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Part Number: BQ20Z80

We use the TI BQ20Z80DBT Gas Gauge IC in one of our smart lithium ion rechargeable battery products designed for medical use. The most common occurring manufacturing test failure for this medical battery is NO COMMUNICATION at one of our electrical test stations. Communication issues have not been reported at the customer level for this medical smart battery. I am recommending a single manufacturing retest be allowed for all first time, no communication production test failures, to our quality team, which will require a modification to our present official test procedure. From my perspective as an experienced electronic technician, it is acceptable to perform a single retest after a first time no communication test failure. Two potential causes for no communication here include tester error/malfunction (our fault) and TI BQ20Z80 Gas Gauge IC hardware malfunction. If the BQ20Z80 successfully communicates on a second test attempt, my confidence in the reliability of our medical smart battery has not been reduced. If our medical smart battery fails for no communication again, upon a second attempt and retest for BQ20Z80 communication, my confidence in reliability would decrease. We are allowed to replace the PCBA once for any test failure. Due to strict regulations being a medical battery, we are very limited with the rework or retest we are allowed to perform at production level. If after a single PCBA replacement, the battery assembly passes all of our testing, it is allowed for shipment to our medical customer. My question is, what is the reliability of a Texas Instruments BQ20Z80DBT Gas Gauge IC upon failing initially for no communication and passing for communication testing upon a second attempt?

  • Hello Dan,

    It is normal practice to retry communication in case of failure. This applies to systems that communicate with batteries as well, not just manufacturing.

  • Hello Shirish, thank you for your response, which will be helpful for us to get approval from our medical customer to allow a retest for no communication production test failures. My idea is to allow one retest for all first time no communication production test failures. What is your professional opinion/perspective on allowing a 2nd retest for the bq20z80 gas gauge?  What do TI engineers think, regarding reliability after allowing a 2nd or 3rd retest for no communication? 

  • Hello Dan,

    BQ20Z80 is reliable as long as it is operating within recommended parameters. We cannot make a recommendation for your test because there are many parameters that must be controlled during production to ensure reliability of the board. An example is ESD which can cause failures much later.