Budget Battery Capacity Readout

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.

 

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.

 

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?

 

Just put mine on the scanner - seems a bit high. 2018 with 30,000 miles

 

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.

 

What device do you use and what app?

 

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?

 

I am using the BlueDriver OBDII and their app. I had it before the whole battery capacity thing came available...

 

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!

 

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.

 

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.