Battery Capacity Test Reports - Ongoing data for warranty

Cash Traylor

Cash Traylor

Well-Known Member
Greetings all,

This forum has covered the HV battery warranty and other discussions at length and I did not want to duplicate that here. A few posts have been sporadically placed where owners went back after purchase (the dealer PDI failures) to get the capacity checked. I wanted to make a very short post here about my trends, and thought others may be able to post as well. There is value even if the data is non-standardized (year model, total miles, driving conditions and style of driving, versus calendar age in service) and goals. My goal is to have the battery fail at 7 years and 11 months and under mileage (which with my little driving will not be a problem! ;-) I "plan" to get an analysis report at least once a year from now on.... So for the first data set:

Car Info: 2018 Clarity PHEV Touring, DOM 10/2017, placed in-service 06/2018: PDI report acquired later (thanks to this forum as the dealer didn't do the PDI and I know the car sat uncharged while on display, thankfully inside the dealership). Almost exclusively charged using the included level 1 charger overnight. Operated in Dallas, Texas - so yeah - hot, and mixed driving (city/hwy) about even, and have to admit to lead foot.
  • 1st analysis was 12/2018 (6 months after taking delivery), 3750 total miles half on HV to break-in the ICE: Battery Pack Capacity 53.8 Ah (~98%)
  • 2nd analysis was on 2/2020 (20 months of ownership), 13325 total miles, now mostly EV mode to range extend mode: Battery Pack Capacity 49.6 Ah (~90%)
I get a new battery if it drops below 36.6Ah or 66% capacity. Well, I have lost 10% in less than 2 years, 6 years to go. So, extrapolating would put it at 60% at 8 year. Unfortunately that isn't really how these batteries age, it's not linear - but I will cross my fingers one way or the other.

Cheers,
Cash
 
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Capacity measurement is sooooo much better than range estimates. A lot of EV batteries have shown a pattern of loss at the beginning and then the rate flattens for many years.
 
Cash Traylor said:
Greetings all,

This forum has covered the HV battery warranty and other discussions at length and I did not want to duplicate that here. A few posts have been sporadically placed where owners went back after purchase (the dealer PDI failures) to get the capacity checked. I wanted to make a very short post here about my trends, and thought others may be able to post as well. There is value even if the data is non-standardized (year model, total miles, driving conditions and style of driving, versus calendar age in service) and goals. My goal is to have the battery fail at 7 years and 11 months and under mileage (which with my little driving will not be a problem! ;-) I "plan" to get an analysis report at least once a year from now on.... So for the first data set:

Car Info: 2018 Clarity PHEV Touring, DOM 10/2017, placed in-service 06/2018: PDI report acquired later (thanks to this forum as the dealer didn't do the PDI and I know the car sat uncharged while on display, thankfully inside the dealership). Almost exclusively charged using the included level 1 charger overnight. Operated in Dallas, Texas - so yeah - hot, and mixed driving (city/hwy) about even, and have to admit to lead foot.
  • 1st analysis was 12/2018 (6 months after taking delivery), 3750 total miles half on HV to break-in the ICE: Battery Pack Capacity 53.8 Ah (~98%)
  • 2nd analysis was on 2/2020 (20 months of ownership), 13325 total miles, now mostly EV mode to range extend mode: Battery Pack Capacity 49.6 Ah (~90%)
I get a new battery if it drops below 36.6Ah or 66% capacity. Well, I have lost 10% in less than 2 years, 6 years to go. So, extrapolating would put it at 60% at 8 year. Unfortunately that isn't really how these batteries age, it's not linear - but I will cross my fingers one way or the other.

Cheers,
Cash
Click to expand...

Very good information - thanks for posting @Cash Traylor !
Are you able to post pdfs of the full results if you have a copy? I am interested in some of the tedious data as well.

Does anybody else have their data that they are willing to post? Thanks!
 
Good idea Ray,

I wanted to limit the number of posts to just a basic report of test results from other owners without much hypothesizing. However your request for the reports makes a lot of sense for another reason that occurred to me. We really do not know the matrix that the BMS is using to collect this "valuable" statistic (since it is what our warranty is based upon) nor the software code that may be "tweaking" it. Battery capacity is very relative to temperature (not just the use of a heater etc, but the temperature of a cell directly effects its chemical energy storage capacity. The assumptions is that the BMS is using a common Coulomb counter and chemistry and OEM set voltage curves. That being the case it is unknown to me, if the BMS accounts for battery temperature (the battery capacity variation over temperature ranges can be interpolated but is generally only accurate when "new). Now I digress...

The reason I mention the above is really simple. I am VERY curious if anyone has any consecutive but off season (summer to winter, etc.) reports run that show a statistically significant INCREASE in battery capacity?!? Yes, come this summer when it is 104 degrees outside I am going to get another report run just to see. My tests are oddly during very similar environmental conditions (outside & inside temps are identical and coolants were close, yea spooky and could not have done that if I tried). I have an "older" but low mileage Clarity. Wonder what the battery trends on "newer" but higher mileage ones look like? Range is unimportant here.

Oh, and if anyone wants to see one of these batteries that hasn't: https://www.insideevsforum.com/community/index.php?threads/clarity-battery-teardown.6062/

Anyone else like to volunteer some test data?
 

Attachments

Bookmarked this thread to see if it's updated.

I haven't conducted a PDI capacity test or whatever it's called but I have noticed a drop in my EV range guess meter and it's a bit concerning.
At the same time last year I was getting low 60s and now I'm getting high 40s. Temperatures are about the same (Florida) at this time of the year and my commute/driving habits have not changed. I have owned the Clarity for one year (purchased last January) and I'm about to hit 20,000 miles.
Hopefully more people share their data.
 
Ok, this is completely my fault because my first post was not clear and wondered around trying to explain what I was trying to accomplish in this thread. Range has been addressed to the point of the dead horse in other threads. What I wanted to try to accumulate here, was actual data report numbers. The ONLY NUMBER that matters in respect to our PHEV is the battery CAPACITY, not range, it simply does not matter. The on board BMS HV Battery Capacity (from 55Ah down to 36.6Ah as far as "good" goes) is the only number Honda will honor when it comes to the electrical performance (range) of our vehicles. So, this is the statistic I wanted to have gathered. Anecdotal info to go with it that is relevant, such as the vehicle's date of manufacture, date of sale (placed in service), and current mileage, are all good data points to tie to any reports. Including a copy of the actual computer printout from the dealer is also very helpful (not my idea, thank you #Ray B).

If you have these reports please contribute. If you do not, then I would recommend that you refrain from posting here, and occasionally get them. It is what your 8-10 year, 100K mile warranty on your battery is based. Also, Honda dealerships will NOT check this for you as it is not on any scheduled maintenance inspections that I have found, AND amazingly (from Honda's PDI) our cars will NOT flag a DTC or MIL for a battery back that is under it's warranty capacity! Only if a cell has critically failed and the pack is unable to balance or the BMS cannot maintain charge integrity (that is something like under 25%, see attached). So to keep this in perspective, your battery would be subject to warranty (period) replacement if under 65% rated capacity at a OWNER REQUESTED capacity check (less than 36.6 Ah). However the car will not flag a "HV battery deterioration" until below 25%... does anyone else see a problem with this. The OWNER is responsible for tracking their battery performance if they want to be assured of warranty. I lost 10% in less than 2 years and 13K miles. Likely not a problem, unless the dealer really mistreated my battery and it sat uncharged on the lot from 10/2017 to 6/2018 when I bought it with 104 miles on it. Just offering an example... Please read attached. However I don't want to get into discussions on it, just data in this thread, so it remains historically valid over time.

Cheers,

Cash
 

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The Clarity PDI was supposed to be done when you purchased the vehicle. Most were not, as the dealers simply didn't speak Clarity PHEV yet (some still don't). If you didn't get the PDI it is attached above, print it out and go demand it, as it was a requirement from Honda to the dealer for sales. You may be missing something else, who knows. As to answer your question, I have had two tests, first the PDI, which I had to go back for months later when I learned about it from this forum, and the second one during a regular service. I was charged for neither. I do not know if they will charge you an hourly rate if you just bring the car in for just this report. It takes literally 3 minutes, and if the dealer is good can even do it right on the service line while you wait (although you may not get a print out that way, maybe take a picture of the techs laptop screen). They hook their computer up to the ODB Port, launch their software and it is displayed right there, takes absolutely no more time than that. My recommendation to everyone is that since the Clarity maintenance procedures almost always dictate plugging their computer in to check for DTC/MIL codes, just have them print the report for you each time you bring it in (part of the multi-point inspection, that is "included"). The trick is they will likely not do this UNLESS you ask for it. Since the HV battery is what makes your Clarity a PHEV and not a hybrid, and your warranty is tied directly to this (amp hour) number, that the car will not tell you if it is below warranty, why not? I take my car in for service, so far, about once a year - once a year battery checkups seem reasonable regardless of cost.

Cheers,

Cash
 
Copying from a previous posting in another thread. Bought our PHEV 5/21/2018; the PDI report we got didn't include battery capacity. Had the capacity checked on 10/24/2019 with 18,321 miles on the car, result was 51.7 Ah.
 
Yes, the recommendation to get a battery capacity test done yearly was made in other threads and is wise, particularly after 3-4 yrs of normal usage (or sooner in extreme temp environs) since the dash indicator for a HV battery issue won't trigger at the warranty level but at a much lower level. Unless you buy a used model and have not become one with the car yet, you will be aware of significant losses of range over the seasons.

Vehicle Mfg 10/2017, purchased 12/2017, no PDI report provided. My only datapoint: 2019-04-19 Mileage 19k ( est 9k EV miles), charging 99% by 120V. Test performed at dealer: 52.9 Ah.

Other threads on this topic:
https://www.insideevsforum.com/comm...eading-the-battery-pack-capacity-signal.3007/

https://www.insideevsforum.com/community/index.php?threads/battery-capacity-test-results.5836/
 
Well, this thread died horribly.... However, I have changed paths with the recent covid deal, and few people going to the dealers or getting BCT's. Seems the BCT and the PDI are elusive data.

https://www.insideevsforum.com/comm...g-android-app-car-scanner-from-0vz-only.8708/

Please see this request here if you are interested in participating.

One note for anyone that runs across this thread, or others about HV Battery Capacity / EV Range, etc. If you are on a lease and considering acquiring the car, or are considering buying a previously owned Clarity, please do yourself a favor and get a Battery Capacity Test prior to acceptance of the vehicle. This is the one data point that matters regarding your available warranty on the battery pack. A few years from now I can see these cars hitting the market used and dealers offering great buys. They do not check this automatically as part of any published Honda multi-point "pre-owned" delivery schedule that currently exists. You could walk out owning a car with 25% or more battery loss, and never know it. Warranties like this are money on the table for the used market.

Cheers,

Cash
 
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