Part Number: BQ34Z100
Hi!
We wanted to replace in our multi cell and multi chemistry battery gauge design the old BQ2040 chip with the new BQ34Z100 offered by TI. So, to be familiar with the new one, we used a TI development kit, picked up a brand new 12V 7Ah battery which commonly used in UPS, downloaded a very similar chemistry profile (0800 chemistry ID, Leoch 7200mAh valve regulated Lead-Acid) and started charge/discharge cycles monitored with the TI Battery Studio.
After 3 complete cycle, there are strange data (for me... :), and I can not get correct answer about the battery fully charged and remained capacity. The "DOD0 Passed Q" and the "Qmax Passed Q" data counting up and down in one discharge/charge cycle, but never overwrite the "Remaining Capacity" or "Full Charge Capacity" fields. The Full Charge Capacity is always 965mAh (State Of Health = 14% ?????), despite both Qmax Passed Q and the DOD0 Passed Q is over 7000mAh on full charge (charge current drops below 0.1A from the initial 2A CC/CV charging method) or full discharge (cell voltage drops below 1800mV).
On charge, the Remaining Capacity counts up until 965mAh, and stops while the Qmax carry on counting. If I cut the charge current at fully charged state, and leave the battery without load, the Remaining Capacity immediately falls to zero.
The "True RC" and "True FCC" values follow the DOD0 Passed Q and Qmax Passed Q values while the charge or discharge is active, but when the cycle is finished (charge current or load current is zero) they change to the mysterious 965mAh..
In the old battery gauge chip (BQ2040) simply I had to read the FCC and RC registers, and I got acceptable values. So, can anybody tell me the algorithm how I can detect the actual FCC and RC of the battery in the BQ34Z100, because based on the test I don't find exact method for it.
Thank you.
Sincerely, Sandor
So, where can I find the actual