In cold temps, ICE turns on at the begining of a trip when I have plenty EV. Why?

But, as the thread title and OP explain, our experiences here are about the PiP when it has plenty of EV left. The question is simply what is kicking the ICE on, because it isn't things we already know: heating is off, it's not excess regen, it's not what normally be considered excess speed, etc. So far, I've found nothing that contradicts the theory that it is coming on because I'm trying to draw more from the battery than it is happy to give when cold, though it would be fine if it was warm.

 

correct. i suspect jimbo has realized he was mistaken. or else, he pulled a fast one on us.

 

Well this AM it was snowing (and 26F) so with those poor driving conditions I was able to keep it at or below 22mph for the first 2.5 miles which kept the ICE from firing up. By the time I got the the divided highway portion of the trip I had burnt off enough EV power to prevent the ICE from firing even at 60mph.

In real estate it's "location... location... location!"
In the PIP it's "speed.... speed.... speed!" when it comes to the ICE firing up in cold temps.

 

A week or two ago we had at/near record low temps here, and our lows were colder than the lows of last winter. Even so, I have yet to have any unexplained ICE firing up as I did last winter.

 

i wouldn't call mine unexplained. they are definitely temp related. it's just the circumstances when it happens aren't completely understood. it is very repeatable tho, not random at all for me. without serious testing, i don't know the exact temp, battery level, throttle position, speed, recharge, etc., etc., etc.

 

I think most of it is battery temp. and rate of amp draw!

 

See, it's not repeatable for me. I park in the same spot, drive the same route every day. Every other ice trigger is repeatable, but some days it fires right up in cold weather (teens or below, F) sometimes I can drive all the way to work on electric.

 

it has to be one of the variables, or a combo that your not thinking about, or can be sensed by the car but not us. for instance, you mention teens or below. the book states 14 degrees specifically for some reason. if it's measuring all the variables and computing trigger points, we'll never know, there could be millions.

 

Oh I understand there has to be some consistent underlying logic, I just think in this case, while we have some ideas of what it is, we don't yet understand it fully. I've had times where the ice comes on at 25F and others where it stays off at under 10. For the same storage and driving conditions.

 

If it is the amp from battery, it is easy to log with Torque app.

Would be a good idea to log the 3 battery pack temp sensor as well.

 

I have read the first 5 pages of the thread and don't see a solid answer to the issue of the ICE coming on in cold weather. Some people see no change in cold weather. I can turn all of the heat controls off and the engine still comes on and stays on until it gets warm, all the while the battery is going down for ev driving. So I might start at 10.7 and as I drive the engine stays on the entire time until I have gone about 3 miles. So finally the engine turns off and I drive with EV for about 3 miles and then the engine comes on again. I could understand this if I had the heater cranked up but I can have the heater off and it seems to have no impact on the running engine. I am driving at lower speeds. Has Toyota addressed these complaints?

 

Welcome to PC.
What is your request temp setting? if not on LO, ICE may start even when 'heat controls' are off.

 

no, toyota hasn't addressed them, because they are addressed in the owners manual. also, if you look at the sticky faq's, there is a section on why the ice might fire up. it's not an ev, so there's no guarantee. all the best with your pip!

 

Best odds for the ICE to start up: park outside overnight in cold, push throttle past halfway on the HSI, drive a 2012

Best odds for the ICE to not start up: park in a garage, be very easy on the throttle when starting out, drive a 2013 or newer

 

A curved ball thrown on us??

 

Yep! the biggest thing is heated garage, makes it alot easier to keep in electric. Then light foot.

 

Or a heated outside...
Today we finally thawed out from the early morning teens/low 20's to 40F. No problem using EV up to 62mph without the ICE starting.
My recent cold weather commute of 78mpg shot right up to 92mpg with today's 40 deg temps

 

Or a heated outside...

Thats even better!

 

mmmmmmmmmm....

 

Fully charged and downhill breaking:

Is it possible to shift transmission to "N" before downhill and shift it back to "D" after? Would this disable regenerative braking and use brake discs alone? Would it harm the transmission to shift while vehicle is moving?

Please, pardon my ignorance to make these questions. My PiP is scheduled for delivery in April 2014 and I have little knowledge about automatic transmissions yet. I've had a test PiP for a couple of days. I live on the hill and the first thing in the morning after I unplug it; I have 100 yards of downhill drive.