Anybody switch the hybrid battery charge mode?

We have been playing with the CHG [charge mode].

When we start off, we have roughly 24 miles that we can travel on EV. Then just as the battery gets too low and the ICE has to turn on we shift it to CHG [charge-mode]. You can only charge it up enough for 15 miles.and it seems to take about 30 miles of driving to reach that limit. Once that limit is reached, go back to EV mode.

From that point on, for every 45 miles you drive, you can operate 30 miles on CHG and 15 miles on EV.

24 miles on EV, then 30 miles on CHG, and 15 miles on EV. After that just repeat the 30/15.

 

It would make sense that in CHG mode the ICE is running more than when it is in ECO mode.

How much more? We do not know.

Beyond the first 24 miles, if every 45 miles you drive after that the ICE is only running for 30 miles. Does that next 15 miles save you enough to compensate? I have no idea.

The only way to really tell would be to run a tank of gas all without CHG and then a full tank using CHG for 30 of every 45 miles.



My wife was commuting to work, driving 40,000 miles/year with our Prius-3. So we went through enough tanks of gas that we were able to compare real mpg to what the computer was projecting, etc. Now she is retired and stays home mostly.

So far with the Prime we are going through one tank of gas/month. A lot of our daily driving is EV.

 

At what speed have you done this? And is it a constant speed?

 

i think you are misunderstanding charge mode. you can't 'switch the charge mode'. you can enter charge mode to intentionally charge the battery from the engine while driving. you are always using regenerative braking to charge the battery.
before using charge mode on a wholesale basis, consider your charging opportunities, the cost per kWh, and the loss of motive power when in charge mode.

 

I tried CHG mode for the first time yesterday and after using it I do not understand why DC "fast" charging is not a option for Primes here in the states. Because it's clearly used for CHG mode.

I enabled CHG mode once the traction battery ran out, so starting from 0, and true to the manual, CHG mode cut out at 19.2 ev miles or 80%.

It took about 35 minutes to get an 80% charge. 35 minutes, compared to 2 to 4.5 hours
My MPG during this time went from 60.1 to 58.5, so yes, you get a hit for using it.

But (and for me this is a Big But ), since I don't (can't) have a home charger I have to rely on Public charging stations. And where I work there is no such station, I'm going to try using CHG mode going to work and EV home (21.4 miles each way)
I'll try to track if this is a losing proposition. I'm hoping for net zero.

I don't see myself using a charging station unless I have to go shopping for a couple of hours where a charging station is available.
The 2 to 5 hour time savings makes the CHG Mode MPG Hit bearable.

 

As I said, I don't have convenient access to chargers, at home or work

So by "net zero" I'm hoping that switching to and from CHG mode maintains the estimate MPG, for me, in the 58-60 range.
If it goes up, that's a good enough reason to never use the charge port again.
If it goes down, I'm going to have to figure out a charging schedule.

 

Interesting, its funny how many things are "hidden" in these cars. Is there any information/guide how to best drive these cars?
Or is it one of these situations where I could be switching into Charge mode, then back at various times, but ending up being more inefficient than if I just let the car do what it wants.
My temptation is to just hit EV Auto and never think about it again, but I also do like the idea of the game of it all.

My round trip commute is 84 miles a day, the morning is generally highway driving with no traffic, while home is often bumper to bumper crawling.

 

Getting into CHG mode requires a press and hold of about 1 second of the HV/EV button.
So setting EV Auto and "Letting the car do what it wants" never includes auto switching to CHG mode

 

I thought it's just my deja vu.
But there was already discussion about CHG mode few month ago.
Nice to replay the excitement of finding new thing.
Hybrid Charge Mode Question | Page 4 | PriusChat

 

IMO charge mode is never a good option for energy conversion. It converts chemical energy (gas) to mechanical energy to chemical energy( battery). Each of those conversions have loss. Then when you go to use the battery, You have an additional conversion loss. loss, loss and loss. From a gasoline source, very bad.

When you are in hv mode, with available battery capacity, then charging your battery with regin is capturing energy that would otherwise be wasted. Yes there are conversion losses, but that energy would otherwise be discarded anyway, that makes it a gain.

The only explanation I've heard of on using charge mode at all, is if you are driving into a region that forbids ICE, and you cannot plug in and do not have sufficient charge.

 

1. If you're driving into somewhere where you won't have a way to charge, and know you'll be making short trips. This will save engine warmup cycles for all of those short trips.
   
2. If you are about to ascend a large hill and are worried you'll run out of battery assist before you reach the top.
3. If the power is out in your house, you plan to run critical things off the car through an inverter, and would like to close your garage, you can charge outside or with the garage open, and have enough energy stored in the battery for many hours of inverter usage without having to have the ICE come on to sustain the 12V battery.
   
4. If the engine is running to power the vehicle at a very low power level (i.e. slow speed, almost-but-not-quite coasting down a hill) which is very thermally inefficient. It might be overall more efficient to work the ICE harder, pushing it up into its very thermally-efficient band and use the generated Ev range later. This remains to be seen.

 

I haven't done the math, but it seems that our Primes get better gas mileage in HV mode than an ordinary Gen 4 Prius due to the larger battery. The battery gets some charge every time you brake or coast or switch to B on a downgrade. (Driving in B is a money loser.)

I thought of that a couple of weeks ago when I was in Zermatt which prohibits ICEs. Otherwise, maybe I'd use charge mode when I was driving heavy and fast and approaching a known long upgrade. Otherwise I don't see a use for it.