[JimWoo]

I am new to this forum and have a question. I have a 2018 Honda Clarity PHEV Touring purchased November 2018. I have put this question to my local Honda dealer and I have called Honda Technical Support and none have provided me a satisfactory answer. The Honda Clarity PHEV manual (page 466) states you should plug in the vehicle at the end of a day's driving so it can recharge completely before the next time the vehicle is used again. When I do this of course all the read outs indicate the vehicle accepts a full charge if left to charge undisturbed for the appropriate amount of time. However, in reading about EV vehicles there seems to be wide consensus you should never charge the battery bank consistently to 100% or it will lessen the life of the battery; many EV’s even restrict charging after 80 percent full. However, when I check for information about the Clarity PHEV and the Toyota Prius Prime for example, no such mention is made of restricting the charge to 100% at any charge interval. However, all other devices using lithium-ion batteries these days are generally recommending to confine maximum routine charge levels to 80 percent. I just don’t understand what makes the lithium-ion batteries in the Honda Clarity or the Prius Prime different from other EV’s, or all like batteries. Anyone got any information to clear up this seeming discrepancy?

 

[4sallypat]

Different & newer technologies.

Honda is very confident their batteries will last a lot longer than their ICE warranty portion of the car.

The SOC level may be of concern if you leave the car unused for months on zero charge, but for the most part, these batteries are "smart" and you don't have to worry about the old battery concepts of "memory" or "thermal runaways"....

I am so confident because Honda warrants the expensive batteries in CA for 150,000 miles - more than I typically keep a car!

Just plug her in whenever you can to maximize the EV miles and enjoy.

 

[Rob43]

OP,

When you charge your Clarity to 100% & discharge it to 0%, your Clarity is actually charging/operating at roughly ~80% full and down to roughly ~20% discharged.

My numbers might not be perfectly accurate, but they are close enough. Honda understands how to keep a Li-ion battery in great condition for the longest period of time, and they build that into the charging circuitry of your Clarity.

So enjoy your car & don't worry about it, it's all been taken care of in the initial design.



Rob43

 

[obermd]

The biggest offender on not protecting the battery is Nissan. Rather than having the car's computer system handle charging duties, the Leaf owners manual explicitely states Do Not charge when the system is hot; do not leave plugged in after charging, etc. Nissan has had to replace way too many batteries because of this.

You have a smarter car - it wont overcharge or undercharge. It also maintains battery temperature for you.

 

[JimWoo]

Thank you for responding. Very helpful.

 

[JimWoo]

Thanks for that response. It would have been nice if Honda had included those details in the section on charging so anal retentive owners like me would’t lose sleep worrying about the issue. Glad to have an answer.

 

[obermd]

Thanks for that response. It would have been nice if Honda had included those details in the section on charging so anal retentive owners like me would’t lose sleep worrying about the issue. Glad to have an answer.

Agreed. Honda seems to have a very paternalistic attitude towards vehicle owners, especially when it comes to the powertrain and how to best manage it.

 

[4sallypat]

I love the Clarity - all past 4 Hondas have been the same - no issues since day 1.

Mine was a December 2018 manufacture which I picked up at the end of December and found it had already all the SB installed.

No trips to the dealer for any updates, complaints, concerns, etc....

Love this smart car!

Check out another forum member who had the service dept run a 5 page detailed analysis of the battery, charger, and all related car functions:
https://www.insideevsforum.com/community/index.php?threads/battery-capacity-test-results.5836/

 

[Kerbe]

Thanks for that response. It would have been nice if Honda had included those details in the section on charging so anal retentive owners like me would’t lose sleep worrying about the issue. Glad to have an answer.

In addition, the charging/degradation issues are mostly about Level 3 DC charging, when huge amounts of kW are being forced into the traction battery. Level 2 charging, using the car's internal AC charger, is rather gentle - more like a faster version of a "trickle charge". The Clarity manual is a masterpiece of understatement: It gives me the impression that Honda assumed 1) that no one ever reads a manual and 2) the average Clarity driver just wants to get in and go and not have to worry about techno stuff. Try, for example, to find the capacity of the traction battery or the charge rating of the onboard charger - it's really well hidden!

 

[obermd]

In addition, the charging/degradation issues are mostly about Level 3 DC charging, when huge amounts of kW are being forced into the traction battery. Level 2 charging, using the car's internal AC charger, is rather gentle - more like a faster version of a "trickle charge". The Clarity manual is a masterpiece of understatement: It gives me the impression that Honda assumed 1) that no one ever reads a manual and 2) the average Clarity driver just wants to get in and go and not have to worry about techno stuff. Try, for example, to find the capacity of the traction battery or the charge rating of the onboard charger - it's really well hidden!

I'm starting to think Honda's attitude is what's needed for EVs to make serious market penetration. EVs to date have mainly been purchased by geeks or status seekers (via Tesla). The first group, geeks, want the technical details so they can argue about them. The second group is more interested in being first to something new. GM and Tesla focused on these two groups in their marketing and generally available documentation. Unfortunately, that leaves the vast majority of car buyers who just want to go from point A to B and really don't care about how the car gets them there. Honda's published documentation is aimed straight at this group.

 

[60Hertz]

If you have a charging app like the one for the ChargePoint network that shows the rate of charge in near real-time, you will see that the rate of charge falls off as the battery nears fully charged. If convenient, I'll check on the app around the time I figure I should be nearing fully charged and then hit the app "stop charge" button as soon I see the charge rate drop. A few reasons for this: 1) ChargePoint fees are based on the time you are charging, not the energy delivered, so the last bit of charge at the slower rate is relatively more expensive. 2) Leaving work for me is a slight downhill to start with, and I can capture that with regen if I have some headroom in the battery. 3) I can easily make it home on less than a full charge, so I don't need that last mile or two of electric range I would get by letting it charge all the way to the end. All of this is pretty small potatoes, so if I'm busy or forget to check it, no big deal. At home, the entire charge cycle happens while I am asleep, so it gets the full charge.