PiP 'burns' EV range in HV mode (not regen)

yes, but everyone seems to have different experiences. my first 4 miles of driving are very ev friendly and it's difficult to even get the ice to come on. in the summer, when i start with range of 16, i'm down to about 12 when i hit the highway, all hv mode. some say the ice then recharges the battery, but mine does not.

 

I think it is normal. Mine uses some of the EV range indicated while driving in HV mode, and replaces it off the running of the ICE. I have observed this when driving with no braking needed. However, just like the OP's, it tends to stay at about 3-4 miles below the full charge level I had when I started the trip, unless I get some downhill or brake regen going. I'm not an engineer, nor do I play one on tv, so I'll leave the technical explanations to the guys on here who really understand how the systems work. For me, it comes down to the fact that the car seems to have the ability to figure out what works best for the driving conditions, so I don't have to worry about it.

 

Yup, normal. Full charge SOC is 85% so it will try to go down to more comfortable 75-80%.

Thats when full power regen is allowed as well.

 

Prius PHV is a plug-in hybrid. That means it will use the electricity in the most efficient way possible. So... you'll see EV consumption while in HV mode. It's a fundamental part of the design to achieve high MPG and clean emissions.

You'll also see the EV capacity reduced to a lower level for longevity. In other words, the "full" level of 85% is not the ideal for maximum battery life. It's in the low 70's. So, no matter how much you try to sustain a capacity above that while driving, it will consume electricity to stay at that happy place.

Kudos to you for being so observant and asking questions. The system is well thought out and there are many variables at play. Of course, when we provide more information, it tends to open a can of worms. But understanding what goes on and why certain approach decisions were made has to start somewhere.

What I find most interesting is how rapid the transition from engine to motor is when the system is warmed up. You can take full advantage of gas to accelerate and immediate switch to electricity the moment you let up on the pedal. Antagonists spin that as a shortcoming. But with a such an efficient power-split design and a small battery capacity, forcing the system to rely entirely on electricity doesn't make sense.

 

Part of the issue of the ICE running at "random" times are emissions standards that Toyota needs to comply with. This is reason that the original Volt did not qualify for the HOV decals in California: the entire battery + ICE system has to be considered, and the ICE in the Volt did not meet emissions standards to qualify for the HOV decals. The temperature of the ICE effects how well things like the catalytic converter works. So the control system for the PiP has to take into account minimizing emissions along with things like mpg efficiency. Note that mpg is not necessarily related to emissions; an SUV can burn gas at a voracious rate, and then have an aggressive emissions system scrub out the "nasty" stuff, and end up with low emissions (and low mpg).

 

You really think they design cars for the most intelligent users? Heck no, they idiot proof them.

 

Yep! I'm safe!!!
No problems here.

 

I don't think making broad statements like this is in the best interests of all those reading. It makes it seem like the car is perfect and don't question or mess with anything it does. The PIP is taking into account enery efficiency. low emissions, car longevity, battery longevity, engineering limits etc all at once in the choices it makes. This is quite different than what a conventional car does -- you push the gas pedal and it makes the engine go.

Mike

 

theory. everything discussed here is theory.

 

I think it recommends in the manual to charge it right before you use it (ie. don't let it sit there forever with full charge). Having the timer in the car is pretty much the same as Toyota saying....hey it's best to not let it sit forever at full charge. Otherwise they wouldn't have it there and just have people plug in right away.

 

As Mark mentioned already, the manual said to avoid it. The SOC for long term storage is at around 20% (HV mode with no EV miles).

 

I have a related question that I’m hoping someone can answer/explain:

I was flipping through the owner’s manual and it said to use the charging timer to prevent long term degradation or damage to the battery. But this is confusing to me because the prius stops charging itself once it’s fully charged. I know because chargepoint tells me when the car stops drawing power. I also know because if I leave the car plugged in overnight into a 110v outlet the little charging light is off in the morning and the screen tells me the car is fully charged and stopped drawing power.

So my question is why do we need to use the charging timer to prevent battery degradation? It the manual wrong? Can’t the car just stop charging itself when it’s full? Why do I need to set a timer to tell it when it should be full and stop charging?

Is the point maybe to have it only charge for 2 hours from a 110v outlet instead of three so it only charges to about 60-70% SOC instead of 85%?

Thanks in advance!

 

The point is to have it sit the least amount possible at a "full charge." Sitting at the full charge long term is not good on the battery. So ideally you would use the timer so it shuts off right before you leave.

 

Think of battery as your bladder. You don't want it near full for a long period of time, if you want to keep it healthy for as long as you can. You also don't want it too empty as well.

You can temporarily go there for the sake of more EV miles. The manual is just saying don't abuse it.

It is range vs life. The best compromise is achieved using the timer to get the best of both. No matter how you use it, the same battery warrenty applies so, perhaps the timer is to extend the life beyond 10 years / 150k miles.

 

you only need to use the timer if you are not going to use it reasonably soon after it finishes. i have never used it because i can charge and go. but if you go at seven in the morning, do you want to get up at four plug in? so you set the timer the night before to come on at 4am, so it doesn't charge up and sit full all night.

 

Makes sense. Thanks.