BQ27421-G1: Learning Cycle necessary?

Co Ve

Part Number: BQ27421-G1
Other Parts Discussed in Thread: EV2400, BQ40Z50

Hello,

We are developing a product with a BQ27421-G1 fuel gauge. I have used Battery Studio along with the EV2400 USB to i2c inteface to set the correct parameters for the fuel gauge, and I then clicked on "Save to Gauge" to write these parameters onto the gauge.

1. Will this be written in the gauge non-volatile memory?

2. Is this actually enough for the gauge to provide me with accurate data? Or do I also need to execute a "Learning cycle"?

3. If the above is yes, will I be able to extract the data fro the learning cycle and flash it into the memory when I get to mass production?

Thanks

over 2 years ago

0 Jessica H. over 2 years ago

TI__Genius 11535 points

Hi Co Ve,

1. Yes, this is written to non-volatile memory

2. It is enough for the gauge to provide accurate data without a learning cycle as long as you have changed these parameters to fit your application: Design Capacity, Design Energy, Terminate Voltage, and Taper Rate

3. In the event you run a learning cycle, you will be able to extract the data to a Golden Image file and use that when you get to mass production

Best,

Jessica

0 Co Ve over 2 years ago in reply to Jessica H.

Prodigy 170 points

Hello,

Could you clarify how I could flash the memory of the fuel gauge during the mass production?
Would I be able to use my MCU to set some i2c register values? Or something else?

Thank you

0 Co Ve over 2 years ago in reply to Co Ve

Prodigy 170 points

Hello,

I have seen in the documentation that it is possible to flash the golden image to the fuel gauge using the EV2400 USB to i2c inteface. But is there another way? This is really not convenient for the assembly line that we currently have. Can we convert the golden image into a series of registers write that can be done from a MCU?

Thanks

0 Jessica H. over 2 years ago in reply to Co Ve

TI__Genius 11535 points

Hi Co Ve,

Sorry for the delayed response. I suggest you take a look at the "Going to Production" document if you have not already done so. Although they are for different gauges, the "BQ34z100 Going to Production" and this BQ40Z50 Training (skip to the end where they talk about production) could also be useful. You don't necessarily need the EV2400 but you will need a way to communicate via i2c.

Best,

Jessica

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BQ27421-G1: Learning Cycle necessary?