BQ34Z100-G1: Cycle count unchanged

Jack Wang

Part Number: BQ34Z100-G1
Other Parts Discussed in Thread: BQ34Z100

Tool/software:

Hello:

In the charge and discharge cycle test, it was found that the number of cycles of BQ34Z100-G1 remained unchanged. What causes the number of cycles not to increase? Attached are the LOG and GG files recorded by Battery Management Studio. Please help analyze this problem.

3821.Bq-Log.zip

11 months ago

0 Diego 11 months ago

TI__Mastermind 26175 points

Hi,

Please try to log multiple charge/discharge cycles in a row and see if cycle count increments. Please charge the pack to full and discharge to empty.

Regards,

Diego

0 Jack Wang 10 months ago in reply to Diego

Prodigy 80 points

Hi，

At present, it was found that the number of cycles of two batteries did not increase during normal use. The previous first battery had returned to normal after I sent the reset command and the cycle count could be increased. Attached is the test log of the second battery whose cycle count did not increase. Please analyze what happened, thank you!

BQ-Log-1.zip

0 Diego 10 months ago in reply to Jack Wang

TI__Mastermind 26175 points

Hi,

After the reset Cmd was sent, cycle count began to increment as expected?

When I look at the log file the FC bit never sets, the FC bit needs to set when the battery is fully charged.

Regards,

Diego

0 Jack Wang 10 months ago in reply to Diego

Prodigy 80 points

Hi,

Thank you for your reply！

Yes, after I sent the reset command to the first battery, I found that the cycle count could be increased when I tested it again.
The fact that the FC bit is not set is another issue that I find puzzling. I see that the Log data meets the full condition, but the BQ34Z100 does not set the FC bit.

Attached is today's charge-discharge cycle test log. After the battery was fully charged, FC was set, but the cycle count still did not increase after discharge to SOC 0%.
In fact, the user does not necessarily charge the battery to the full state every time during use. The CC Threshold I currently set is 2250mAH. The discharge capacity of Log data has exceeded this threshold. Why does the number of cycle count not increase? In addition to the CC Threshold, are there other conditions required for cycle count?

BQ-Log-2.zip

0 Diego 10 months ago in reply to Jack Wang

TI__Mastermind 26175 points

Hi,

Thanks for the log and all the information.

This behavior is strange, I will look into this some more.

In the meantime, can you reduce the CC threshold to something very small, maybe 500mAH. Let's see if this causes any cycle count updates.

Regards,

Diego

0 Jack Wang 10 months ago in reply to Diego

Prodigy 80 points

Hi,

Today, I tried to change the CC Threshold to 500 for many times, but found that this parameter could not be changed.After entering 500 in the input box and pressing the Enter button, the data remains the original value of 2250.So I tried to change other parameters, but found that it could not be changed either. I have checked the SS bit and FAS bit, both of which are 0, so the Access Mode of BQ34Z100-G1 is FULL ACCESS Mode, I don't know why. Below is a screenshot.