BQ34Z100-G1: BQ34Z100EVM: Step problem regarding SLUA334B, part 2

Kevin Braun47

Part Number: BQ34Z100-G1
Other Parts Discussed in Thread: BQ2002E, GPCCHEM, BQSTUDIO, , BQ34Z100, GPCRA0

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

over 6 years ago

0 Kevin Braun47 over 6 years ago

Intellectual 450 points

IT-5.zip

0 Onyx Ahiakwo over 6 years ago in reply to Kevin Braun47

TI__Guru* 76230 points

Hi Kevin,
There are several things wrong with your files and cycle.
-Are you using the correct chem id? Did you use gpcchem to identify your chem id?
--Design capacity is 1500mAh? Is this value correct for your cells? If yes, i suggest using a lower discharge rate of c/7.
-Also, i do not see your fc flag getting set. You ensure charge termination conditions are met so that the fc flag gets set.
- Also during your relaxtion after charge, your current isn't 0. There is still some current going into the battery. Why is that.

thanks
Onyx

0 Kevin Braun47 over 6 years ago in reply to Onyx Ahiakwo

Intellectual 450 points

Hi again Onyx,

My replies:
- In a previous e2e thread, I was having trouble with gpcchem. I sent you my files and you told me it was 6113
- Yes, 1500mAh in most cases. We may also offer 2000mAh in the future. I will try C/7 next go around.
- Yeah, that's what I'm running in to. FC won't set and MaxError won't change to 5%. Can you point me to what charge term conditions I screwed up on?
- Current going into the battery is the "trickle pulse charge" generated by the BQ2002E
- -> However, the next morning I disable the BQ2002E. Even after doing that and waiting for hours, FC never sets.

...kevin

0 Onyx Ahiakwo over 6 years ago in reply to Kevin Braun47

TI__Guru* 76230 points

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

0 Kevin Braun47 over 6 years ago in reply to Onyx Ahiakwo

Intellectual 450 points

Hey Onyx,

I still cannot get FC to set. Here's an updated .gg file

...kevin

IT-7.zip

0 Onyx Ahiakwo over 6 years ago in reply to Kevin Braun47

TI__Guru* 76230 points

Hi Kevin

Do you have the new logs? After you made your updates, did you issue a reset to the gauge?

thanks
Onyx

0 Kevin Braun47 over 6 years ago in reply to Onyx Ahiakwo

Intellectual 450 points

I did not send a reset message after updating the values (stat/control reg is still 0x0016, full-access). Is it too late now that I've turned on IT ENABLE?

...kevin

0 Onyx Ahiakwo over 6 years ago in reply to Kevin Braun47

TI__Guru* 76230 points

No. Issue the reset and repeat your test.
thanks
Onyx

0 Kevin Braun47 over 6 years ago in reply to Onyx Ahiakwo

Intellectual 450 points

Still no luck Onyx. Here are my latest log, register and GG files

...kevin

IT-7a.zip

0 Kevin Braun47 over 6 years ago in reply to Kevin Braun47

Intellectual 450 points

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

0 Onyx Ahiakwo over 6 years ago in reply to Kevin Braun47

TI__Guru* 76230 points

Hi Kevin,
This gauge does not have fets so there are no fet commands.
thanks
Onyx

0 Kevin Braun47 over 6 years ago in reply to Onyx Ahiakwo

Intellectual 450 points

That's good to know. Any other things I could try?

Regards,

...kevin

0 Yevgen Barsukov over 6 years ago in reply to Kevin Braun47

TI__Intellectual 1080 points

If learning in device still fails, you can use on-line gauge parameter calculator, using the same log file and fresh (not learned) GG file exported right after chem ID was programmed. Gauge parameter calculator can be found here:
http://www.ti.com/tool/GPCRA0

0 Kevin Braun47 over 6 years ago in reply to Yevgen Barsukov

Intellectual 450 points

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

s700-report.zip

s700.zip

0 Yevgen Barsukov over 6 years ago in reply to Kevin Braun47

TI__Intellectual 1080 points

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.

0 Kevin Braun47 over 6 years ago in reply to Yevgen Barsukov

Intellectual 450 points

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

0 Yevgen Barsukov over 6 years ago in reply to Kevin Braun47

TI__Intellectual 1080 points

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

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BQ34Z100-G1: BQ34Z100EVM: Step problem regarding SLUA334B, part 2