Not moving when Drive button is pressed

HV battery really isn't something you should worry about. The symptoms of it failing are obvious, and we haven't seen many failures of it.
Glad to hear. Sort of a clueless question but what's the difference between failure and gradual mileage loss? I'm trying to determine possibly from long-term clarity owners what is the decrease rate one can expect from electric only range?
 
Glad to hear. Sort of a clueless question but what's the difference between failure and gradual mileage loss? I'm trying to determine possibly from long-term clarity owners what is the decrease rate one can expect from electric only range?
A failure would be a cell no longer holding a charge, bringing the whole pack down,a coolant channel or internal pipe rupture, or a failure of the integrated wiring or control modules. Basically any single event that isnt expected, and will bring down the function of the pack significantly, or render it unusable. Cell degrading only reduces the max energy storage, and to a lesser extent input/output capacity, it really wont affect the functioning of the vehicle until it gets *really degraded*, but as far as I know that hasn't happened to anyone here yet.
 
what's the difference between failure and gradual mileage loss?
The warranty is based on the HV battery capacity dropping below 2/3 of the original factory value of 55 Ah.
So, if the capacity drops below 36.6 Ah, warranty coverage would apply.

This could happen suddenly with a failed cell(s), or gradually over time with 'normal' degradation effects.

The warranty specifically excludes salvaged vehicles,
BUT this is a little tricky...
The exclusion does not apply to "Emissions Warranties", and the HV battery is considered an "Emissions Part"

I suspect there may be a battle with Honda in your case if you tried to claim a warranty repair on the HV battery.

Here is a section from the warranty manual which specifies this (highlighted in red):

upload_2024-10-5_18-41-36.webp

I have attached the warranty manuals to this message...
 

Attachments

Anyone have or know of published data showing battery degradation rates over time under normal use?
Re. the clean car extended battery warranty, if the car was sold in a state that offers the warranty, it's covered even if it isn't currently registered there when the warranty is claimed? And if it's a rebuilt title, it is also covered?

Define “normal use”.

What year is your car and what is the mileage? Your battery capacity has declined quite significantly, from 55 to 41.5 in, at most 6 years. While degradation isn’t linear, your battery has a strong potential to reach the warranty threshold of 36.6, if I’m correct.

As to your questions about the warranty, I would advise that you perform your own due diligence as it pertains to your unique situation. It also eliminates the guesswork often provided by other forum members.
 
HV battery really isn't something you should worry about. The symptoms of it failing are obvious, and we haven't seen many failures of it.

I recall at least 2 battery failures among forum members over the past 5 years. The forum membership is a small sample of all Clarity owners, so certainly, other failures have occurred. Not enough to warrant a recall, but it does happen.

In both cases the failure was an individual cell. The fix was a complete battery replacement. Outside of warranty, it is about a $6500 repair.

From someone who seems to worry about what will fail next and has expressed very little confidence in this car and it’s parts, it is somewhat surprising that you show little concern over the HV battery.
 
Define “normal use”.

What year is your car and what is the mileage? Your battery capacity has declined quite significantly, from 55 to 41.5 in, at most 6 years. While degradation isn’t linear, your battery has a strong potential to reach the warranty threshold of 36.6, if I’m correct.

As to your questions about the warranty, I would advise that you perform your own due diligence as it pertains to your unique situation. It also eliminates the guesswork often provided by other forum members.

Similar use is a more appropriate term. Electric only throughout the week (commuting) and hybrid use a couple times a month for longer trips.

It's a 2018 with 74,300 miles.
 
The warranty is based on the HV battery capacity dropping below 2/3 of the original factory value of 55 Ah.
So, if the capacity drops below 36.6 Ah, warranty coverage would apply.

This could happen suddenly with a failed cell(s), or gradually over time with 'normal' degradation effects.

The warranty specifically excludes salvaged vehicles,
BUT this is a little tricky...
The exclusion does not apply to "Emissions Warranties", and the HV battery is considered an "Emissions Part"

I suspect there may be a battle with Honda in your case if you tried to claim a warranty repair on the HV battery.

Here is a section from the warranty manual which specifies this (highlighted in red):

View attachment 23374

I have attached the warranty manuals to this message...

Actually, I don't think "gradually over time is covered". See attached from the 2023 Honda Warranty Basebook.Screenshot_20241005-223714~2.webp Screenshot_20241005-224002.webp
 
Actually, I don't think "gradually over time is covered"

Gradual loss over time is definitely covered if the loss exceeds the warranty threshold of 36.6 Ah within the relevant warranty period of:
  • 10 years, 150K miles in California, Connecticut, Delaware, Maine, Maryland, Massachusetts, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Vermont, and Washington
  • Or 8 years, 100K miles in other states.
This is documented on the last page of the Pre-Delivery Inspection (PDI) checklist (attached).
 

Attachments

Gradual loss over time is definitely covered if the loss exceeds the warranty threshold of 36.6 Ah within the relevant warranty period of:
  • 10 years, 150K miles in California, Connecticut, Delaware, Maine, Maryland, Massachusetts, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Vermont, and Washington
  • Or 8 years, 100K miles in other states.
This is documented on the last page of the Pre-Delivery Inspection (PDI) checklist (attached).

So is that for cars originally purchased in those states or cars that are currently registered in those states? And is it owner-irrelevant so could be a 2nd owner?
 
So is that for cars originally purchased in those states or cars that are currently registered in those states? And is it owner-irrelevant so could be a 2nd owner?
My understanding is that it applies wherever the vehicle is currently registered. It probably applies to the current owner, but I am not sure about that.
 
Similar use is a more appropriate term. Electric only throughout the week (commuting) and hybrid use a couple times a month for longer trips.

It's a 2018 with 74,300 miles.

Here’s the chart for that situation. IMG_3632.webp
This figure shows the degradation of a lithium cell that is different from what is used in the Clarity. It is what was observed and measured under specific laboratory conditions. None of us will operate our vehicle in the wild, under those same conditions. That said, the curve gives us a reasonable estimate of what to expect from a lithium battery. Obviously, someone subjecting the battery to conditions wildly different from those used in the laboratory, will get different results.

We have no history on your car. We do know that the battery capacity has decreased about 25% over a 6 year period and would need to decrease another 11-12% over the next 2-4 years and/or 25K-75K miles, depending on the emissions warranty, if applicable, in order to qualify for a replacement under warranty. We can only speculate on where your battery is on the curve. I’d speculate that it is in, or near, the Saturation Stage.

If it were my car, and I confirmed that it would be covered under warranty, I would not be inclined to baby the battery for the duration of the warranty period.
 
Here’s the chart for that situation. View attachment 23380
This figure shows the degradation of a lithium cell that is different from what is used in the Clarity. It is what was observed and measured under specific laboratory conditions. None of us will operate our vehicle in the wild, under those same conditions. That said, the curve gives us a reasonable estimate of what to expect from a lithium battery. Obviously, someone subjecting the battery to conditions wildly different from those used in the laboratory, will get different results.

We have no history on your car. We do know that the battery capacity has decreased about 25% over a 6 year period and would need to decrease another 11-12% over the next 2-4 years and/or 25K-75K miles, depending on the emissions warranty, if applicable, in order to qualify for a replacement under warranty. We can only speculate on where your battery is on the curve. I’d speculate that it is in, or near, the Saturation Stage.

If it were my car, and I confirmed that it would be covered under warranty, I would not be inclined to baby the battery for the duration of the warranty period.

Thanks for that info! Would you say the best place to go to ensure that it's going to be covered under warranty is my local Honda dealer?
 
Would you say the best place to go to ensure that it's going to be covered under warranty is my local Honda dealer?

The dealer would be a good place to go to determine whether or not Honda will honor the warranty for your specific situation. It won’t necessarily “ensure that it’s going to be covered”.

I’d recommend that you bring copies of the warranty, your purchase paperwork and a letter for an authorized person at the dealer to sign which would acknowledge that your vehicle will be covered under warranty, should that be their decision. That way you won’t have to go through the motions again should they change their minds between now and when you may need to have the battery replaced.
 
The dealer would be a good place to go to determine whether or not Honda will honor the warranty for your specific situation. It won’t necessarily “ensure that it’s going to be covered”.




I’d recommend that you bring copies of the warranty, your purchase paperwork and a letter for an authorized person at the dealer to sign which would acknowledge that your vehicle will be covered under warranty, should that be their decision. That way you won’t have to go through the motions again should they change their minds between now and when you may need to have the battery replaced.

So the two documents that Mr fixit attached above:
2018_Honda_Warranty_Basebook_AWL05251_Hybrid_Version.pdf
2018 Clarity Plug-In Hybrid Emission Warranty Parts List.pdf
And when you say purchase paperwork do you mean proof that it was purchased new in a certain state (so that the extended warranty can apply if that's how it works?) or my own more recent used purchase docs? Luckily, both of our Claritys were sold new in California and both will registered in Maryland if a warranty claim is needed so hopefully we're covered either way. One has a clean title though and one will have a rebuilt so it'll be interesting to see if that matters.
 
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