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BQ34Z100-G1: Achieving a Successful Optimization Cycle - FC Flag Set Fail

Rodrigo Jordao
Prodigy 10 points
Part Number: BQ34Z100-G1
Other Parts Discussed in Thread: BQ34Z100EVM, EV2400, GPCCHEM

 Hello,

I need help understanding the configuration parameters for the BQ34Z100-G1.

I've been trying to complete a learning cycle for over a week now. I've also seen a few threads about similar issues and I've tried a few configurations. I can't complete or get past the [FC] bit that should be set automatically or the update status that should be set to 0x05. I've included a log report and .srec files.

Problem:

. [FC] bit does not set automatically after a complete charge;

. I get OCVTAKEN for the fourth step in SLUA925 but the Update Status() register does not get updated to 0x05.

Equipment:

. BQ34Z100EVM - Evaluation Board

. EV2400 - Interface Board

. Battery 18.175V (nom) 3500mAh | 5S/S

. Battery Charger (1.5A)

Design Details:

. Battery chemistry is 2059 for INR18650 MJ1 cell.

. Battery depletes at <15V. This battery pack has a over-discharge protection that cuts off battery supply. Therefore, term voltage is set to 3100mV (15500mV);

. I've played a bit with taper current and cell taper voltage values. Need more clarification and advice of proper values to be set in here.

. Decreased the cell charge voltage to 4100mV (20500mV). This was an attempt to trigger FC flag earlier.

. Pack configuration register is only set to NI_DV, I'm not sure if NI_DT needs to be set as well.

. No idea how to set the voltage divider and Flash Update OK Cell Voltage values. Values are set according to values suggested in another post. The procedure to select the voltage divider doesn't make sense. If I do the calculation, the values are outside the range permitted in the registers.

Any help is appreciated. Thank you.

Batteryinfo.zip

  • 0
    TI__Mastermind 37761 points

    Hey Rodrigo,

    Section 3.7 of the TRM talks about valid charge termination. Just based on an initial look it seems that your test conditions are passing the requirements for the taper current method of valid charge termination. I will need more time to go more in depth of my review. I will get back to you the beginning of next week.

    Regards,

    Nick Richards

  • 0 in reply to Adrian
    Prodigy 10 points

    Hey Nick,

    Thank you for your promptly reply.

    Yes, you were right. I ran another test yesterday with modified charge termination specs and I was able to set the FC. Thank you!

    I think the problem was the Chg Current Threshold value was too low and outside the taper window. I found SLUA664 document to be very helpful.

    Now, the Update Status() register is still not updating to 0x05. I did a bit of reading yesterday and I think is my C rate discharge. I'm running a C/10 today, much slower compared to what I was doing before (I was discharging the bat in 3h). My assumption is that the Qmax is not setting because of the 90% requirement on the DOD?

    I'm also logging this cycle so I'll post the result soon.

    Thanks again.

  • 0 in reply to Rodrigo Jordao
    TI__Mastermind 37761 points

    Hey Rodrigo,

    That's good to hear. Today is a holiday and no one is in the office. We will get back to you next week.

    Regards,
    Nick Richards

  • 0 in reply to Adrian
    TI__Mastermind 37761 points

    Hey Rodrigo,

    Send the new log when you finish. Just want to confirm how you obtain the ChemID for the battery, was the ChemID already in our chemistry database? Or did you use the GPCCHEM tool?

    Regards,

    Nick Richards