My HV Battery Warranty Replacement Experience

Yeah I have bad luck with batteries lol.
My concern here is my usage of the Clarity has also fallen off to almost non-use so my fear is with the pack sitting idle cells have hade time to drift out of balance.
Prior to current gen Soul EV they really struggled in similar environments as the Leaf. The Soul was an air cooled pack with cabin air from the car.
To replace the Soul we got a Niro EV. Kia went a step further with it than even Honda and the liquid cooled loop can be chilled by the ac system.

 

My goodness, info is way over my head but I am impressed. How do you even check ah levels, cell voltage/mV, State of Charge (SOC) data, battery capacity & spread between paks, etc. How do you trickle charge your 12V? Never heard of Car Scanner. / I only know the % of charge on my EV. I currently drive a 2022 Chevy Bolt leased in Aug 2021, with a recalled battery waiting to be replaced— may do Lemon Law if not replaced soon. Previously, had a Hyundai Kona that was recalled and turned in under the CA Lemon Law. Anyway, is it important for me to know all this battery stuff?

 

Some on this forum believe you can extend the life of your battery by never charging it above 80% of its capacity. However, Honda didn't provide a simple way to limit the percentage of battery charge, so they were not promoting that strategy. Honda realized that most people just want to get in their car and drive, so they implemented battery management software that protects the battery--at least long enough to get through the warranty period.

If you want to learn all about how you can check your Clarity's battery capacity, read this lengthy thread: Budget Battery Capacity Readout

 

For Suzanne- Perhaps to add "Clarity" - horrible pun, I know: So yeah, you can ignore all of the battery stuff and happily just drive your car. *If* you are interested some members of this forum (i.e. MrFixIt) have done a lot of work and research to share, and even started a community "report" of battery findings. i.e. Amp hours over time and the like based on input from multiple Clarity owners. But no, you don't have to track on this at all to enjoy your car.

 

Hello Anthony, I am having a similar problem today. After a brief charge in a public charger, multiple warning lights came on in my clarity. I had to do a few on and off to start the car and manage to drive it home. With 120v garage charger, the car is charged to 100% at home with only 18 mile range - very likely one of the battery packs failed. I'd like to know how you did the battery read out (hardware and software?). I want to try it myself before bringing it to the dealership. Thanks!

 

@bigbug,
See this post for the ways you can check battery capacity:
https://www.insideevsforum.com/community/index.php?threads/2018-honda-clarity-level-2-charging-problem-fyi.13814/#post-169692

 

Trickle charging or maintaining a 12V battery can be accomplished with a Battery Tender or similar device.

In my opinion, No.

If the battery fails, usually just one cell, the car will need a new battery and it won’t matter if you know which cell failed. If collecting and analyzing this sort of data fascinates you, then it may be important for you to know all that stuff.

Again, just my opinion, the only data point worth monitoring is EV range under repeatable conditions. It is a low tech, seat of the pants measurement. If a decrease in range of 20% is observed, the battery has probably lost 20% of its original capacity. Alternatively, with an appropriate EVSE, the amount of energy (kWh’s) that the battery will accept during a charge can be measured. A decrease from new, would be an indication of reduced capacity.

We’ve had our Clarity for almost 3 years. Initially I recorded EV range and remaining range on every drive. Then I decided it was a waste of my time. Now we just plug it in, let it fully charge and just drive it.

 

Thanks MrFixit, much appreciated!

 

Huge thanks to MrFixit for his app, I am able to pull the HV battery information:

HV Battery Voltage A: 314.9V
HV Cell Max SOC A: 64.22%
HV Cell Min SOC A: 63.71%
SOC: 59%

HV Battery Voltage B: 314.9V
HV Cell Max SOC B: 24.1%
HV Cell Min SOC B: 22.54%

HV Battery Capacity (A+B): 23.24ah
HV Battery Capacity A: 0.44ah
HV Battery Capacity B: 22.80ah

Input Voltage of Normal Charger: 3.4V
Output Voltage of Normal Charger: 315.4V
Charging Voltage Target: 4093.8mV
Current Limit during Plug-in Charging: -201.9A

Cell Statistics, mV:
min max delta avg
Bank A 3753.0 3758.4 5.40 3755.3
Bank B 3537.8 3548.8 11.00 3543.6

A Bank Cell Voltages, Cells 01-84 (mV):

01 3756.6 3758.2 3755.4 3756.6 3754.8 3756.0 3756.0 3755.6 3756.4 3754.8
11 3757.0 3755.0 3753.8 3756.0 3758.4 3753.0 3756.0 3757.0 3754.8 3756.4
21 3753.8 3755.6 3753.6 3755.0 3755.6 3756.0 3755.6 3754.2 3755.4 3756.6
31 3756.4 3754.2 3756.0 3754.4 3757.2 3755.6 3754.4 3756.4 3754.4 3755.4
41 3754.2 3754.8 3756.0 3755.0 3753.6 3754.8 3753.0 3757.0 3756.0 3756.0
51 3756.6 3754.8 3755.4 3756.4 3755.0 3753.2 3755.6 3754.8 3754.4 3756.0
61 3754.8 3756.4 3754.4 3755.0 3755.0 3755.6 3753.6 3755.0 3755.4 3755.4
71 3754.2 3756.0 3755.4 3754.4 3754.8 3754.8 3754.4 3755.6 3753.8 3754.8
81 3754.8 3753.6 3755.4 3756.4


B Bank Cell Voltages, Cells 01-84 (mV):

01 3544.0 3542.4 3543.0 3544.6 3541.8 3543.0 3543.0 3544.0 3543.6 3544.2
11 3543.6 3544.2 3547.6 3544.0 3548.8 3546.4 3546.4 3544.2 3544.6 3546.6
21 3546.6 3545.4 3546.0 3547.0 3542.6 3543.6 3540.2 3541.2 3543.2 3542.4
31 3542.6 3543.0 3542.4 3541.8 3544.2 3542.0 3539.0 3537.8 3540.8 3540.2
41 3542.0 3541.8 3540.2 3540.6 3540.0 3540.8 3543.0 3539.0 3548.2 3545.4
51 3543.6 3544.2 3547.6 3545.8 3547.2 3546.0 3542.4 3544.8 3543.6 3542.0
61 3544.8 3541.8 3544.6 3542.0 3543.2 3542.0 3542.6 3541.8 3542.0 3541.8
71 3543.6 3542.6 3547.0 3544.8 3544.0 3544.0 3545.2 3546.4 3543.6 3544.2
81 3542.6 3545.2 3546.0 3544.6


I'm no expert to the parameters. In my first glance it seems the HV battery A is dead (capacity = 0.44ah). But why it has a higher SOC than B? (64.22% vs 24.1%), and higher voltage in each cell?

Update: after charged for about 30 min, battery A SOC became like this:

HV Battery Voltage A: 323.1V
HV Cell Max SOC A: 73.54%
HV Cell Min SOC A: 72.89%
SOC: 73%

But B SOC stays at 24% and 22%, and A capacity also stays at 0.44ah. Also note that since the multi error warning appears, the max range of the car dropped more than 50% to about 20 miles. Please help interpret the numbers. Appointment is booked with Honda dealer tomorrow. Will see what they say about it.

 

Here are my thoughts -

I kind of expected to see a bad cell, but all the cells in each bank are within character of each other.

This leads me to believe that the problem is not the battery / cells themselves, but rather something with the charging / BMS system.
It doesn't really matter because the charging systems are integrated into the battery assembly and I believe that Honda will have to replace your HV battery.

I'm sure you will let us know whatever details they find, but my bet is that you will be getting a new battery.

 

Battery A is toast. Could be just one bad cell out of 84.

A and B are wired in parallel. That arrangement keeps voltage the same while doubling capacity (aH’s). You’ve lost half the capacity.

 

Had to reschedule the appointment to next week due to change of plan. In the mean time I managed to pull the error codes from the ODB reader:

P0bbd
P157c
P0b0e

I can only find generic explanation to these codes, but not specific to Honda Clarity. All of them point to HV battery related issue. I agree with you it looks more like sensor and/or circuit problem.

 

@pigrew - Do you have any insight into these specific codes?

 

Reporting back on my Clarity problem: miraculously, all warnings and error codes are gone, and battery readings are back to normal after 6 days. Here is the timeline:

First 4 days: all warnings, battery readings, max EV range stayed the same 20 miles. charged to full at home every day;

Day 5: Max EV range shows 27 miles after overnight charge. All warnings are gone, but engine light is still flash, same 3 error codes. Battery A and B readings are back to normal.

Day 6: Max EV range shows 35 miles after overnight charge. Engine light still flashed first time start the car in the morning. But after driving for a while it turned off by itself.

Day 7 (today): Max EV range shows 47 miles this morning. Engine lights is gone. Everything is back to normal.

Guess I can't get a new battery from Honda anymore....

 

Yikes - it sure seems like you have a problem there... Maybe it's intermittent, but it obviously could return.
It would have been very nice to have had the dealer observe the problem while it was present so they would have it on record.

Hopefully this was a one-time anomaly that is gone forever, but if not, that's why there is a warranty.

 

Yup I am worrying the same. Will take battery readings more often.

 

Yes, in the wisdom of Microsoft Word (even before the prescient Clippy):