Part-charging the battery and "charge-alert"?

IE 11 broke it.

You can quote.....if you right click on "reply " and open it in a new tab.
Or copy and paste.

Also page refreshes aren't happening right; to see your own posts, you often must
manually refresh. I think THAT problem is not unique to IE 11 though.

 

My personal experience is that if you switch out of the EV mode (hence into the HV mode) when the SOC is above 75% the operation of the hybrid system is such that the SOC is reduced to slightly above 70% even if the coolant is hot and the terrain is not significantly uphill. This is not your usual start-from-cold situation where the reduction in SOC could well be from heating the coolant and moving the car. This is from long a long (50 mile) downhill where you can get the SOC up to 85% but if you go into HV the car manages to work it down to a little above 70%. Facts from empirical measurements are quite useful. Perhaps the different type of battery in the PiP has something to do with all this.

 

Works fine with Chrome and Firefox.

 

Just to clarify what I "think" you meant. In the regular Prius what you say is also my understanding. But the PIP clearly has a slightly different design slant to it. The PIP defaults to EV mode on startup, regardless if this if the most efficient thing to do or not (it can't predict the future and can't know if starting the ICE might be best without some user input). I've never noticed the 70% as some kind of target SOC...it is probably just a byproduct of what ends up happening from typical driving.

Mike

 

Exactly what I meant.

 

You may be right on the efficiency question, but it's a moot point because the battery pack doesn't hold enough energy to use EV mode on all the hills - you'd run out of juice very fast and be stuck with HV mode for everything. For that reason, it makes more sense to use HV for uphills and EV on level ground and downhill runs.

​

 

Even if you let the engine totally warm up in the driveway with an 85% charge and then start out (and stay) in HV it will try to get itself down to 70%.

 

What documentation do you have that it "tries to get down to 70%" ??

If that really is the case, then what's the point of charging it to a level higher than that in the first place ??

I think you have drawn an incorrect conclusion from the behavior that you have observed.

 

I believe you are responding to me but the quote didn't work. Actually I haven't done any direct experiments since this discussion began its just what I remember from working the SOC up as high as possible while going down that 50 mile stretch. Next time I'm there I'll take some data.

As to why... because you can use that extra 15% of SOC in the EV mode (under 62 mph) to increase your overall mpg-e of the trip. That's especially useful if you can get to the high SOC just as you get to the flatland. You have to drive a PiP for a while in hilly country to get the feel for what works best. For trips in the flatland its just an hybrid with a nice 12 mile (almost) free ride. But in hilly country the PiP can get better mileage than the regular Prius.

 

I was replying to the post immediately above.
It remains a pain in the butt to quote with IE.

And my objection is only to the statement "it TRIES to get the charge down to 70%" and the implication that is done to somehow increase the battery life. I think that is not the case at all.

 

Here is a thread discussing it:
PiP 'burns' EV range in HV mode (not regen) | PriusChat

Could be more like 75% than 70% though (or low 70s). Many people with PiPs have observed this again and again.

You still achieve a much higher overall MPG during that time that it is getting burned off. It is trying to use more EV therefore you are using less gas. Make sense?

 

Just replied above...

I work closely with a lot of people in the tech field. Please don't use IE anymore. It is a horrid browser. I suggest Google Chrome.

 

It is too bad you don't own a PIP and have actually experienced this anomaly. I frequently partially charge to approximately 70% SOC on purpose as when I come home with zero EV left but know I won't be going out for a while. I charge up to about 9 miles EV range, that way I have some EV range available if a short notice trip to the store comes up or whatever I am ready to go. I also will fully charge then prior to departure if I have time and/or know I will be able to use a full charge.

Anyway getting to the point, when I leave with the 70% SOC I have noticed that the behavior of the ICE is more subdued, the car does NOT try to get the charge down from there like it does when you depart with the full charge (85% SOC). Based on my experience the car definitely does reduce the 85% SOC faster in less distance than if you start out with 70% SOC. I haven't taken any scientific measurements, but when you drive a PIP day to day the difference in behavior of the car is quite noticeable!!

 

Thanks for the link. I missed that thread when it was going. It was a good read. I'm still not convinced that an extended period of time is measured in hours and not days. Contrarily, I'm not convinced temperature has a bigger effect on battery degradation than extended periods at high SOC. We can only speculate why the PiP burns down to 70% SOC. Seems like the only way to get an answer is the good old scientific method. Experiment!


iPhone ?

 

Of course it does.

It will have a larger preference for battery power the higher the charge level is.
That does NOT mean that it is purposely trying to get the battery down to some lower level of charge.......except that it is saving gas by doing that.

I quit.

 

I seriously don't get this. The only way (under normal conditions) that the car can try to lower the SOC is when you press on the pedal. Are you saying that the car uses more watt-hours when I press the pedal to go a mile when the SOC is 85% as opposed to when the SOC is 70%?

Mike

 

Yes, the car decides what amount of gas/electricity to use when moving the car. This trade-off is continuously varying in hybrid operation. When the SOC is above 75% the car in HV mode uses more electricity (less gas) than usual until the SOC is below 75%. At that point the HV operation uses 75% as its upper operating level hence it may get to 70% in its normal HV SOC up/down operation.

 

OK, but I was talking about EV only mode.

Mike

 

As long is you are in the EV mode it simply uses the charge as needed. The "problem" is if you cause the car to change to the HV mode (like turning on the heater or getting the HSI momentarily into the PWR area) it will now reduce the SOC below 75% as previously described.