to 0x06

As per declared in previous posts,

i followed above posts , i had  charged the  battery and after few hours, ocvtaken flag has been set.

next step i discharged the battery by considering: C/7 parameter -->1.3Ah / 7=0.18 A ,-->R=12/0.18=66ohm,  i had taken 66ohm resistor  , started discharging the battery

after 5 hours rest no change in learned status and ocvttaken flag also not set.

I am  attaching the log . so kindly help me . my settings in bqstudio are 

I am  attaching the log of discharging the battery

discharge_log_7hours.log

  • 0
    TI__Mastermind 25955 points
    Hi Manoj,

    In reviewing the screenshots sent, there are a few immediate issues that require correction. For example, the number of series cells is set to 1. A standard 12 V battery pack is often 6s1p. Please correct the series value to 6. In addition, The values for your device are currently configured to that of a lithium ion battery, such as your terminate voltage, among others. Please modify these values to reflect your lead acid single cell voltages. For example, the Datasheet recommends a value of 100 for Cell Term V Delta, unlike the value of 200 in the screenshot. For lead acid chemistry, the datasheet recommends a default load mode of 0 and load select of 3 for the learning cycle.

    Prior to changing the series value, please make sure to first change the Flash Update OK Voltage to 1000 mV.

    Additionally, at 64000 mAh, this cell has a large capacity and will require additional configuration per the high capacity cell application note.

    In summary, please configure the gauge following the step by step instructions outlined in Section 8 of the Datasheet ( .www.ti.com/.../bq34z100-g1 ). Please amend these steps following the High Cell Count and High Capacity Applications Application Note ( www.ti.com/.../slua760 ).

    Sincerely,
    Bryan Kahler
  • 0 in reply to Bryan Kahler
    Expert 2305 points

    Hi Bryan Kahler, My battery capacity is 1.4 A h , how it could be High Cell Count and High Capacity Application , why considered 6400 Mah 

  • 0 in reply to manoj sai
    TI__Mastermind 25955 points
    Hi Manoj,

    My apologies. You're absolutely correct - I misread the the capacity as 64 Ah. Please follow the guidance above, but disregard the comment about the High Cell Count and High Capacity Applications Application Note.

    The key takeaway here is that your device needs to be configured with the 1s values of your battery. Please also ensure that Design Energy and Capacity are correct.

    Design Capacity = Cell Capacity x Number of Parallel Cells
    Design Energy = Design Capacity x Design Voltage (the 1s voltage for your cell, not the entire stack)

    Sincerely,
    Bryan Kahler
  • 0 in reply to Bryan Kahler
    Expert 2305 points

    Hi Bryan Kahler, Please give me the important values to be updated in bqstudio for learning cycle, i performed the learning cycle , i discharged the battery , rest for 5 hours and more , but no change in  learned status and max error. iam unable to crack the values to be update in bqstudio.

    In previous reply , i posted the values   chem id to 0802, design capacity :1300 Mah , design energy :15600 ,is it correct.?

    Have you checked4846.discharge_log_7hours.log the log which i had attached?

  • 0 in reply to manoj sai
    TI__Mastermind 25955 points
    Hi Manoj,

    There are many values you need to change. The default values are set up for a lithium ion gauge. Please change fields with voltage as unit that are for a lithium-ion cell (generally 3000 mV to 4200 mV). The Single cell Voltage values for your cell are much lower.

    Assuming your design capacity is 1300 mAh, with a lead acid cell your design energy should not be greater than 2860 mV. Please use the formula given above and follow the steps outlined in section 8 of the Datasheet. Once you have followed these steps, and repeated a learning cycle at

    These values are incorrect. Please use the formula above and those in the TRM to configure your gauge.

    This post may be of some help: e2e.ti.com/.../2355108

    Sincerely,
    Bryan Kahler
  • 0 in reply to Bryan Kahler
    Expert 2305 points
    hi Bryan Kahler,actually design energy =design capacity*voltage -->1300 mah*12 ---15600 mv ..is it wrong? how do you obtain 2860mv
  • 0 in reply to Bryan Kahler
    Expert 2305 points
    Hi Bryan Kahler, I dont have the datasheet of battery which iam using , how can i update the remaining parameters.
  • 0 in reply to manoj sai
    Expert 2305 points

    AT 12V1.3AH.pdfHi Bryan Kahler, I updated the datasheet of battery , please help me out the parameters which i have to update bqstudio

  • 0 in reply to manoj sai
    TI__Mastermind 25955 points
    Hi Manoj,

    These values are based on the single cell voltage, not the total stack voltage. a 12 V lead acid battery is actually 6 lead acid cells in series.

    With:

    design energy = design capacity * single cell voltage

    and

    design capacity = capacity * # of parallel cells

    With a 6S1P configuration, assuming a nominal single cell voltage of 2 V, we should see a design energy = 1300 mAh * 2 V * 1 cell in parallel = 2600 mAh

    Sincerely,
    Bryan Kahler