Hi,
I have a bq34z100 with a LiIon battery pack and I am trying to complete the Optimization calibration specified in SLUA334B. On step 8, update status is suppose to change to 0x06, however it stays at 0x05. The Qmax and update status values changed correctly on step 7. The details of the steps, and battery are below and the *.gg file is attached.
Please let me know what to do to get a successful calibration.
If additional information is needed please let me know, this is the first battery & gas guage I have worked with.
Details:
Steps:
When no close Qmax value is known:
1. Even though accurate capacity is unknown, set Qmax and design capacity to the cell capacity shown
in the data sheet. Do not send IT enable command 0021.
2. Send SMB command 46, word 0006 to turn on the FETs.
3. Discharge the pack down to termination voltage at a C/5 rate.
4. Let it relax for 5 hours or more.
5. Send the IT enable command (0021). Bits QEN and VOK in Operation Status are set.
6. Charge pack to full capacity until the taper current is reached and the FC bit is set.
7. Let it relax for 2 hours. Qmax is learned at this point; this can be verified by MaxError changing to 3%
and Update Status to 5%.
8. Discharge the pack down to terminate voltage at the typical low rate of your application. For laptops, it
is usually C/5. The MaxError changes to 1%, and the Update Status changes to 6%.
9. Repeat steps 4 and 6 to 8 one more time to verify the gas-gauging accuracy.
Battery:
- 4S1P Pack. (4 18650 LiIon cells in series)
- 14.8 volt nominal pack voltage (3.7V per cell)
- 12.0 volt end of discharge voltage (3.0V per cell)
- Max charge ratings of 2.6A and 16.8 V (4.2V per cell), though our application will charge at 1.5A or less.
- Pack capacity 2800 mAHr (41.44 WHr total pack capacity)
- 4.5 A expected maximum discharge current.
File:
calibrated.gg
The gg file after step 8.
4.5 A expected maximum discharge current.
(Please visit the site to view this file)