Part Number:BQ27411-G1
I am having several issues with this part in an application monitoring a 18650 3000mAHr battery where I am just trying to learn the battery in my hardware configuration.
1) I noticed that when reading the Data Memory State subclass the check sum seem to be on the first 30 bytes out of 32 bytes, the checksum seems to appear in byte 31 and this is reflected when I read the BlockDataChecksum register (0X60), the two values are equal. The document SLUUAS7B Rev 2015 states the checksum is over the 32 byte memory area. If I calculate the checksum over the 32 bytes of data it will be rejected. I have not tried any other subclasses yet to see if it is consistent throughout.
2) I am getting WD timeouts (High Byte bit 6 of the Control_Status 0X0000 register. These occur if I have set the Design Capacity to 3000 (as determined by my battery) and the battery is charging. They do not occur if the battery is discharging or if the Design Energy is not set by my software. I am successfully able to set the Design capacity and can verify that by reading register 0X3C to see that it reflects my value of 3000.
3) If I update the Design Capacity to 3000, The design Energy to 11100 (3.7*3000), the taper rate to 1500, and the terminate voltage to 3200 and start discharging the battery and monitor the registers Nominal Available Capacity, Full Available Capacity, Remaining Capacity, FullCharge Capacity, and State of Charge I get values that don't make a lot of sense even after allowing for a long period (overnight) of discharge time. I can't seem to charge the battery without the device flagging a watchdog reset and not requiring a reset to get running again.
Currently there is no sense in even trying to create a golden file for my batteries as the device is just not functioning properly.
Any advice on this would be helpful before I remove this part from the design and re-layout the board for a different solution.
Thanks