Budget Battery Capacity Readout

@coutinpe I am replying to this old message to let you know that I have stopped mounting my phone on the left hand side of the dash since I realized that anything mounted there could potentially be in the path of an airbag. It would not be safe to have a phone flying around the cabin at high speeds. I now have to use some floss to remove the sticky pad!

 

I am new to this great forum, but I have learned a lot about my 2018 Honda Clarity Touring PHEV. A consistently decreased vehicle electric range (36 miles) prompted me to find folks like you all. I bought the Vgate iCar Pro Bluetooth (BLE) on Amazon, and installed the Car Scanner app on my Android smartphone. Simple connection thanks to the available Honda Clarity PHEV profile in the app.

My car is 5 years (60 months) old this month, as I was one of the first 10 people in Austin, Texas to buy a Clarity PHEV in December 2017. I have 21,873 miles on the odometer. My BPC reads 45.28 Ah. This equates to a 17.7% decrease in capacity.

So, it's a race to 8 years in service and 36.6 Ah for a new battery under warranty. It appears battery degradation is time related, perhaps more so than mileage and recharging frequency. I recall in Spring 2018 getting 52 miles per charge.

 

First off, your dedication and due diligence are commendable!

Your reading is somewhat interesting. The average for a vehicle with ~20K miles is 50.5 Ah, but as you mention, the battery capacity is multi-faceted.

I wonder if lithium ion batteries degrade over time, independent of the number of charging cycles? I recall that unlike nickel metal hydride batteries that develop a memory and lose recharging capacity, lithium ion ones do not.

Are most of your miles EV?

Yes, I use to be able to use all EV. Now, with the loss of BPC and EV driving range, 85% to 90% of my miles are EV. I have always used my EV motor until it goes empty and then the Clarity switches to HV mode.

How often do you charge?

Two to three times per week, whenever the battery is depleted.

and is it Level 1 or Level 2?

Clipper Creek 240V, 40 amp Level 2. I am tempted to try using the Honda OEM Level 1 charger to see if I see any difference.

It's pretty hot in Texas, and maybe temperature is also a factor.

Yes, our Texas summers are brutal. Oddly, lately, even on temperate fall days, my range will not go above 40 miles. But I am going to start the using the trip odometer to confirm my actual driven EV range.

Is there a way to reset the estimated mileage calculator on a Clarity? Like resetting the MPG on other cars?

 

I tried an experiment the past year. One caveat with our Clarity data is that we do not put very many miles on our Clarity, averaging about 2500 miles per year. For the first four years, the battery capacity went from r 54.6 AH (10 months after new, 2/2018, purchase) to 50.14 AH. The battery capacity measurements were always taken after a full charge (to 100% SOC) from an SOC below 30%. For those first four years, I charged the battery about once a week and the SOC often got 30% or less before charging to 100%.

I noticed that many Clarity owners who had experienced the least battery degradation were keeping the battery SOC between 40% and 85%. For the past year, I used the Honda SmartCharge app to limit the charge to 85% and we charged the Clarity whenever the SOC got below 70%. The SOC rarely got below 50%. Ten days ago, I let the SOC get below 20% (about 15%) and then did a full charge. This deep SOC value was the first deep discharge in 9 months. After the full charge, the battery capacity measured 50.06 AH. The 9 month loss was only 0.08 AH, an anual loss of aabout 0.11 AH. While we were able to completely limit deep battery discharge, the Honda SmartCharge often did not stop the charge at 85% and I would estimate that about 25% of the charges went well above an SOC of 85% (more so lately as SmartCharge seems to be more hit and miss the past few months).

We will continue this charging routine. Such a charging routine may not work for most as we do not put many daily miles on the Clarity which is used mostly for in town driving. We do use the HV mode when longer trips are made. However, aside from the battery aging in time, I am of the opinion that deep discharges adversly affect the battery capacity (full charges may alsio have an effect but not as severe).

My two cents, LP

 

Lithium battery degradation isn’t linear. There are many factors and an infinite number of variables to consider. To be frank, you’ll never know exactly why your capacity has decreased or what the capacity will be in 3 years.

Also, the warranty does not specify a “new” battery. A replacement battery only needs to have a capacity that exceeds the warranty threshold of 36.6Ah. At least two members of this forum have had the Lithium battery replaced. I believe both were due to a failed cell and both received new batteries.

At the 8-10 year anniversary of the first Clarity sold, it could be possible that a battery replaced under warranty may have been manufactured 8-10 years ago. Some degradation will have occurred over that time period, regardless of the conditions under which the battery was stored. It is also possible that a battery replaced under warranty at the 8-10 year mark will be a salvaged or reconditioned unit.

 

Keep in mind that the targeted cell charging voltage of 4.09x volts, as per the Honda charging protocol, equates to a SOC of approximately 90%. The 3.7V cells would be 100% charged at 4.2V.

A device that indicates that Battery A & B are at 100% SOC at ~344V, is a devices that is providing less than accurate data. Of course, with Lithium batteries, deriving a SOC percentage from voltage is not the most accurate method for determining SOC.

Charging a Clarity to 85%, is charging to 85% of 90%, or 76.5% of the actual maximum capacity. Something else to consider, is that cell balancing typically occurs near the end of a full charge cycle.

 

Gee, thanks! I ended myself getting a vent-fixed magnetic mount on that left side vent, it still allows a decent view of the phone screen without too much glancing away from the road and I think it's well out of the way of any potential airbag deployment. I owe you the photo, will get it ASAIC.

 

Hey, I just bought a Clarity last week and also wish I'd known that I could've checked battery capacity before buying!

Question - I have an OBDLink LX and when it's connected it works perfectly! However, it only stays connected to my Android phone with Car Scanner for a few minutes at a time. After a few minutes in the Car Scanner dashboard view, it stops updating and if I go back one screen it shows Car Scanner as a yellow "Connecting" to the OBD device and a red "Disconnected" from the vehicle ECU - instead of green "Connected"s.

Any ideas? Not sure if this is an issue with the LX, the OBD port, or the Car Scanner app.

Same question as above - OBDLink regularly disconnecting from Car Scanner. 2008 Prius did not have this disconnecting issue with the same OBDLink LX + Hybrid Assistant / Torque Pro.

Stayed connected on the Clarity for a enough time for me to get a battery capacity reading though, thanks! 48.02 Ah at 41,961 miles.

 

I tried an 10 years old ELM ODB, and carscanner wasn't able to show battery capacity. It shows cell voltage though. Can capacity be estimated?

Car is 2019 with 14k miles. Mostly driven under 60, non highway
Electric range, Summer high was 52, December high is 42

 

I'll try out the Vgate iCar Pro, thanks! The listing in your github Option 2 instructions .pdf doesn't match anything currently available on Amazon, so should I buy the only iCar Pro bluetooth available from the "Vgate store", shipped from Amazon and sold by "Everything Under the Red Sun"? The Amazon item number is B07R4WZWFC, not sure if I can post links here. Or Vgatemall's website has the iCar Pro for sale as well...

And yes, I'll keep track of approximately how many miles I do in electric vs hybrid mode and charging habits for future entries in your spreadsheet! For now I've only had this car five days and I don't know how the previous owner charged it - L1 / L2 / no wall charging at all.

 

I have the Honda extended 8 year/120,000 mile warranty. There is an inconsistency on this under what is not covered, that section includes: "battery (except for the nickel-metal hydride battery in hybrid vehicles)". So we have a hybrid vehicle battery but its not nickel-metal hydride. So is it possible I qualify for the extra 20,000 miles of coverage? When I bought the car I didn't yet know what kind of battery it has.

Honda of course doesn't have the greatest reputation for honoring warranties anyway.

There's a good chance this is a moot point, I'm at 67,000 miles now so a long way to go.

 

My gen-1 Honda Insight had 120 NiMH D-cell batteries--not even a full kWh worth. The gen-1 Civic Hybrid and gen-1 Accord Hybrid also used NiMH batteries. Evidently, the text of the Clarity's warranty was lifted from the olden days. Fortunately, the Clarity PHEV's Li-Ion battery is covered by an 8-year/100,000-mile warranty in most states (and longer in a few states).

 

I just broke 100k miles so I figured I would check the battery capacity again. As of today with 100,093 miles it is showing 45.0 ah.