Hi Team,
I have the following queries with the charging IC BQ24616 .Although i have read the datasheet ,I have the below queries to be clarified to proceed with the design.
Attached the design schematics FYR.
Note:The VBAT voltage is designed for 12.6V and not 8.4V
1.The Voltage on the VFB pin is 2.05V .I have verified the TS pin and it is set to 70% and is between 0 to 45degC .The voltage on the TS pin is >2.4V.So the VFB should be 2.1V as per spec but the voltage is 2.05V on VFB and hence the Vbat charging voltage is switching between 12.6V and 12.3 but the designed voltage is 12.6V charging. Please let us know why it is switching and not constant 12.6V?
2.We have designed the ISET2 to 0.6A.So the termination current would be 0.6A and the battery stops/terminates charging when the current goes below 0.6A.Please confirm on this understanding ?
3.Kindly let us know how the battery recharge cycle works? As per the datasheet ,recharge starts when the battery voltage has dropped below the recharge threshold (VRECHG).where do i measure the VRECHG voltage i.e at which pin the voltage should fall below 50mV(mentioned w.r.t VREG in spec).I could not understand the recharge threshold from the datasheet. As per my requirement, the charging voltage is 12.6V.At what battery voltage threshold below 12.6V ,the recharge cycle starts? Kindly let me know the definite threshold value dropping from the 12.6V.
4.We have tried charging the battery in constant current mode(1A ISET1 pin updated) but the battery is switching between 1A and 0.6*A) Why is it not charging constantly at 1A and switching between the mentioned current values.Is it the expected behavior?
5.Is there any way to read the voltage of the battery during charging time. We could read the charging voltage of the battery but require to read the battery voltage during charging. Kindly suggest any way to read the battery voltage while charging.
6.Also kindly elaborate the working on how the IC is reading the battery voltage. I ve checked the section 8.3.5 in datasheet but it was not mentioned .
Please clarify on the above queries which would be very helpful in better understanding of the design.