Full Electric Charge and fuel comsumption

R

Randy Stegbauer

Member
I finally measured a full electrical charge from 0 EV. My Kill-a-Watt showed 14.5 kWh in just under 13 hours with a L1 charge. This is about 85% of the 17 kWh battery. For me at 12 cents per kWh that's about $1.75.

We were doing some long drives that day, so had to use gas :-( Most of the 150 mile drive was on the interstate at 50 to 70 MPH, and most of the drive was on HV. Maybe 10 or so miles on EV. It reported 50.4 mpg on the "Average Fule A" screen. Is this about what I should be expecting? Does running the heater or seat warmers affect this number?

Clarity HV MPG.webp
 
And the mpg meter on the dash notoriously exaggerates by about 10% consistently. You’d find that you actually got about 45 mpg if you were to fill up and calculate manually. Yes that’s about typical for a mostly HV drive at the speeds you mention.
 
That's consistent with what I am seeing.

I struggle with a meaningful replacement for the term "gas mileage" when dealing with a plug-in. It's misleading to quote a huge number when the reason it's huge is that you mostly drove within the EV range of the vehicle. The two parameters that have meaning for a given vehicle are the EV range and the gasoline consumption per mile when using the ICE.

You asked if using the heat and seat heaters affects the mileage. For the trip you took, no. During the driving in HV mode you were using waste heat from the ICE and the additional load from the seat heaters had an insignificant effect on the gasoline consumption. If you had completely used your EV range, the energy diverted by using the heaters would have affected your overall mileage because it would have lowered the EV range, thus reducing the number of miles where your miles-per-gallon were infinite. On a 150-mile trip, I don't think that this would be significant.
 
Agree, seat heaters are negligible (not quite zero, but will effect range about 1 mile in 2-3 hours driving time assuming they draw 100 watts). Heater will impact your efficiency, maybe 25% more or less, depending a lot on temperature and how hot you try to make the car and how long you are in the car. It draws around 7 or 8 kW (don't know exactly for Clarity), so the heater alone could drain the entire battery in a couple hours.
 
I filled it with 4.7 gallons for the 148 miles, which is 31.5 mpg. :( I'm hoping that I forgot that gas was used on an earlier trip.
 
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31.5 Mpg is more typical of HV Charge Mode. In HV mode, depending on speed, mileage (calculated, not read from the dash) should be anywhere between 38 mpg and 58 mpg, depending on your speed and driving style (you have to be running on the highway at 55 mph to 60 mph over relatively flat ground to get in the high 50s).

My guess then is that yes, your tank was not full when you set the trip meter. You would have to be driving in very bad conditions, or up a lot of hills and in a lot of traffic to only pull 31.5.
 
When clarity got delivered, on a 6.6kw for the charge the car took in 15.48 KW charge. I believe the battery is completely depleted as dealer did a 75 mile travel to deliver the car. At 88% efficiency, it took in 13.6KW to charge up the battery from empty after 2 months being empty.
I also wonder why wouldn't Honda charge the battery to 50% before shipping(for battery longevity)? Or maybe it does and the charge was lost during dealer travel?
 
Per the readings from by EV charging station (Juice Box Pro 40). 13.82 kW pulled from the wall to get a full charge not sure what efficiency to get. Garage temp was reported at 55 degrees.
 
ukon said:
When clarity got delivered, on a 6.6kw for the charge the car took in 15.48 KW charge. I believe the battery is completely depleted as dealer did a 75 mile travel to deliver the car. At 88% efficiency, it took in 13.6KW to charge up the battery from empty after 2 months being empty.
I also wonder why wouldn't Honda charge the battery to 50% before shipping(for battery longevity)? Or maybe it does and the charge was lost during dealer travel?
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Got my car directly off the truck and battery was completely dead. The dealer did not charge it during prep, either.
 
I just got mine about two weeks ago, and it was also brand new. The dealer didn't have a Level 2 charger (I think they only sold about 3-4 in all of 2018!), and they had it plugged into a regular wall outlet. When I took possession, it had about 6 miles EV. I think that's a little disappointing. If you're selling a car, the salespeople should have some better training on it. My dealership knew next to nothing about the battery operation of the Clarity. I think it must be pretty common to be delivered uncharged.
 
barnesgj said:
Got my car directly off the truck and battery was completely dead. The dealer did not charge it during prep, either.
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This is consistent with my experience and that of most of the folks on this forum. When I purchased the Clarity, I realized that I was essentially entering a beta test environment, and I was OK with that. But now that I'm here, I've been appalled by the lack of support both from my local dealer and from Honda corporate. I just don't see any support for this market segment at either level.

I love the Clarity. I think the basic design is sound and that, by and large, the engineers found the right balance between the various parameters, especially considering the concessions they had to make to the marketing folks. But Honda is just not supporting the car in any way. I have yet to find a single person who has even heard of a Honda Clarity. It's almost like the company is setting the car up to fail so they can say "We tried".
 
MNSteve said:
I have yet to find a single person who has even heard of a Honda Clarity. It's almost like the company is setting the car up to fail so they can say "We tried".
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It will be very interesting to see how Honda marketing supports the Pilot Plug-In Hybrid. We're the beta-testers for Honda's 2nd-generation plug-in hybrid system and the Pilot will be the system's mass-market application.
 
insightman said:
It will be very interesting to see how Honda marketing supports the Pilot Plug-In Hybrid. We're the beta-testers for Honda's 2nd-generation plug-in hybrid system and the Pilot will be the system's mass-market application.
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Have you read details of this? I assume it will be a similar electric side to our Claritys but with a 2.0 or 2.5 liter ICE to keep things moving better when the battery's done.
 
David Towle said:
Have you read details of this? I assume it will be a similar electric side to our Claritys but with a 2.0 or 2.5 liter ICE to keep things moving better when the battery's done.
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Honda never gives out details before their official product introductions.
 
David Towle said:
Have you read details of this? I assume it will be a similar electric side to our Claritys but with a 2.0 or 2.5 liter ICE to keep things moving better when the battery's done.
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Quite possible, but in their SAE paper it is clear that downsizing the engine was one of their priorities in the development of the Clarity.

"During both CD and CS operation, battery power is the main source of the demanded drive power in the high-load range, with the shortfall being supplemented through generation by the engine
The increased battery and VCU power realized in this system has expanded the range for EV power against the previous PHEV. Engine power has been reduced while increasing the motor power, making it possible to downsize the engine from 2.0 to 1.5 L."

...{and elsewhere}...

"...In Engine Driving Mode, the range for maintenance of lock-up is increased, making it possible to control increases in engine speed in the high vehicle speed range. The realization of high engine efficiency and increased quietness with reduced engine speed has made it possible to downsize the engine from 2.0 to 1.5 liters."

There is further re-iteration of this in the wrap-up at the end. My guess would be that Honda will again try to minimize the engine size in the upcoming Honda PHEVs to maximize efficiency, and minimize size (mass) and NVH.

I could be alone in this opinion, but I think there are limited circumstances where the Clarity PHEV engine power is a problem (and those concerns may be addressed in other ways besides increasing engine size - such as programming the system to keep a little extra reserve EV for high-load demands in HV mode), and so specific power and specific energy of the EV battery and DC-DC converter throughput and heat control may be a better way to manage needed power than through increasing engine size. Increasing the engine size will likely hurt efficiency in all cases, but only pays dividends in these high load demand circumstances. But to each his own. So far I have not encountered such circumstances {knock on wood}.
 
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insightman said:
Is the full paper available for viewing somewhere on the 'net? I've seen only the 5 preview pages.
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Sadly no - I purchased the full version from SAE. All their papers and documents are the same (exorbitant) price, and this one certainly didn't seem worth the cost, as I did not get much out of the last few pages which are not visible on the preview.

They are quite strict about copyright. I recall that it said I can only make a single printout and only keep one electronic copy on one computer. I doubt they could enforce it, but I'm not about to tempt fate by posting it for free on the web.

PM me if you have any specific questions and I'll see if it is addressed in the latter pages.

There are two other Clarity PHEV papers but I don't see myself purchasing those. I wish we had a library that allowed us to peruse them. There could be some interesting details in the Honda R&D monthly compilations that are also available - many of which show up on a search of 'Honda Clarity PHEV' - but the previews only show the table of contents so it is impossible to know if they have any real value.
 
Ray B said:
Quite possible, but in their SAE paper it is clear that downsizing the engine was one of their priorities in the development of the Clarity.

"During both CD and CS operation, battery power is the main source of the demanded drive power in the high-load range, with the shortfall being supplemented through generation by the engine
The increased battery and VCU power realized in this system has expanded the range for EV power against the previous PHEV. Engine power has been reduced while increasing the motor power, making it possible to downsize the engine from 2.0 to 1.5 L."
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They have to increase something because the PHEV Pilot will weigh probably 500-1000 lbs more than our Claritys.
 
Ray B said:
I did not get much out of the last few pages which are not visible on the preview
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I respect you for respecting their copyright and I thank you for spending the $28 to read the remaining pages so you could tell us they didn't reveal any essential information.
 
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