Budget Battery Capacity Readout

Hobbesgsr said:
My 2018 Clarity (~159,000 km...1,000kms away from the battery warranty expiry) just popped up a CEL and POWER SYSTEM warning on through dash. Connected to OBDII and codes P1DC7 and P0A7F came up (Hybrid battery pack - deterioration). Brought it to the dealership and 2 days later, they said they cleared the codes and come back if the error reappear. They stated that's Honda SOP.

The weird part is the battery range is much higher and battery capacity jumped from 42Ah, measured a few weeks ago, to 55Ah. Thanks to your post, I'm waiting for this to stabilize.
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The dealer is trying to pull a fast one on you and they may succeed. They should have provided, or you should have asked for, a battery capacity reading prior to the codes being cleared. They’ve reset the codes, which reset the capacity reading and there’s a good possibly that the code won’t appear again until after you’ve exceeded the warranty period. Honda SOP “Screw the customer”.
 
Landshark said:
The dealer is trying to pull a fast one on you and they may succeed. They should have provided, or you should have asked for, a battery capacity reading prior to the codes being cleared. They’ve reset the codes, which reset the capacity reading and there’s a good possibly that the code won’t appear again until after you’ve exceeded the warranty period. Honda SOP “Screw the customer”.
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I wasn't worried about the battery capacity since that was within the battery warranty range. I did ask for a copy of the diagnostic printout with the odometer reading and the fault codes. Plus the rep promised to keep the service ticket open even if the odo goes past 160k; whatever that is worth.

I hope that within the next 1000km, I can get enough full charge cycles in.
 
I got all the same codes with 46ah capacity. Just changed my 12v battery and it went away. That's probably your issue.

My battery would read around 11.8-12.1v with the car off..... Think the system freaks out if it's not holding charge right.

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Conelite said:
I got all the same codes with 46ah capacity. Just changed my 12v battery and it went away. That's probably your issue.

My battery would read around 11.8-12.1v with the car off..... Think the system freaks out if it's not holding charge right.

View attachment 27633
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There’s more information available about those codes than what your fault log manager displays. They indicate a more serious condition than a weak 12V battery and replacing the 12V battery is not on the list of proposed solutions.

Codes don’t always pinpoint a problem but a good first step is to have them read and properly diagnosed by a dealer. The DIY code readers rarely proved the level of detail that a dealers reader provides.
 
Conelite said:
I got all the same codes with 46ah capacity. Just changed my 12v battery and it went away. That's probably your issue.

My battery would read around 11.8-12.1v with the car off..... Think the system freaks out if it's not holding charge right.

View attachment 27633
Click to expand...
Thanks for the suggestion but I have a ScanGuage permanently mounted and set to monitor LV battery voltage and RPM. Voltage reads 12.8V resting and 14.6V on.
 
Update: After the dealership ECU reset on Nov 24-25th, I drive and charged as usual and very slowly the range guess-o-meter started dropping. Last week, the car went over the the battery warranty (160,000 kms) and the range dropped back down to the usual 40km (~25 miles) range in the winter. Its been in the -5 celsius range lately.

Well, tonight the CEL and Power System warning light reappeared. I'll bring it to the dealership tomorrow morning hoping that the service advisor kept his promise to keep the work order open with the pre-battery warranty expiry odometer reading.
 
Update 2: After dropping off the car, the dealership called a few hours later that they will replace the HV battery under warranty. :D They are checking availability and will let me know when to drop off the car which will take approx. a day to complete the job.

Hope it wont be back ordered for 2 years like that YouTube vid @Lonewarrior posted.
 
Returning (intentionally) to an old thread. I end up reading my old posts to see how my traction battery has done over time. My last post in this thread I think was #687 (partly quoted below). That was Feb 2025. It's now early January 2026. Did the reading again, got 43.02, so a little better than I predicted last year. I did, hopefully correctly update the spreadsheet this time.

The car has been OK, but started doing something different this winter. That is it now easily goes to 0.0 charge (in 22 miles), but the bad part is the EV "bars" go to 0. This is abnormal, as the car's EV bars should stay at 2, and do HV mode automatically. If I let EV go to 0, I get strong angry bees sound once again. Resetting the car by disconnect/reconnect the 12v battery didn't work as it has to reset things in the past. I now have to pay more attention and never let EV range go to zero (more than in the past). The engine groans if I do it accidentally, and it smells hot. I did check the oil etc. and its spot on. Hopefully, I can train myself to avoid 0 EV better. It's gotten a little harder now that EV range is only 22 miles. Oh and I'm at 86,711 miles now.

Part of my post from last year follows:

"My Clarity is 80K miles now, with 44.3 ah reading. We're just beginning 2025, so I figure I have about 4 years to get to warranty zone (or not). 2025 this year, 2026, 2027, 2028 until purchase date? -- I purchased September 2018. My rate of loss is 1.5 ah per year which has been very consistent since I first got the car..."
 

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