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I still cannot get passed the initial Step 6 in "When no close Qmax value is known:". I have taken suggestion on similar threads and I believe that I have "most" Data Flash values correct, but I still must be missing something.
My systems is a 2 cell NiMH AA battery system with a BQ2002E as the charge controller. I've attached the latest gg file, current pic of the main Registers' states and a log file
...kevincycle1_5.log
Hi Kevin,
Because you are using NiMH chemistry, your charge termination has to be based on -DV or DT/dt conditions and not based on taper current conditions. I recommended changing your NiMH Cell Negative Delta Volt to 4mV from 17 and reduce the NiMH Cell Negative Delta Time from 16 to 5s. Change NiMH Delta Temp Time to 90s, and NiMH Hold Off Time to 40s. Hopefully, this will allow FC flag to get set.
For the relaxation period, you can't be trickle pulse charging. The charger has to be cut off to allow an OCV measurement to get taken.
thanks
Onyx
Onyx,
In SLUA334B, step 2 says to send SMB command 46, word 0000 to turn on FETs. I don't see this command anywhere in the BQ34Z100-G1 datasheet or in BQStudio, so I ignored it. Could this be the reason I cannot get FC to set and ME < 100%?
...kevin
Hi Yevgen,
I submitted the report for GPCRA0 (attached) and the failed results (also attached in next upload). Where do I make corrections to the Data Flash Memory for this? I could not find a reference to "OCV 1379mV" in the BQ34Z100 datasheet or BQStudio/EV2300
...kevin
The issue is not with data-flash memory but with the cell voltage being too high compared to your chosen chem ID OCV in the database.
This can happen either (1) if the chem ID was chosen incorrectly, or (2) if there is some problem with the test that caused voltage to be too high. (2) seems to be the case here, because there is insufficient relaxation time after charge so voltage could not stabilize at lower value yet, resulting in voltage during subsequent discharge being too high, higher than OCV.
Usually 2 hrs is minimal recommended rest time after charge before discharge starts. But in case of some higher impedance cells even longer rests times need to be used. You can see that rest time is sufficient when voltage stops changing. I would try 5 hr rest after charge in your case to make sure.
Thank you Yevgen,
Today I am doing a careful redo of the GPCRA0 test. In the meantime, how do I know that I have the correct chem ID selected? I was told to use chem ID 6113 by Onyx.
My system is a 2 * AA size NiMH at 1500mAh (yes, small). May want to go up to 2000mAh in the future.
...kevin
Best way to verify chem ID is to run charge / relax / discharge /relax test.
Here:
1) charge is done to full cell manufacturer specified conditions,
2) rest is 2 hrs (can be 5 hrs if voltage is not fully stabilized),
3) discharge (at C/10 rate for Li-ion and C/20 rate for NiMH or lead-acid battery),
4) after discharge rest of 5 hrs.
Resulting log file is submitted to chemistry selection tool.
See details on the format of the submission in the instruction manual here:
Regards,
Yevgen