Newbie question about drive modes

[Das KONA]

Have a Kona EV but wanted a vehicle that's more user-friendly for long road trips. Picked up a 2019 Clarity Touring plugin a couple days ago. Canadian version (no power seats!)

It was suggested to me to put it into HV mode following each gas fill up, or else I'll be in EV mode by default and will run out of EV juice quickly. I'm not doubting the advice, but also not understanding the rationale.

A lot of the time I'll just be driving around town, within the EV range, and I assume I just leave it in EV mode in that case, and recharge at home as needed. Right?

On a long road trip, I had thought it would just run on the EV charge until that's gone and then revert to being a regular hybrid (presumably it switches itself into HV mode?). So what is the advantage of preserving some electric range by going into HV mode early? I think I've read it lets you have some extra power for going up big hills, but if that isn't a concern, are there other reasons?

And any other tricks to get the cheapest driving experience (without overly sacrificing other things)? I know using the heat or AC uses a lot of juice, but anything else?

Thanks, and I'll be back with more stupid questions ....

 

[insightman]

On a long road trip, I had thought it would just run on the EV charge until that's gone and then revert to being a regular hybrid (presumably it switches itself into HV mode?).

Yes, but then the smarty-pants HV mode doesn't get to pick and choose when to use engine power vs traction battery power and your overall efficiency will suffer. Once the traction battery is down to 2 bars, you have to hear the engine most of the time, which is a pain for Clarity drivers who spend most of the time driving around town in EV with the engine silent.

HV mode tries to maintain the same battery level as when you pressed the HV button. After it uses traction battery power to get over a hill, it replentishes that power to the original level (or a little bit less in some cases). When you run the traction battery down to 2 bars (or, horror, 1 bar), the HV brain doesn't have as much battery power to work with.

When I get within the indicated EV range of home, I switch to EV and use up the traction battery, knowing I'll be charging it when I get home. That preserves what gas is left in that tiny 7-gallon tank.

 

[insightman]

Thanks, and I'll be back with more stupid questions ....

The Clarity is not a simple car, so there are no stupid questions. It can be very simple--just get in and drive and never, ever plug it in. Some California people did that--they bought the Clarity just to be able to use the HOV lanes (the Clarity PHEV no longer qualifies, however).

Alternatively, you can fiddle with the modes, pay close attention to the battery level, decide when to use the regen paddle (the other paddle is useless), and never choose Sport Mode (oh, the other paddle isn't useless in Sport Mode because the regen-paddle selection persists in Sport Mode).

One more thing: If you're warming the interior of the cabin in EV, you're using a lot of battery power to make some toaster coils glow red. In HV, you get to warm the cabin with good old radiator water, saving that traction battery for traction.

Here's the revised button I created to tape over the D button so I don't forget to press the HV button after stopping on a long trip:

 

[Das KONA]

Yes, "ignorant" would have probably been more accurate regarding my questions, but it's more fun to say "stupid" once in a while.

I think I get what you're saying about a long trip. If I just start out in EV mode, there will likely be times when I'm burning electrons when the smarty-pants HV mode would have decided it was overall more fuel efficient to turn on the gas engine for a bit. And once all my electrons are gone (aside from a few harvested from regen) I'll be running on gas all the time and there would be times when it would have been more efficient to be using electrons. And it's probably pretty hard to out-think the EV mode logarithms on the fly to get more efficient usage than what it decrees.

You can tell from my use of "electrons" that I'm fairly ignorant regarding electricity in general, but I think I see the big picture now.

 

[insightman]

Yes, "ignorant" would have probably been more accurate regarding my questions, but it's more fun to say "stupid" once in a while.

I think I get what you're saying about a long trip. If I just start out in EV mode, there will likely be times when I'm burning electrons when the smarty-pants HV mode would have decided it was overall more fuel efficient to turn on the gas engine for a bit. And once all my electrons are gone (aside from a few harvested from regen) I'll be running on gas all the time and there would be times when it would have been more efficient to be using electrons. And it's probably pretty hard to out-think the EV mode logarithms on the fly to get more efficient usage than what it decrees.

You can tell from my use of "electrons" that I'm fairly ignorant regarding electricity in general, but I think I see the big picture now.

Electrons are the coin of the (EV) realm.

 

[jorgie393]

I think you actually get it quite well. It all depends on your driving pattern and what annoys you.

If you are just going to be driving around town, within the capacity of the battery—yes, I just leave it in EV, run the battery down some, then plug it in when I get home. HV mode not needed and never used. Since my work is in range of my battery in summer, this is how I drive most of the time.

If I’m going to be driving outside the capacity of the battery, then I often turn on HV mode once I’m on the highway preemptively, rather than letting the battery run out then have car auto switch. Why? Well, I like having some EV for each end of the ride (I switch off HV again when I’m getting close, if I’ll be charging). )But more importantly, if you run the battery completely out, the car will work fine but at times the engine will rev more than I like — for example When accelerating and going up a hill, and the car has decided to be stingy with battery assist because the capacity is so low. There’s nothing wrong with this, I just dislike it.

Observationally, when you hit the HV button, the car will consider that level of battery to be a setpoint. Engine will come on but It will continue To drain the battery by about another 2 miles, then it will silently use the engine a little extra to recharge those 2 miles, and repeat.

 

[leehoewonek]

Seconding the above answers, the car runs much nicer with battery charge of at least 50%. If I'm going on a long trip I'll run in EV mode for the first few minutes to make room in the battery for regen, then 100% in HV mode for the trip, then when close to home disable HV and let the battery get me home.

Two other points: On really cold days you may be better off to put it in HV sooner so you get the waste heat from the engine, rather than use battery to heat the car, if you think the trip is long enough that the engine will come on anyway. And, though the car doesn't have a specific EV mode, running it in Eco mode and not hammering on the gas will keep it in EV mode, even at speeds up to 140km/h. If you switch off Eco mode, or use Sport mode, it's more likely that the engine will come on at some point. If I'm just running around town and know I can do the entire trip on battery I use Eco to avoid the engine coming on at all.

 

[Landshark]

I think I get what you're saying about a long trip. If I just start out in EV mode, there will likely be times when I'm burning electrons when the smarty-pants HV mode would have decided it was overall more fuel efficient to turn on the gas engine for a bit. And once all my electrons are gone (aside from a few harvested from regen) I'll be running on gas all the time and there would be times when it would have been more efficient to be using electrons.

In HV Mode you will still be running on electrons whenever Engine Drive Mode is not engaged. The car burns gas to make electricity which goes to both the electric motor and battery as needed.

What is at issue here is the gas powered engine/generator can only provide enough electricity to produce about 60hp. The batteries can provide enough electricity to produce about 121hp. Once the batteries are depleted, or nearly depleted, you’re left with 60hp to propel a 4000lb vehicle. That pretty much eliminates the possibility of perceptible acceleration.

What makes matters worse is that the engine speed (RPM’s) is completely disconnected from anything the car is attempting to do. Some owners have been scarred for life from this experience. Image a CVT on steroids, or a clutch slipping without the odor.

Experienced owners have learned to maintain a certain amount of charge in order to avoid an unpleasant driving experience. You may wish to experience what I’ve described above and then make an informed decision on how you prefer to operate the vehicle.

As far as operating “cheaply”, that will depend on what you’re paying for gas v electricity. For some, it’s basically a wash. On the East coast it has been, and may now be, less expensive to operate exclusively on gas rather than electricity. On a long trip you’ll be using mostly gas. I’d imagine it would be most efficient to preserve some charge in order to keep the engine from revving unnecessarily to propel the car and restore lost charge. You’ll also get much better fuel economy by driving 60-65mph rather than 80mph.

 

[Das KONA]

Lots of good information there folks. Thanks