Hi,
I am running some tests on a laptop battery pack which has bq20z955 chip inside. Sometimes the SMBus communication with the pack ceases to work after the test has been running for some time: the pack can still be charged and discharged, but communication is not working and logging data is halted. The log also indicates that for past one minute or so before communication failure the battery pack is constantly sending the same values out, indicating some sort of a freeze. The pack seems to reset itself after being left completely disconnected for some time.
What could cause the communication failure or the chip jam like this? The maximum current I am using to charge and discharge is not all that high (0.5C rate translating to 2.2A) but the discharge current is very random, constantly changing with sudden sharp jumps. The battery pack does not heat up very much either. The logs indicate internal temperature of 30 degrees at the highest, and the temperature is not even at that level when communication fails. Could the reason be the changing discharge current?
Thanks.