Battery Issues - P0BBD code, voltage variation exceeded

Might I suggest that you can read out the details of your HV battery (including battery capacity and individual cell voltages).
There are 3 approaches to do this:

Approach #1:
https://www.insideevsforum.com/community/index.php?threads/read-battery-capacity-yourself-autel-ap200-breakthrough.9913/

Approach #2:
https://www.insideevsforum.com/community/index.php?threads/budget-battery-capacity-readout.10531/

Both of these threads are quite cluttered - I recommend Approach #2 because the AP200 has been poorly supported.

Approach #3:
Finally, there is one other (lesser used) option that is based on Approach #2. This option generates a nice formatted report directly to your PC. You can see that one here (along with an example report):
https://www.insideevsforum.com/community/index.php?threads/pc-based-electric-powertrain-report-battery-capacity.12220/

It would be very interesting to see your detailed battery information given the description of your problem.

 

I’d get it to the dealer sooner rather than later.

 

Excellent !
I'm glad it worked for you.

It is interesting that one of your "B" cells does look to be out of character.
The graph goes off the scale - I can re-process the '.log' file in order to re-do the scale if you send it.
You have some evidence that something is intermittant. If it gets into the other state, I wonder if this cell would look different?

Attach the log file it you like and I can re-run a report with a different graph scale.

 

Sorry, I wasn't very clear...

The Powertrain Report tool that you ran reads the data from the car and creates a '.txt' file. Then this .txt file is processed to make the report. You should have a .txt file from when you ran the tool. The name will be coded with the date - As an example, it would look something like this:

SessJava_2022_Feb_23_xx_xx_xx.txt

When you ran the tool, it should have had you save this file somewhere. It should still be there.

 

That cell definitely sticks out like a sore thumb. The "A" bank looks fine.
As for the cell number, I am not certain that our nomenclature matches Honda's. We found the group of cells in the data stream and just started numbering them 1-84.

Re-processed report (attached) shows how far out of whack that cell is. I don't know if it would be worth reading this again right after charging / cell balancing... This set represents a SOC of ~90%.

 

Attached is the re-scaled plot for your 100% case.
I could change this so it auto-scales to the min / max, but that tends to make the scales a little strange. With a 'normal' battery it is not a problem, but one like yours is trickier... The table showing min / max is always right, let me think about plot scaling that will always show the extremes...

 

I changed the Powertrain Report code in GitHub to handle graph scaling a little better...

 

That's the equivalent of finding that the tread depth on your tires has increased since the last time you checked them. Something just doesn't seem right. MrFixit has noted that a few people have 55 Ah or just under, when their car seems to be much too high mileage for that high of a capacity. Leading to the theory that battery capacity can in some cases be reset, although it's not known if this happens inadvertently during software updates at the dealer, or in your case maybe the jump in reported capacity is another system of problems with the HV battery.

 

Thanks for reporting these data, Joe! It would be enlightening if you could post a low SOC report, as well. It looks quite likely that you have a bad cell in Bank B. They shouldn't go that far out of balance unless something's amiss.

 

Yes, my car was recently throwing just about every possible fault in a random fashion. Sometimes, I'd drive it a few hundred feet, and they'd clear. Other times, it would throw different faults after sitting a while. It turned out that the 12V battery was weak. In the process, they did some sort of reset on my car, which made my battery capacity shoot up to higher than the first time I ever measured it. It's floating downwards now, but still higher than the first time I got a reading. So it definitely is possible for the battery capacity value to fluctuate upwards under certain circumstances. I'm waiting to see if it doing some sort of self-calibration, and drops back down to my original range.

 

Interesting... The 'bad' cell does not really show up with the low SOC condition.
It would be interesting to hear from a battery engineer as to what type of failure could manifest itself in this way.

I guess the other consideration is the fact that right now [I think], your vehicle is not reporting failure codes? Obviously, you will probably try to catch some data if / when the failure code(s) appear again.

 

When you say fluctuating upwards I can imagine that might be possible for very small amounts, normally mine only goes down but one time I saw it go up 0.2 Ah. Presumably the capacity test does not always get the exact same result, I remember someone speculating that for that reason it might use an average of the last several tests, which would make sense. Perhaps it gives more weight to earlier results in case the latest test was way off. That would also explain why after a reset back up to 55 Ah it doesn't immediately drop back down to 45 Ah or whatever the first time it does a new capacity check, instead it drifts downwards as repeated tests are done. I'm guessing that in your case it reset to 55 Ah at the dealer but by the time you were able to check it had already dropped some.