ICE coming on first thing in the morning

It says that right in the manual. The way I figure it, the idea of defrost is to use dry, heated air to remove moisture from the inside of the window. So, you essentially air-condition the heated air to remove humidity from it. Well, the heat pump can't run as a heater and an air conditioner at the same time, so you need the ICE to provide heat while the heat pump dries the air.

 

I finally got my engine to come on. It went down to 2 F last night and my garage was at 30 F according to the car. It was 15 F outside, but the car drove without the engine (I had the audio system off to listen for the ICE). After several miles, I pressed the EV/HV switch and the engine promptly started. For the rest of the drive, the ICE stayed on even after pushing the switch to return to EV. After a quick stop at an ATM, the ICE started when I powered the car up (EV miles displayed in the HUD were not decreasing). I stopped for breakfast for a half hour and when I drove away I was back in solid EV mode at 16 F outside temperature. Another 5 miles to finish the trip and the FROM START indicator was 100% EV for that last leg.

So as long as I don't put it in HV mode, the car seems to really want to use EV. I turned Eco mode ON for the climate control after I got home. Should have tried that when the engine was on.

 

If you turn off all heating functions at 0 degree weather it should work in EV...

 

Here is my experience from this morning. I left this morning on a full charge after fully charging the night before - car kept in 43 degree garage. My EV range said 22.4. It was 9 degrees out this morning. I ran in EV mode for a little less than 4 miles before the ICE kicked on when the temp registered 12 degrees. The EV Mode green button remained on however, and still showed 18+ miles available in EV. At no time did the EV button go off. I only knew I was in HV mode cause the KwH indicator showed no reading. After about 4 additional miles of running in HV, it went back to EV mode and stayed there until EV mileage ran out. At no time did I have any defrosters on or the heated seats, etc., just the heat set to 70.

 

The order is, as I understand it, first cooling the ambient air to below dew point (de-superheating) by the A/C and then heating it up by the ICE hot cooling liquid (superheating). This way, you get the driest air to the windshield. So, I imagine the A/C evaporator is placed in front of the heat exchanger of the ICE cooling liquid.

 

Maybe so, but doing that in freezing conditions will cause the evaporator to accumulate ice.

 

@Captmiddy Once the ICE comes on, it will not turn off until the engine has warmed up to operating temperature. After that point it will turn off until if falls below operating temperature again. It seems likely that once the car decides it has to turn on the engine, it will assume that the engine will be needed again during the same trip and will operate to keep it at operating temperature.

 

Yes, and it was that way on all the cars in which I've looked closely at the radiator.

 

Cooling down the pre-heated air will increase its relative humidity so will be counterproductive to the goal of clearing the windscreen.
Sure, at sub freezing temps the A/C becomes less and less effective and ice buildup on the evaporator's fins only adds ineffectiveness, however, at sub freezing temps the A/C is less of a need, even if the ambient cold air is saturated with water vapors, the high temp rise by the heater will make it dry enough to clear the fog.

 

Which radiator exactly have you looked at?
The A/C heat exchanger in front of the car's main radiator is the condenser. I am speaking of the evaporator and the small cooling liquid heat exchanger both used to condition the cabin. In most cars you need to do some disassembly to see them.

 

Misread your post there.
I expect the evaporator is before the coolant heat exchanger(heater core is the term commonly used for it here) on all cars for the reasons you have sited here. While dehumidifying, moisture will collect of the evaporator. If the air is heated before reaching it, the more energy the air has to pick up the moisture.

 

Be happy with your results !!! Your posts and some others experience give me some belief the Prime will satisfy my need to drive short trips in the winter on EV alone as long as I don't use heat, defrost, etc. Not everyone's Prime seem to be as capable of operating without the ICE in cold weather as yours. I think you must have a stronger battery. Maybe your car was sold soon after arrival from Japan?

 

I am not an expert but my guess is that your ICE kicked on under the conditions you state when your traction battery got cold enough after leaving the warmth of your garage. If you charged the night before and the charge did not finish shortly before your departure the battery did not have the warmth left from the heating mode built into the end of the charging cycle.

 

i drove my pip 5.5 miles to test drive a prime. the pip stayed in ev all the way there, and all the way home. 11 miles r/t, got home with .3 miles left.
the prime however, refused to stay in ev. every time i touched the accelerator, the engine would run for a few seconds. very frustrating.
does the prime have an hsi bar like gen 3? couldn't find anything similar.

 

It's like a horse, it doesn't know you yet

Was there maybe a temperature difference, i.e. was your PIP coming from a warm garage, the Prime at the dealer sitting out in the cold?

 

yes, exactly. it was 30 degrees and sunny, they didn't charge the prime, just started the engine and let it sit until warmed up. i had to force charge to put 2 miles into it.

 

Did you force charge in drive with gas pedal and brake or put it in charge mode?

 

Other than EV not fully functioning, any other impressions? That's a unique perspective you get, hopping out of a PIP and getting into a Prime.

 

hit the highway, force charge at 55 mph, noticeable drop in power, i had to gas it to keep up.