BQ40Z50-R1: bq40z50-r1 Term Voltage change from 6000mV to -2560mV

Star Xu

Part Number: BQ40Z50-R1
Other Parts Discussed in Thread: BQSTUDIO

My customer feedback that bq40z50-r1 Term Voltage change from 6000mV to -2560mV after 3 cycles learning(the packs are sealed)

The failure rate is 38%. They also do some experiments to change the term voltage data during seal mode.

In seal mode, Advance Comm SMB of BQstudio is used to read and write DF register. They found that it is completely feasible to read and write. Moreover, it can be normally modified when they write negative Numbers into the Term Voltage.

BQ40Z50-R1EVM is unavailable in my side. Please help verify this.

Thanks

Star

over 6 years ago

0 Batt over 6 years ago

TI__Mastermind 42535 points

Hi Star,

Allow me 2 days to check this. They have multiple posts saying the same thing. They need to prove that they are sealed when they write the values.

0 user4744921 over 6 years ago in reply to Batt

Prodigy 90 points

Any conclusions? I need to know

0 user4744921 over 6 years ago in reply to user4744921

Prodigy 90 points

The change in this value occurred when 3 was shelved after 3 was filled. So I change it from -- 2560 to 6000 and then I put it on hold for a few days and then it automatically changes back to -- 2560. We are waiting for your analysis results. Could you please help us solve this problem as soon as possible?

0 Batt over 6 years ago in reply to user4744921

TI__Mastermind 42535 points

I confirm that term voltage can be changed by sending command 0x5d even in sealed mode. The command 0x5d is defined in the TRM as

Please do not use that command to set the value. It will work even when sealed.

Changing term voltage will change the gauging accuracy as that defines the point where the battery pack is supposed to be completely discharged.

0 user4744921 over 6 years ago in reply to Batt

Prodigy 90 points

Thanks！We know what you're saying, but we're just doing the read, not the write。

0 Batt over 6 years ago in reply to user4744921

TI__Mastermind 42535 points

Hi,

Please understand that the gauge by itself will not write term V. It has to be done by some host. Your host is probably talking to the gauge and requesting the turbo edv. Unless you use this function, there is no need to read or write it.

You have repeated the same questions more than 5 times here. My answers are the same as above. We suspect that it changed because your host wrote to it. If it changes to a negative value, then your gauging accuracy will be affected.

0 user4744921 over 6 years ago in reply to Batt

Prodigy 90 points

Thank you very much! We're checking ourselves.

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BQ40Z50-R1: bq40z50-r1 Term Voltage change from 6000mV to -2560mV