BQ35100: ACCUMULATOR MODE

Alexis COGREL

Part Number: BQ35100

Hi TI team,

Now, I am studying to use BQ35100 in ACC mode. I would like to have more explanation about this mode and confirm my understanding of datasheet.

In our application, most of the time our system is in low power and our profile current presents a very quick active current around a few 1-100ms and not exceed 100mA.

Datasheet say: "In this mode, the bq35100 device measures and updates cell voltage, cell temperature, and load current every 1 s and begins accumulating after GAUGE_START is received.[...]"

That why I am seeking that ACC mode could not be able measureour profile current because sampling of this mode is every 1s. Could ACC mode be able to monitor capacity with type of current profile (when current go to high during a few ms)?

Regards,

Alexis.

over 6 years ago

0 Onyx Ahiakwo over 6 years ago

TI__Guru* 76230 points

Hi Alexis,

The ADC used for current measurement is a delta sigma integrating converter so it is not just instantaneous current it is measuring. I believe it should be able to handle your load profile well

thanks

Onyx

0 Alexis COGREL over 6 years ago in reply to Onyx Ahiakwo

Prodigy 150 points

Hi Onyx,

What is the sampling frequency of ADC to measure capacity accumulated?
To my mind if it is 1s, it should not enought to probe our profile current.

Regards,

Alexis.

0 Onyx Ahiakwo over 6 years ago in reply to Alexis COGREL

TI__Guru* 76230 points

sampling frequency is 65kHz, conversion time is 1s.
thanks
Onyx

0 Alexis COGREL over 6 years ago in reply to Onyx Ahiakwo

Prodigy 150 points

OK, that why current measurementis done every 1s.
And so about accumulated capacity is the same measurement every 1s? How BQ35100 calculate capacity for a pulse of current?
For example, a pulse of 20mA during 200uS.

Regards,

Alexis

0 Onyx Ahiakwo over 6 years ago in reply to Alexis COGREL

TI__Guru* 76230 points

That is almost negligible compared to the capacity of the battery. But with a sampling frequency of 65Khz, it will still capture that into the accumulated capacity.

Its best for you to evaluate the gauge with your load for you to be convinced

thanks
Onyx

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BQ35100: ACCUMULATOR MODE