Budget Battery Capacity Readout

CIvan said:
When I purchased my Clarity used 3.5 months ago with 12K miles, the battery capacity was 55.06 Ah
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We have had several cases where I feel like the reading is unrealistically high.

Your initial measurement seems like one of these unusual cases because it is hard to believe that one could have NO degradation at 12K miles.
As you say, you have no knowledge of what the original owner's behavior was.

It would be surprising if they were some kind of technical wizard and knew exactly what to do in order to preserve capacity.
More likely, they did something much less intelligent - like never charging at all and just operating as a hybrid (with 2 bars on the gauge), would that preserve full capacity? I dunno, but I kind of doubt it.

It will be interesting to follow your capacity going forward. Thanks for participating !!

I keep thinking maybe there is some obscure way that the battery capacity gets "reset" back to a factory setting, and then takes a while before it again converges on the actual value. I have no proof of this of course.
 
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CIvan said:
One of the things that is most interesting to me is preserving battery capacity for the long run. From my research, the most damaging things to batteries are: 1) excessive heat, 2) draining to 0%, 3) charging to 100%, 4) charging at a high current and 5) discharging at a high current.

When I purchased my Clarity used 3.5 months ago with 12K miles, the battery capacity was 55.06 Ah as measured by my Vgate OBD II scanner. I have no idea how the car was used / charged / stored before I bought it, but I thought that number was rather spectacular. Since then, I have driven roughly 2.5K miles (about 1K electric), and my battery capacity has dropped to 54.55 Ah.

I have kept the car in a garage to avoid heat soaking, the BMS handles the min and max of the battery pack, I only charge on level 1, and I never drive hard in electric mode, yet my capacity has dipped .5 Ah since I bought it. It doesn’t look like the previous owner suffered hardly any degradation! I would love to know what they did to keep it so high. Maybe they never charged it at all and only drove it as a hybrid??

Anyway, I put my information in the group spreadsheet and continue to look for ways to maintain battery capacity...
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Pretty much the same stuff, but I think these are things to avoid for longer battery life.
-Heat (I avoid charging while hot if I can. JuiceBox Pro has a charge delay feature in the app. Yes, I know there is active cooling but nobody knows how effective it is)
-High voltage levels above 4.1V/cell (Can control somewhat by being diligent and if usage fits your needs, time the charging so it finishes your desired charge level before you drive)
-Excess current (over 100A? for long duration? I think it's safe to charge at 240V @ 32A max current for PHEV everyday.)
-Low voltage levels (battery management takes care of this and you can't get it to too low so no worries here)
-Age (can't avoid)

Some data I collected:
100% reported on HondaLink is actually around 90% of per cell capacity.
Voltage comes from string of 84 cells. (2 string in parallel)
99% is 342.3V / 84 = 4.08 V/cell
80% is 327.9V / 84 = 3.9 V/cell
60% is 314.6V / 84 = 3.75 V/cell
14% is 297.5V / 84 = 3.54 V/cell
Engine kicks in when lower than 13%, the per cell is 3.54V/cell


I read that high current can degrade the battery as well, but then normal driving is also considered high current. As long as the charge is lower than normal driving, I think it should be okay. Just my opinion, and that's why I think charging at 32A (at 240V) is not an issue unless the coolant temperature is hot.
6.6kW charging / 240V = 27.5A. Personally I set my JuiceBox Pro 50 at 24A. When I'm in a hurry, I change it to 32A through the phone app. I can get about 20% charged within 30 minutes when at 24A rate. The JuiceBoxPro app is pretty handy for me as I usually set it to charge 20% at a time which will keep my top battery level around 60%-70%.

Driving current can go past 230A without starting the engine (first major notch is about 30A, 2nd 60A, 3rd 120A, 4th notch at 12 o'clock position 180A). Cruising on a flat highway was around 60A. Regen current on a downhill can be high as -100A without touching the brake pedal. Touching the brake pedal lightly, regen can go up to -170A without friction brake kicking in.


Lot of stuff to read on here:
https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries

"every reduction in peak charge voltage of 100 mV/cell is said to double the cycle life."
"every 70mV reduction in charge voltage lowers the overall capacity by 10 percent."
"optimal charge voltage is 3.92V/cell. Battery experts believe that this threshold eliminates all voltage-related stresses"


By the way, if depth of discharge is the only factor, even if we use 1 full cycle every day (from 90% to 15%) which is 17k miles/year, the difference wouldn't be that much. It's like asking after 10 years would you be okay with 86% battery left instead of 88% battery?
I can see why people might choose not to baby the battery. I do baby the battery by the way :)
My thought is that other variables (heat + high voltage levels) must also play a big role. I want the battery to be in top condition so I will continue to baby the battery. My iPhone SE 2020 has over 200 cycles but it still shows 103% capacity. I've been keeping it below 70% most of the time.
 
Hoon said:
I want the battery to be in top condition so I will continue to baby the battery
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It seems a little bit ironic if you consider this -
By 'babying' the battery, you may be prolonging the life, but you are in essence settling for a lower capacity all along (by intent).
Is that really any different than not not babying the battery, utilizing 'full' capacity, and accepting that the capacity will drop some over time ?

Because of Honda's buffering that you described, nobody ever uses the "full" capacity beceuse the BMS doesn't allow you too. It's just a matter of degree, and choosing to use less than what Honda permits.
 
I just purchased a 2018 base model with 70k miles on it. I purchased a wi-fi Vgate scanner and found that my max capacity is currently 47.82kwh. Looking at the google sheet, it seems about average.
 
MrFixit said:
It seems a little bit ironic if you consider this -
By 'babying' the battery, you may be prolonging the life, but you are in essence settling for a lower capacity all along (by intent).
Is that really any different than not not babying the battery, utilizing 'full' capacity, and accepting that the capacity will drop some over time ?

Because of Honda's buffering that you described, nobody ever uses the "full" capacity beceuse the BMS doesn't allow you too. It's just a matter of degree, and choosing to use less than what Honda permits.
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By babying the battery I can take advantage of the healthier battery when needed. I think that’s the only advantage there is. Oh, and maybe when time comes to sell the car it might be a easier sell. Babying the battery is only applicable if it fits your drive habit. If my commute were 20+ miles one way (my current commute is 11 miles) I’d probably just charge to 100% all the time or time it to finish just before driving.
 
I fought it a bit but finally saw the readings I wanted. My Clarity is a 2018 with about 39.3k miles on it.

Question - I bought this mainly just to check my battery capacity, but it seems like many are leaving this plugged in. Benefits to that? And what sensors are you guys watching that do leave it plugged in?

IMG_9600.webp
 
Very nice !
Thanks for joining is in this important characterization process.

Please consider entering your data in the shared spreadsheet here:
https://docs.google.com/spreadsheet...OQIpT_YiGp9N-vnBOiSz96C2I/edit#gid=1710145002

I would be happy to help if it's not completely clear.

Regarding leaving the OBD2 device connected - I, like you, did this primarily for the capacity readout. I do not leave it connected, and just plug in every month or two to monitor the capacity. If you do find something interesting that you would like to monitor more regularly, you probably saw that the OBD device will power off unless you choose to override that 'feature' as described earlier in the thread.
 
stacey burke said:
Just put mine on the scanner - seems a bit high. 2018 with 30,000 miles
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Indeed...
You are not the only one who has an exceptionally high number.
We are trying to understand why there are some with very little degradation. Can you provide some details about how you operate? Are your miles mostly HV or EV? How often do you charge?

I put your basic measurement in the spreadsheet. Feel free to add some of the additional information.
 
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I leave my OBDII connected most of the time I am driving, with phone in holder on dash.

I am displaying Engine RPM, Coolant temp, Battery SOC, MPH, % Load, Spark timing.

My system also records these to a file.
 
ClarityBill said:
I leave my OBDII connected most of the time I am driving, with phone in holder on dash.

I am displaying Engine RPM, Coolant temp, Battery SOC, MPH, % Load, Spark timing.

My system also records these to a file.
Click to expand...

What device do you use and what app?
 
MrFixit said:
@Fast Eddie B
Although I am not close enough to run a check for you, I am more than happy to assist you in getting your own setup running.
This thread has gotten a little cluttered, so if you have any doubt / questions as to how to proceed, feel free to send me a PM and I can walk you through it. It may appear more challenging than it really is.
Click to expand...
Hey I just picked up a vpro from ebay for $20 should be here in a few days, can you give a quick guide here on how to get everything working?
 
dnb said:
can you give a quick guide here on how to get everything working?
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* It has been a long time since I started from scratch.
Do me a favor - When you go through this, pay close attention and post any corrections to this procedure which I am trying to recreate from memory

Here is a basic guide:

1. Purchase the Vgate iCar Pro OBD2 adapter
2. Install the Car Scanner application on your phone.
  • Upgrade to the Pro version of Car Scanner (I think it is ~$4.95)
3. Plug the Vgate adapter into your vehicle's OBD2 port, Start the vehicle.
4. From your phone, find the Vgate adapter under Bluetooth settings and "pair" it with your phone.
5. In the Car Scanner App, go to Settings (the gear in the upper right).
  • Choose "Vehicle Option"
  • Select "Choose Connection Profile"
  • Browse to "Honda", then "Clarity PHEV"
6. Back out to the main menu and touch the large green Connect button. Car Scanner should acknowledge a connection to your vehicle.
7. At this point, you can select "All Sensors" and you will see a long list of values...
  • Scroll down the list until you get names that start with [Clarity]. These are unique to your vehicle.
  • Of highest interest to most is "[Clarity] Battery Capacity (total)"

* Note 1 - As discussed in detail in this thread, the Vgate adapter has a power saving mode and it WILL shut down after 30 minutes of inactivity. The only way to turn it on again is to unplug and re-plug it. Turning the car off does NOT wake up the adapter. If you use it regularly and want it to stay on, then you must execute a command described in post # 42 above.

* Note 2 - I will not offer a tutorial on how to use the more aesthetically pleasing aspects of Car Scanner (Dashboards, data recording, and such). You can learn these on your own, or read through this thread carefully and you will find some examples posted by us and others. @Hoon has posted a very nice Dashboard that you could learn to use if you want.

* Note 3 - Also, as discussed in the thread, the Clarity PHEV profile from Car Scanner is not 100% current. There are a few parameters that we found that have not been provided to the Car Scanner developer at this time. We posted load sets with these above, but it is more complicated to use them. Unless you are computer literate, sticking with the basic profile will be fine.
 
ClarityBill said:
I am using the BlueDriver OBDII and their app. I had it before the whole battery capacity thing came available
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Just to be clear - Your setup cannot obtain Battery Capacity, right?
The only methods I am aware of are the AP200, and the Vgate adapter with Car Scanner...
 
MrFixit said:
Just to be clear - Your setup cannot obtain Battery Capacity, right?
The only methods I am aware of are the AP200, and the Vgate adapter with Car Scanner...
Click to expand...
You are correct. The BlueDriver does NOT give battery capacity.
(I also bought one of your recommended systems to get battery capacity.)
 
Just acquired a Vgate iCar Pro Bluetooth 4.0(BLE) OBD2 Diagnostic Scanner Car Code Reader Scan Tool OBDII for Android/iOS, followed basic instructions in post 273, and had no problems connecting and reading my Clarity’s data using the Car Scanner Pro app on an iPhone. Instructions in post 273 were not exact but close enough that each step was easy to get through. Examples of differences: my Connect button color was blue; Bluetooth pairing was done entirely within the Car Scanner App; the Vgate ODB-II device does not even show up on my iPhone Settings/Bluetooth pairing menu; the list of Bluetooth devices presented in the Car Scanner/Device Selection menu included about 4 entries with no names, just numbers, in addition to the correct one which was the only one with a name – “IosVlink”, if I recall correctly - in addition to numbers.

Clarity details: Base model built Oct, 2019 and purchased new in Jan, 2020. It has only 3970 miles to date, unusually low due to a combination of COVID and being retired.

The total battery capacity reported by the Vgate ODB-II device is 53.98 Ah. I have entered this and associated info into the referenced spreadsheet. Unfortunately I was not provided with a reading of the Battery Capacity when the car was purchased, but it had just arrived at the dealer the day before we purchased it, and with zero problems experienced since then, a reasonable assumption would be that it was pretty close to the factory new spec (nominally 56 Ah, but I saw in the spreadsheet where dealers obtained readings closer to 55 Ah for new cars).

An L2 16 Amp charger has been used exclusively. Most of the time charging was started when at 25 to 50% SOC; maybe 10% of the time when SOC was lower than 10%; and maybe 5% of the time when SOC was higher than 70% (to “top off” before a trip). Average charges per week have been roughly 2, sometimes 3, except during the COVID peak mid to late 2020, when 1 charge per week was sufficient. Only 17 US gallons of gas have been consumed, which at 40 MPG calculates to about 18% of total miles being HV. Most (~75%) of the EV miles have been driven on town/county roads at 30 to 50 MPH limits, and ~25% of the EV miles have been on highways at 55 to 65 MPH. The car has been garaged and temperatures in the PNW are generally moderate (notwithstanding an all-time record setting heat spell this summer), so I suspect the 1 to 2 Ah loss of battery capacity since purchase is due mostly to charge/discharge cycles and very little is due to age.

As others have noted, MrFixit and the other contributors to this thread’s content deserve many kudos. It greatly helps to have a tested, known good approach to facilitate access to OBD-II data in any car, much less one that is not mainstream. That the knowledge gained has apparently been folded into at least one app (Car Scanner Pro) to make accessing significant data of interest a simple turnkey operation, with customization not needed at all but still available if desired by those so motivated, is a much appreciated bonus. Thank you all!
 
@PnwDriver,

Welcome to the Forum, and Thanks for the detailed report, and contributing to the shared spreadsheet..
I do not have any experience with iPhones, so your comments about pairing, etc. may be useful to others.

Can you explain where you got "nominal 56 Ah" for the factory capacity? We have always considered it to be 55 which is consistent with the PDI document, and initial dealer measurements (when available). It is also consistent with the advertised kWh capacity of the Clarity (17 kWh)... 3.7V per cell X 84 cells in series X 55 Ah = 17.1 kWh.
 
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Thanks for the welcome! I actually joined the forum when I first purchased the Clarity, but until now I have just been occasionally reading rather than posting. I've been interested in getting an OBD-II device, but didn't want to pay full "tuition" ;). This thread was just what I needed to avoid that, and the least I can do is contribute data to the growing spreadsheet as re-payment. Of course, for best interpretation of the data, driving context details are equally important, which is why I included all that.

I'm not sure why the factory capacity stuck in my head as 56 Ah but I revisited reviews and other blogs I've read and could not find a smoking gun. In any event you are right about the factory capacity, and with that my car's decline to date is just 1 Ah - makes me optimistic for a long service life.
 
MrFixit said:
* It has been a long time since I started from scratch.
Do me a favor - When you go through this, pay close attention and post any corrections to this procedure which I am trying to recreate from memory

Here is a basic guide:

1. Purchase the Vgate iCar Pro OBD2 adapter
2. Install the Car Scanner application on your phone.
  • Upgrade to the Pro version of Car Scanner (I think it is ~$4.95)
3. Plug the Vgate adapter into your vehicle's OBD2 port, Start the vehicle.
4. From your phone, find the Vgate adapter under Bluetooth settings and "pair" it with your phone.
5. In the Car Scanner App, go to Settings (the gear in the upper right).
  • Choose "Vehicle Option"
  • Select "Choose Connection Profile"
  • Browse to "Honda", then "Clarity PHEV"
6. Back out to the main menu and touch the large green Connect button. Car Scanner should acknowledge a connection to your vehicle.
7. At this point, you can select "All Sensors" and you will see a long list of values...
  • Scroll down the list until you get names that start with [Clarity]. These are unique to your vehicle.
  • Of highest interest to most is "[Clarity] Battery Capacity (total)"

* Note 1 - As discussed in detail in this thread, the Vgate adapter has a power saving mode and it WILL shut down after 30 minutes of inactivity. The only way to turn it on again is to unplug and re-plug it. Turning the car off does NOT wake up the adapter. If you use it regularly and want it to stay on, then you must execute a command described in post # 42 above.

* Note 2 - I will not offer a tutorial on how to use the more aesthetically pleasing aspects of Car Scanner (Dashboards, data recording, and such). You can learn these on your own, or read through this thread carefully and you will find some examples posted by us and others. @Hoon has posted a very nice Dashboard that you could learn to use if you want.

* Note 3 - Also, as discussed in the thread, the Clarity PHEV profile from Car Scanner is not 100% current. There are a few parameters that we found that have not been provided to the Car Scanner developer at this time. We posted load sets with these above, but it is more complicated to use them. Unless you are computer literate, sticking with the basic profile will be fine.
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Great thank you so much.

I haven't purchased it yet but I did get a handful of readings. Unfortunately my battery is only showing **48.24 Ah** max, which makes sense to why I've never seen >43 or so estimated miles if normal is 55ish.

Manufactured 7/18 I think I leased it Sept 2018 and just purchased the lease out.
 
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