How to recharge your traction battery While in drive mode

I've used it on long trips. EV mode when I hit a off ramp for a break/food/visit the worlds largest rocking chair, then charge mode once back on the highway. EV is great when passing thru major cities where the speed can change very often based on traffic so I like to keep it charged up.
Very useful.

 

Thoroughly hidden on page 83 of my owner's manual. How clever!!

I'm still not sure of the value of it. When I'm in HV mode in city driving, the car spends most of its time in EV anyway. But I do have a several thousand mile road trip stating next weekend and plan to experiment with it. I would think you'd need to be driving at a speed where the engine would be needing to run at a speed too low to be efficient, so it would make sense to run it faster and charge the battery. Which it does by itself in HV mode. But that's all just deductions based on what I know so far.

 

I've used charge mode on occasion. It works well if you are just looking to extend your EV miles for the slower parts of your trip. But there is a mpg hit for using it, as stated in the video. If there is any EV miles left, the battery will charge in HV mode, although at a much lower rate than charge mode. HV mode also uses the battery at times where charge mode will not.

 

Yeah, I’m also not so sure of Charge Mode being particularly useful, in that it’s not energy-neutral. By that I mean that you ultimately get fewer miles per gallon by driving in charge mode for a while and then in EV for a while, than you get by driving all of that in HV mode.

The only place I can think of where it might be useful is in some European towns where they literally prohibit ICEs (or at least diesel) within the town. You could then charge up on your way into that town.

What would seem to me to be more interesting would be to charge from an external energy source (e.g., a towed battery pack?) while driving.

 

It works, I tried it last week when I drove to New Brunswick. In HV mode on long stretches the car generally kept whatever charge level the traction portion of the battery had when I took it out of EV. Since my route had many small town slowdowns and stops the EV portion gradually diminished so I used charge mode to get a few more miles in the EV "tank" for when I got to the "city" portion at the end of the day.
I had no ability to plug in during the 4 days so the 30 miles EV I started with was all I had. And I used all but 8 miles of that right off the bat running in EV Auto mode. No interstate roads at that point, 25 to 50 MPH and the engine didn't start until I put it in HV mode.

Best as I could determine: Don't use it on a downhill, the engine doesn't have to run then. And don't use it on a long uphill when the car would be using both gas and electric. I don't know what conditions will create an efficiency gain being able to not use gas in a stop and go situation after you have used Charge mode.

In general, I would say it is best not to use this feature for regular commuting especially if you can EV both "ends" of your trip without running out charge until you get to your destination. In my case, that means using EV to get to the interstate then HV mode. EV mode when I get off the interstate until getting back on for the return trip, then EV home after I get off the interstate. Plug in at home to charge for the next time I go out.

 

The gloriously ironic opposite of that, of course is the area around the Greenbank radio observatory, where they maintain absolute radio silence. So *only* diesel is allowed there!

 

Where the charge mode has some value is if you are traveling to a place where you cannot charge, but you can operate for several days on EV only (perhaps a series of short trips, etc.). I can see if I travel to a remote campground area, when I get there I would prefer to be on EV for the entire time both for noise and emissions reasons. It would make sense to use the charge mode on the way there to top off the traction battery. If you can put some extra load on the ICE when it's running anyway, in exchange for not starting/stopping it multiple times at your destination, I suspect the energy balance would be pretty neutral. Even a place like Yosemite - charge on the way to the park, then if you camp at the end of the valley you can get all the way in/out and a few side trips on EV only.

 

That’s a good suggestion! My immediate thought would be to drive to such places entirely on HV, so that you can get there with nearly 100% battery (charge mode only charges up to 80% IIRC).

 

That's a good point. It may depend on how far you travel to get there and the terrain, etc. I typically don't like to keep the traction battery full in the mountains, since there is no room for regeneration to the battery going downhill if it's full. At a park like Yosemite, you could probably find an outlet somewhere to top off.

 

I heard of someone getting very high mileage that way. I didn't find the video, though. Do you have the link handy. I'd like to know more about the speeds involved and his methods.

 

Ahh Charge Mode! It is a nice tool to have in your tool chest
I have used this feature several times, initially out of curiosity, and again when waze reported a 45 minute traffic jam ahead on the parkway, I had just depleted my electric a few miles back and knew id want some electric for the stop and go.
with the traffic jam still 3 miles ahead i hit charge mode and gained approx 3 miles EV range, that plus the gradual regenerative deceleration from 75 to 10mph gave me 4.5 miles of electric to keep the ICE off in the long stop and go.
I still hate traffic jams but knowing I can keep my engine off and not burn fuel while sitting or crawling slowly for 45 minutes is GREAT!

one more trick for charge mode - to warm your car faster and defrost your windshield faster, it taxes the engine and makes lots of extra heat to charge your battery, this can be useful in certain situations.

and yes you definitely pay a penalty to convert, maybe 85% - so a mile worth of gasoline is used to generate 0.85 miles of electric

 

That’s a good suggestion there. Nevertheless, at least based upon what little I’ve done of HV mode on our P.Prime in stop&go traffic, HV mode also does a pretty good job of keeping the engine off (after warm up). That is, assuming that you keep it in Eco mode, and stay conservative with acceleration and climate-control.

 

One other note - if you utilize the dynamic cruise control in a traffic jam it works decently in EV.
but in hybrid with no electric left, I found it keeps requesting more power than necessary and turning on the engine and then a second later decide to brake,repeat this event 10 seconds or so as cars move awkwardly forward in a traffic jam. it does a great job maintaining a nice distance but i didnt like the engine coming on sand turning off as frequently as it was...
I'm sure its technically"fine" but i really like the idea of avoiding 50 or 100 engine starts by having it work a little harder to charge up the battery for an equivalent distance - then using just electric for those bursts of power the cruise control uses to keep up with the car in front of me.

 

Yeah, in traffic jams or even the slinky waves cause by too many tailgaters, the DRCC is too abrupt to be economical. I prefer to shut off cruise control and take a more subtle approach.

 

Thanks. I found that one a while after I asked you, but wasn't sure if that's the one you meant. I haven't finished watching it, so I should get back to it.

 

For the most part, I find that DRCC does well in bumper-to-bumper traffic, but yes, it’s not subtle.

Well, once you’re already in bumper-to-bumper traffic, that is. One thing I find amusingly dumb about DRCC is how it behaves as you approach a car stopped in front of you. It keeps cruising away at the programmed speed, even while the radar has detected the stopped car. Keeps on cruising toward it at full, programmed speed. Then it starts beeping like crazy at you telling you to emergency-stop! Presumably it would then slam on the emergency brakes (obviously I haven’t pushed my luck that far). In short, it doesn’t seem to be smart enough to figure out that it needs to slow down for stationary cars ahead of us.

 

Found this somewhat amusing - "today is very hot, 25C (~77F), so I am going to use the A/C or the temperature inside the vehicle will be unbearable." Perhaps on a very sunny day, but on a day like that I'm cruising with fan only. Once it gets more than 90F, then it's hot.

Up to 60 km/hr on the trip out, or 37 mph max. Everything on the road was passing him like he was standing still, so the speed limit must have been up around 80 at least. Average speed on the trip was 26.72 mph, which would explain the high fuel economy.