ICE in EV Mode ... Again

10 deg F today. Garage temp is in the 50's. ICE started in the usual 2.0 miles trip this morning. I was passing a slow car using more than half the bar, both heated seats at HIGH.

As soon as I realized the engine is running, I looked at the Discharge Control. It was showing 40 kW so it doesn't change according to the outside temp. We can't use it as a "threshold".

I got 58 MPG on the 2.0 miles trip so I used 0.035 gallon. The engine completed the warmup and shutdown before reaching the destination. The battery SOC remained about 2% higher than a pure EV trip in less colder days.

 

how many ev miles did you use?

 

I didn't look at the displayed estimate EV miles. I look at the actual battery SOC.

Normally, it went from about 85% to about 74% after 2 miles trip. Today, I ended with about 76% remaining.

 

gotcha. i'm still in the stoneage, i need a scangauge.

 

I just got mine BT adapter & Torque app. It's great, but there is definitely still some usefulness from the having a ScanGauge.

What I'm really bummed about is the lack of an export feature for the instrument overlay in the video recorder. Then it would be a killer app. Just think what I could provide for Prius info with that.

 

I think there's a plug-in for that, isnt there? On their demo videos, they show the gauge over lays and even google map overlays, if I recall correctly.

I havent tried it myself since my 4+ year old Android device belongs in the junkyard

Here it is:

Track Recorder(Torque OBD/Car) - Android Apps on Google Play

sample:

 

Looking at the reviews, the video export/record function is no longer available in the newer versions.

 

my sister in law flew back from l.a. last nite. it had been in the 80's there. when the pilot announced it was 7 in boston, there was a collective groan on the plane.

 

I think it is conditioning.

 

today i did my dump run, 16 degrees, all ev no prolemo. then, tonight, about 4 hours later, i left for work. 10 degrees, but i decided not to burn anything off before i left, wondering if there was enough warmth in the system left over. sure enough, i had no problem staying in ev, all the way to work and back.

 

Sweet!

 

Just to update.. the past few mornings have been warmer.. maybe as high as low-mid 60s about a week ago to mid 50s today. As a result, I've been back to pure EV trips in the morning, like before, employing my same routine (accelerate up to about 40.. coast downhill and then apply friction braking 2 street lights before Stop sign).

I've logged a bunch of data but havent gone through all of it yet. But I'm pretty convinced it has to do with (1) the HV Discharge Control (basically, max regen) value (which I believe is based on battery temperature) and (2) the car "knowing" if there is the potential to surpass that "maximum regen" threshold. It doesnt matter if you actually regened or not. If the car "thinks" the potential for too much regen exists, then it will start the ICE.

I've seen a difference of up to ~17 amps while monitoring the HV Discharge Control value in the mornings. Meaning, when the battery is cold (maybe, below 50F), then the max regen is ~35 amps. When the battery is warmer, max regen is ~52 amps. These numbers are relative to a fully charged battery.

I'll sort through the data when I have time and hopefully plot a graph with various battery temperatures vs. max regen current.

 

i think you're onto something track. i'm finding that a warm battery (from driving, not charging) and/or something less than a full charge, is letting me drive pure ev down to 9 degrees so far.

 

I started a new thread with answers.

Answers to those "unexplained" ICE operations in EV mode

 

I agree I take the long way for about a mile, slow drive all EV. I think this helps, but it does have a mind of it's own!

 

IMHO you have to add the regen stuff in there. Otherwise you're just addressing the temperature component at this point.

 

Good point. I updated it and also added a link to the FAQ to address other questions.

 

the bane of my ev experience has been sunday mornings. today, it was 39 in the garage and 27 outside. left with a full charge (12.4) and drove around a bit to burn of half a mile. when i got to my downhill portion, i was going 33 mph and had 11.4 left. i was 1/4" to the right of regen and the ice kicked on. the only things i can think of that are different is: 1) it's the only morning i leave (11 a.m.) and 2) my wife is with me. next sunday, i'l try burning off another 1/2 mile or so.