New owner with EV range concern

I love that idea. If only the Clarity had something like the Bolt's "hilltop reserve mode." (My apologies if I'm the 348th person to lament the fact.) On the bright side: Claritys (Clarities?) don't burst into flames when you charge them.

https://www.mychevybolt.com/forum/viewtopic.php?t=7338

-Matt

 

I agree. I wish the app had a charge to 90% option as others have said. But I'll try setting a start and end charging time to approximate 90%. i.e. 2 hours 10 minutes of charging instead of 2 hours 30 minutes or whatever, and see how it goes. This will help in the summer where I often start the gas motor going down hill because the battery is full. In the winter, I just turn on the heater, and that zaps it down enough...

-Dan

 

I'd love a 98% charge.... I live on a steep but short hill, and many times I'll trigger the regen overflow -> gas engine just by coasting down from my house. Blows my mind that it fills it so much that even 5 seconds of regen triggers it... I do my best to not hit the pedals until after I'm a few blocks from my house but sometimes just autopilot them while still in my neighborhood and trigger it

 

And not to throw a wet rag on the good idea but it would of been AWESOME to have a hill mode, or a percentage charge option.
Reasons why just setting the charge timer isn't so great:
- My pattern changes a bunch. I have days where 1/2 of my EV range is still there. I can't programmatically and daily adjust for this easily. For tomorrow would I set my charge time for 1 hour? Even if I could easily compute exactly additional time to get to say 90% charge, I'd still have to modify my charge schedule, and in my case maybe daily. I don't always drive the same distances per-day.
- If I guess wrong at how much charge I need to get to 90% it will stop at 100% automatically but it's not 90%.
... you get the idea. There isn't a simple way to limit the charge. (but open to feedback on that).

 

Here’s the basics of a trip we made yesterday. We’ve done it about once a month for the past 4 months. Round trip is 62 miles. The first 20 is about 500’ downhill for the first several miles. Neither the wife or I have triggered the ICE on the downhill with either the paddles or brake pedal. A few days ago I actually jabbed the brake pedal to avoid hitting a fawn. No ICE. Then a gradual uphill to about the 20 mile mark. At that point there is a 2400’ elevation gain over 8-9 miles followed by a slight downhill.

EV range is typically nearly exhausted at the first crossing of the summit. Yesterday there was about 4 miles remaining, but on the return trip, EV range expired 1/4 mike short of the summit.

On the 8-9 miles descent, 4 bars, or 10 miles of EV range was added. In total, we used 10 miles of HV range. The EV range estimate this morning was 50.4 miles.

If there’s a moral to this story, it’s that with a hill in the middle of the trip, rather than the beginning and the end, an opportunity is created where you get a “free” ride and recapture some energy.

 

This experiment seems a little tricky to me. Just to illustrate, let's make some numerical assumptions.

First , assume that the inherent EV range is 48, but the hilltop scenario is reducing it to ~40. The hypothesis is that Dan's GOM is telling him 40 because it learns this hilltop scenario.

Now, instead of charging to 100%, you start charging to 85% (in order to have room for the downhill regen). The GOM should indicate .85*40=34 miles (It hasn't learned anything new yet). This would need to be repeated for several consecutive days, but if every day, you start with 85%, then the GOM will hopefully learn that there are ~8 miles gained because of the previously lost regen that is now being captured. The starting EV range should increase by ~8 miles (increasing from 34 to 42) with the 85% charge. This would mean that a "full" charge 'could' yield ~42/.85=49 miles.

After the experiment is done, then charging to 100% should show this ~48 mile range at first (until the GOM once again re-learns the old scenario and knocks the estimate back down to 40)...

I think this is a very good experiment, but it is tricky to perform it in a way that yields convincing results.

If this proves out, then it would behoove Dan to always start with 85% charge so he can capitalize on the initial regen that he's loosing right now...

 

@Dan Albrich -
One step at a time. Don't worry about automating this process until you can demonstrate whether this hill scenario truely explains your observed range deficit. To conduct the experiment, don't try to time things to acheive the desired SOC - Just monitor the charging process with HonaLink and terminate it when it reaches 85%. If you can demonstrate the principle, then maybe we can come up wth a suitable to mechanize it !

 

I actually don't mind taking the time to gather data and to learn from it. In a practical sense, the car is shared, and we have a lot of stuff going on so I can't guarantee the charge setting will be a particular value-- except in cases where I last drove it I suppose. Not the end of the world, but it may take me awhile to test.

 

@Dan Albrich thanks for bringing that spirit to the forum. Fits very well with my "it never hurts to ask" philosophy.

Speaking of data, I'm inspired by the Battery Capacity Data tab on our shared spreadsheet), and so I've started working on some very basic formulas to compute (between each gas-station visit) things like:

• Number (and percent) of EV and HV miles driven
• Total and HV mpg
• Number of gallons (and percent) of gas used
• Cost per EV and HV mile

At this point I don't foresee any huge insights to emerge (e.g., after about 750 miles since last fill-up, we've saved roughly $15 by driving 85% EV vs. 15% EV).

My goal at this point is to invest some time in generating the numbers and to use what emerges as a springboard for new questions, new analytical methods, new actions and options, etc.

Side-note: one of the REALLY FRUSTRATING things about this endeavor is that the first (and so far ONLY) row in my spreadsheet is dated 7/28/2021, in which I topped up to 7 gallons. It is now roughly A MONTH later, and we've used a grand total of 2.7 gallons, which means if I want to start a new row when I fill up again, IT COULD BE sometime in October or who-knows-when. In other words: I'll probably bail on this data-collection exercise once I begin to realize that we're only filling up the tank a few times a year. Funny how life (with a PHEV) works.

-Matt

 

I'd think it will take a few runs back to back for the meter to learn it and consistently show the additional mileage missing in all readings. Otherwise, the other drivers/charging routines are going to muddy the waters.

Living along the flat gulf coast, I discovered a recapturing "trick" in my C-Max Energi which doesn't have a HV+ mode to build EV miles with gas. With some EV miles left, switch to HV mode (which creates a set-point in the HV batteries' SOC) and drive. Before coming to a high-speed stop (highway exit ramp for example), switch to EV (only) mode and brake for max. regen using gauges as a guide. Then at the stop, switch back to HV mode again. This sets a new yet higher SOC set point that includes that captured regen. Rinse, lather, repeat, and I could see gains of 5-6 miles EV over the 80 mile roundtrip from that regen. I'd see estimates of 30 miles (EPA 19) the next day!

When will vehicles see and anticipate the topography AND utilize it as part of range management/fuel economy?

 

That trick would be tricky in the Clarity. HV Mode establishes a SOC set point. That set point fluctuates, primarily lower, until the generator is signaled to begin charging. Unless you know the exact SOC when switching from HV to EV, and you know the exact amount of energy that will be recaptured while in EV, it is quite likely that you will be setting a new, lower, set point each and every time you perform the button pushing sequence.

In my experience, coming off the throttle while in HV, shuts the engine down. The ensuing coasting and/or braking aids in restoring the SOC set point. I have no experience with the C-Max. On flat terrain in a Clarity, switching modes is futile. If a significant descent lies ahead, then some meaningful energy can be recaptured by switching to EV.

 

I think a page or 2 back I noted that integrating the GOM with a navigation (e.g., Maps) system is something on the order of a capstone project for a senior CS undergrad. Pretty trivial for a full-time engineer or a few months work for a Honda intern. Well, we'd also need a planned route but that's easy -- without one, we could use a heuristic that, say, the driver planned to stay on the current road for the next 5 minutes and project from there.

On the practical side, though, I wonder if there are all kinds of barriers to having those data in hand (e.g., third party licenses, real-time GPS access, etc.) and perhaps even potential liability if the topography data are incorrect or outdated (seems unlikely but I err on the side of caution).

EDIT: not sure if this is an "alternate fact" but it seems like maybe Tesla's already do this (emphasis added):

https://insideevs.com/features/401481/tesla-range-estimator-improvement/

-Matt

 

A Tesla, or any BEV, can only use terrain data to estimate range. Nothing can be done to improve efficiency. All the energy goes in or out of the battery and it’s going to take the same amount of energy to get from A to B, whether or not the car knows what lies ahead.

A PHEV could theoretically benefit from such data. In the case of the Clarity, I’d rather they put the effort into a more powerful windshield washer pump.

 

My now "ancient" C-Max has a feature called EV+. By using the factory GPS, it can identify frequent destinations like home or work. Then if traveling in EV and the car "sees" that it will not have enough EV range left to make it to the destination it will allow the car to dip into the hybrid portion of the pack and NOT fire up the ICE. At best this is a only a mile or two under a light pedal but that's so often the difference. Nice feature.

I know Toyota is also using some predictive behavior route analysis via the onboard GPS.

 

Yikes, I hadn't gotten that memo yet. Now I'm curious/worried.

*facepalm* Now I know what my "most-lusted-after" Clarity feature is.

-Matt

 

I've had my 2018 Clarity about 2 months now. I got it with a drained battery and drove it 100 miles home and plugged it in. The next morning it showed a 37 mile range. I was disappointed but figured due to 100 degree heat (Texas) and a 3 year old battery perhaps that would be the norm. However, each day I drive it that morning number goes up. Now it hovers around 44 - 47 each day. If I drive much freeway the day before it's in the low 40s. If I drive a lot of stop and go, using the paddles to slow the car, I get close to or at 47. As many people have said, the computer estimates what your mileage will be based on how you drive, use of AC or heat, etc. Congrats on the new Clarity! You're going to love it!!

 

In my experience the same amount of energy will be recaptured whether using the brake pedal or paddles. So it really boils down to which method is preferred.

 

If you’ve used the windshield washer, you may have noticed that the fluid is emitted in a similar fashion as drool from a baby’s mouth. The drool alternates sides so as to always be emitted from the trailing edge. This makes the first swipe a dry rub. The ensuing swipes gradually encounter more fluid, and given sufficient time, the wipers may be provided enough drool to actually clean the area over which they travel.

 

Does any other Honda use the same windshield-washer system or were we testing it for Honda? It would be interesting to see a video of Honda's engineers in the lab testing the final version of the Clarity's windshield washer system. Did they exclaim, "Eureka! We nailed it! This system conserves washer-fluid so well that we can use a thimble as the reservoir!" On what projects are those engineers now working?

 

AH! Come to think of it, in the three months of ownership (hey @RickH we've got a 2018 like you!) there was one occasion to use the windshield wipers. But my wife and daughter were so charmed by the "reciprocal" wiping pattern that I completely forgot I'd noted the...how do I say...lack...of lubrication. I hadn't thought at the time about baby drool but now I will forever after!

I'll just go on the record as saying I'm fine (relatively speaking) with the drool method, so LONG AS I NEVER get to see glowing green globs of goo come from the other end of the wipers (the metaphorical "nose" end, I presume). Putting two kids through preschool and kindergarten was enough green goo for me thanks.

-Matt