HV Charge mode "unsatisfying"

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ozy

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Today I tried HV Charge mode for the first time and was confused with what it was doing. As context: I had distractedly let my EV miles run down to zero during a freeway trip. So, because it's better to have a few EV miles remaining, I thought I would try "HV Charge" mode. I activated it and noticed right away that the car engine was noisier than normal (no surprise). I also noticed that I was losing "HV miles" a little quicker than usual but I already know that in HV Charge mode there is less mpg efficiency. The thing I wasn't prepared for is that at no time did I see that I was generating EV miles. I let the car run in that mode for at least 8 miles and never saw the EV miles climb beyond "0" or see a third EV bar. After a while I disabled HV charge and the engine got a bit quieter and I drove the rest of the way home. At no time did I ever see that I had generated any EV miles. What am I missing?

Unrelated question: If you run out of EV entirely is it neccessary to switch to HV mode or simply let the car do what it wants? I noticed that I could switch to HV by pressing the button but did not understand if that would make any difference at all.
 
I have used HV Charge successfully. The effect is not immediate. I would have thought that 8 miles would have been enough to observe some change, but I don't remember the rate of energy addition to the battery.

No, if you run down to two bars or so, the car will switch to HV (or perhaps it would be more accurate to say that it will switch out of EV mode) and the operation will be the same as if you had done it. The only difference is that by definition, since the car had not done it, there was at least a tiny bit more battery charge than what the controller considers "zero".
 
ozy said:
Unrelated question: If you run out of EV entirely is it neccessary to switch to HV mode or simply let the car do what it wants? I noticed that I could switch to HV by pressing the button but did not understand if that would make any difference at all.
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If you run out of EV entirely and you have big hills to climb then you need to put into HV Charge, preferably before the hills and before you run out of EV entirely.
 
ozy said:
If you run out of EV entirely is it neccessary to switch to HV mode or simply let the car do what it wants?
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Page 15 in the Owners Manual says:
When the remaining power of the High Voltage battery drops to a certain level, the vehicle switches to HV.

However, the HV icon does not illuminate when the Clarity activates HV in response to zero EV range. The HV icon illuminates only when you press the HV button. I assume the auto-activated HV doesn't display the HV icon because the designers don't want people pressing the HV button in a vain attempt to de-activate HV.
 
ozy said:
What am I missing?
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What you're missing is that you didn't run the engine nearly long enough to add much charge to the battery. The engine generator charges the battery by time running, not by miles traveled. If you had the engine generator on for only 8 miles on the freeway, that would have been a very brief time. I don't know how long the engine generator needs to be running to charge the battery one bar, but I suspect it's a longer time than going just 8 miles on the freeway.
 
@Sandroad is spot on. Regarding HV CHARGE, page 17 in the Owners Manual says:
The high voltage battery can be charged to 12 segments in after about 1 hour of high-speed driving.
 
MNSteve said:
I have used HV Charge successfully. The effect is not immediate. I would have thought that 8 miles would have been enough to observe some change, but I don't remember the rate of energy addition to the battery.

No, if you run down to two bars or so, the car will switch to HV (or perhaps it would be more accurate to say that it will switch out of EV mode) and the operation will be the same as if you had done it. The only difference is that by definition, since the car had not done it, there was at least a tiny bit more battery charge than what the controller considers "zero".
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I put it in HV Charge mode to keep get heat out of the engine when driving around town.
I'm old and drive like Ken, so the engine never races, but the EV range miles slowly increase.
I wouldn't think range miles go up in regular HV mode.
 
Atkinson said:
I put it in HV Charge mode to keep get heat out of the engine when driving around town.
I'm old and drive like Ken, so the engine never races, but the EV range miles slowly increase.
I wouldn't think range miles go up in regular HV mode.
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How does HV charge get heat out of the engine?


Sent from my iPhone using Tapatalk
 
Sandroad said:
What you're missing is that you didn't run the engine nearly long enough to add much charge to the battery. The engine generator charges the battery by time running, not by miles traveled. If you had the engine generator on for only 8 miles on the freeway, that would have been a very brief time. I don't know how long the engine generator needs to be running to charge the battery one bar, but I suspect it's a longer time than going just 8 miles on the freeway.
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Also at freeway speeds, MOST if not all of the generated power is being used instantly to keep you at freeway speeds, HV CHARGE mode would (and does) show more charging “per minute/mile” at lower city speeds and stop and go traffic.
 
Battery temp and power demands will change how quickly it charges. If the battery temp is very cold it won't charge quickly (I realize now this is why it didn't work first time I tried it). It charges the battery rapidly when it is running.

Generally, this mode should be avoided, unless you really need it. Otherwise charge from the wall. If you need it, be sure to engage it 45 minutes or so before you need the electric range. Best to use HV from beginning of the trip though.
 
Freeway driving is very high load. Big drain on battery. So charging on freeway will always be slow. Charge is going out almost as fast as he engine can put it back in. 8 miles of freeway is only about 8 minutes. How many miles of charge do you get when even plugged in at home for 8 minutes? Not much....and that’s with car off/zero load.

Results of this test are exactly as I would expect...for 8 minutes of freeway driving. Note HV charge mode serves no practical purpose I can find...it’s a very wasteful and inefficient way to charge the battery. I simply advise to everyone that they not use it, even if you do find yourself surprised with zero EV, and ignore the fact the feature exists. Just make sure it has gas, and drive the car. It’ll get you where you need to go, then plug in.
 
craze1cars said:
.... Note HV charge mode serves no practical purpose I can find...it’s a very wasteful and inefficient way to charge the battery. I simply advise to everyone that they not use it, even if you do find yourself surprised with zero EV, and ignore the fact the feature exists. Just make sure it has gas, and drive the car. It’ll get you where you need to go, then plug in.
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Exactly.
 
craze1cars said:
Note HV charge mode serves no practical purpose I can find...it’s a very wasteful and inefficient way to charge the battery. I simply advise to everyone that they not use it, even if you do find yourself surprised with zero EV, and ignore the fact the feature exists. Just make sure it has gas, and drive the car. It’ll get you where you need to go, then plug in.
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I agree that it is an inefficient way to charge the battery. I very seldom use it. But for me the tradeoff of burning some extra gasoline so that I can drive around town in EV mode is worth it; that's because I seriously prefer EV to HV around town. Normally I can just use HV on the highway and save my EV miles for in-town driving, and that's plenty. It is only when I am on a long trip with no access to charging that I resort to HV-charge.

And one more comment. One of my mantras on this forum is "Options are good." HV-charge is an option; I like it; you do not; that's absolutely fine. But I'd rather have the option there and not use it unless it affects the overall operation of the car even if I choose not to avail myself of it.
 
I did have a use case for HV Charge mode. I was at a conference for a week and had no practical charging opportunities. Since this was in January, it was cold and somewhat snowy. I arrived with about half battery and I would use HV Charge mode any time I went out to preserve as much charge in the battery as possible. Why? Because remote preconditioning will not work if the battery is too low. I will use HV Charge mode to maintain the ability to remote precondition.

This was an unusual circumstance, but it had utility for me on this occasion.
 
Roger Lambert said:
I used HV mode on a trip from Vermont to New York City. Five hours of driving added about three bars. The Clarity manual is WAY off.
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(I assume you mean HV-charge mode.) I expect that the charge rate in HV-charge varies significantly depending on how much power you're pulling from the engine to move the car. I would expect it to be pretty low if you're cruising at 80, versus cruising at a slower speed. The little engine that could can only produce so much power and if all of it is needed to move the vehicle there's going to be less available to dump into the battery.

I don't remember the numbers (this getting-old thing is the pits) and I use HV-charge very rarely, but I was getting one bar increase every few minutes. Whatever "few" means in this context . . .
 
MNSteve said:
(I assume you mean HV-charge mode.) I expect that the charge rate in HV-charge varies significantly depending on how much power you're pulling from the engine to move the car. I would expect it to be pretty low if you're cruising at 80, versus cruising at a slower speed. The little engine that could can only produce so much power and if all of it is needed to move the vehicle there's going to be less available to dump into the battery.

I don't remember the numbers (this getting-old thing is the pits) and I use HV-charge very rarely, but I was getting one bar increase every few minutes. Whatever "few" means in this context . . .
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Yes, sorry, you are correct - I meant to say HV Charge mode. We were going about 70 -72 mph. Did not have to press the accelerator pedal much to achieve that. Perhaps I need to have the car checked out?
 
My daily commute is about 160 miles round trip. When I first started driving it in the Clarity, I did test out the HV Charge mode for about a week. I’d drive the EV mode until the battery was nearly depleted (down to 3 bars or so) then activate the HV Charge mode. On Southern California freeways, I never had any issue topping out the HV Charge - it will deactivate itself once the battery gets to a certain percentage (don’t remember the exact number, but it’s somewhere around 55% as I recall). I’d then use the EV mode again as I got closer to the office or home. I don’t really use HV Charge any more, but I never had an issue with it charging the battery as advertised.
 
Roger Lambert said:
Yes, sorry, you are correct - I meant to say HV Charge mode. We were going about 70 -72 mph. Did not have to press the accelerator pedal much to achieve that. Perhaps I need to have the car checked out?
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How many bars you had when you started HV charge? It will only charge to 12 bars, so if you had 9 already another 3 is all you get.
 
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