BQ40Z50-R2: FC release setting

Hi Jonathan,

The FC bit can be cleared by the conditions below based on how the FC is configured in the SOC Flag Config B register. The bolded items below should be configurable in the .gg file.

Regards,

Anthony Baldino

Hi Anthony,

I understood the conditions

my question is more on how the algorithm works to disable charge till the RSOC drops <85%

I'm guessing this conditions sets the FC release and turns OFF charging when:

and then this will clear the condition and enable charge when?

• if i connect a power adapter to the port of the pack and it charges from 0%~100% uninterrupted ,if the RSOC falls to 91% and i remove the power adapter for a few seconds and i connect it again will the Pack charge or will it wait till <85% to release the Charge FET as per the spec to enable charge?
• i say this because although it says "Charge FET release <85%" this condition is only TRUE as long as power connection is not removed ,once it's removed for a few seconds and plugged again it will ignore that condition, is this expected 

Regards

Jonathan Kabangu

Hi Jonathan,

Jonathan Tshimama-Kabangu said:

then this will clear the condition and enable charge when?

The [FC] bit is only there to dictate when the cell has been fully charged, however it has no control over the [XCHG] bit, which will inhibit charge. The [TCA] bit declares when charge should be terminated, which does have control over this bit. You can see below that [TCA] has control but [FC] does not:

Jonathan Tshimama-Kabangu said:

if i connect a power adapter to the port of the pack and it charges from 0%~100% uninterrupted ,if the RSOC falls to 91% and i remove the power adapter for a few seconds and i connect it again will the Pack charge or will it wait till <85% to release the Charge FET as per the spec to enable charge?

Since the device is still powered, I believe that the gauge will still not begin charging due to the TCA bit still being set (if configured for 85%).

Jonathan Tshimama-Kabangu said:

i say this because although it says "Charge FET release <85%" this condition is only TRUE as long as power connection is not removed ,once it's removed for a few seconds and plugged again it will ignore that condition, is this expected 

So in application you are looking for it to be able to charge from 91% if the connection is removed?

Regards,

Anthony Baldino

Hi Anthony,

"So in application you are looking for it to be able to charge from 91% if the connection is removed?"

not quiet it's more of a question:

• does the TCA bit(Which turns OFF Charging ) only apply as long as the power adapter is not removed or is the condition interrupted if power adapter is removed?

Regards

Jonathan Kabangu

Hi Jonathan,

If the power adapter is removed and all power is removed from the device, I believe that the state that the TCA bit will be based on what value the RSOC or voltage is when the gauge is powered back on. If it is above the set threshold, the gauge should set this bit again. However, if it was set before but between the set threshold and clear threshold, it should not be set again since the device has to go through a full reset when powered back on.

Regards,

Anthony Baldino