EV vs HV mode

[MNSteve]

Is the idea that HV mode maintains the level when HV is started in a manual somewhere? I'd like to read more about that since mine did not seem to be doing that.
I could definitely tell when the engine was working harder for accelerating or slight hills but not otherwise.

Are you absolutely sure you were in HV? Did the small HV icon appear on the console? As others have pointed out, if you take a break you have to remember to push HV again.

Your experience is much different than mine, which is in line with what others have reported. I might lose a mile or two in a 50-mile highway leg, but that's much different than what you report. One thing you might try is observing the behavior of HV-Charge ... not suggesting that you want to use it on a regular basis, but knowing that it works as it should is another data point.

 

[MPower]

Drove 1000 miles in 2 days with heater on my Christmas trip and same return. Had a full battery to start the first day, but being cold the GOM showed estimated miles in low 30s. Still had battery left at the end of my trip so I turned off HV and finished up EV.

I was mainly using ACC with interstate driving and kept my speed under 70.

 

[oddhack]

From page 16 in the "big" manual which you can download from
http://ev.owners.honda.com/Clarity/ModelInfo/PlugInOwnersManual?pageMenu=PlugIn2018

View attachment 5158

I'm skeptical. I have a weekly drive where I put it on HV mode when I get on the highway for the first 15 miles or so, then complete in EV mode. When it's in HV mode, EV range shown on the dash goes down steadily from starting ca. 50 to low 40s, so it's losing about 1/2 mile in estimated EV range for each highway mile driven in HV mode in this scenario.

 

[ClarityBill]

In HV mode, the car uses the battery to balance the load on the internal combustion engine (ICE). This means that the battery will discharge for a while, and then recharge. The problem with going to HV mode at high levels of charge is the battery does not recharge very well. The flow in and out of the battery is more balanced when the battery charge is down a little. (One of the reasons HV charge mode only goes to 57%.)

 

[2002]

I'm skeptical. I have a weekly drive where I put it on HV mode when I get on the highway for the first 15 miles or so, then complete in EV mode. When it's in HV mode, EV range shown on the dash goes down steadily from starting ca. 50 to low 40s, so it's losing about 1/2 mile in estimated EV range for each highway mile driven in HV mode in this scenario.

I guess since there is no official name for this I will refer to it as "HV leakage". Different people seem to have different amounts of HV leakage, presumably related to driving conditions. In my case I leave home with a full charge and drive nine miles at 45 mph on EV, then I get on a 65 mph freeway and switch to HV. After I switch to HV, EV range continues to drop about 2-3 miles as ICE warms up, then it slowly climbs back up to the preset level, or at least within about 1 mile. Then it holds it pretty steady for the remainder of the twelve mile freeway drive. It sometimes "borrows" a mile or two of range but then usually pays most of it back. I haven't made any long trips but based on other reports many people experience a couple miles or so of HV leakage for every 100 miles of driving, others say they experience virtually none.

ClarityBill suggested that your excessive HV leakage may be due to starting HV with a nearly full battery. How many EV miles do you drive before switching to HV?

 

[qwerty607]

I've had a few medium distance drives since my last posts and wanted to give an update.
When I have Econ and HV selected the system will NOT maintain the battery level. Based on observations this seems by design. The power gauge is partially blue fairly often and the battery range never increases with the exception of significant braking or downhill sections.
If I turn off Econ (i.e. normal) and have HV selected then the battery state will be maintained. I've noticed the range fluctuates slightly around the set point but usually within +-1mile.

 

[MPower]

When I have Econ and HV selected the system will NOT maintain the battery level.

That is weird. I have my car in ECON all the time. When in ECOM/HV, the car maintains the SOC. In January, the car maintained the SOC for a 1,000 mile trip over 2 days. Lost a few miles each day, getting started in the morning and after stopsnbefore engaging the HV button..

 

[MNSteve]

That is weird. I have my car in ECON all the time. When in ECOM/HV, the car maintains the SOC. In January, the car maintained the SOC for a 1,000 mile trip over 2 days. Lost a few miles each day, getting started in the morning and after stopsnbefore engaging the HV button..

This is consistent with my experience. On the highway I usually drive in normal (not ECON, not SPORT) because I feel it makes the ACC more responsive. But what I see when I watch the range display on the front console (the one that has tenths of a mile) is that it will "steal" a bit of range going uphill and then return that loan to keep the EV range constant within a mile or so.

 

[ClarityBill]

I normally do not lose EV range in ECON. But I lost it this week when I had fresh air selected for climate control instead of recirculated air. It seemed worse when it was raining with fresh air. I once lost EV range badly in the winter, in a snow storm...

I think the Clarity might be running dehumidification (with the electric heater). Puts large load on the high voltage electric system, and the ICE cannot keep up. I also like to keep the fan speed close to high.

 

[2002]

I also like to keep the fan speed close to high.

I prefer to keep the vent to the left of the steering wheel closed as no matter which way I point it there will be some air blowing on me which I don't really like. The downside is this requires higher fan speed and lower temperature setting since you are not able to take advantage of the "wind chill" effect of having air blowing directly on you. But I can tolerate the vent open at least briefly and I often open it up when I first start driving, it generally feels good anyway at that point and that way I don't have to run the AC as hard. But eventually I get tired of it and close the vent, usually by then the car has started to cool down anyway. If it's a hot day and taking longer to cool then sometimes it's a bit of back and forth with the vent. When I can't tolerate the heat anymore I open the vent, when I can't tolerate the vent anymore I close it Or sometimes I just go ahead and "splurge" and keep the vent closed and crank up the fan all the way.