0 degree in EV mode

2720 Views 17 Replies 8 Participants Last post by 2002, Feb 27, 2021

Trolle

Discussion Starter · Jan 30, 2021

Here in upstate NY were are in a cold spell with nighttime temps at 0 to -3 below.

I got the car last year in late March and this is the first time I have had the car in the above conditions.

The last 2 days I have found the ICE starting up in EV mode with full charge now down to 28 miles on the meter after just 10 seconds of operation.

I have not seen posts mentioning if this is normal for these temperatures, also wondering if other owners have experienced the same behavior?

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2002

· #2 · Jan 30, 2021

Trolle said:
Here in upstate NY were are in a cold spell with nighttime temps at 0 to -3 below.

I got the car last year in late March and this is the first time I have had the car in the above conditions.

The last 2 days I have found the ICE starting up in EV mode with full charge now down to 28 miles on the meter after just 10 seconds of operation.

I have not seen posts mentioning if this is normal for these temperatures, also wondering if other owners have experienced the same behavior?

Assuming you are using the cabin heater (I know I would be!) that could be why the engine is coming on as the resistance heater has limited capability. In conditions that cold it might need supplemental heat from the engine. One way to test this would be to precondition, then start driving with maximum seat heat but no cabin heat and see if the engine still comes on. If the engine doesn't come on, then turn on cabin heat and see if that causes the engine to start.

60Hertz

· #3 · Jan 30, 2021

I live in Wisconsin and have had similar occasions where the gas engine has self started in cold weather (10F and colder) in order to provide sufficient cabin heat. It is less likely to self start if you can garage the car and use the cabin pre-condition while plugged in for 20-30 minutes prior to departure. Using ECO mode also helps by limiting output of the heater.

Trolle

Discussion Starter · #4 · Jan 31, 2021

Today it was -5 when I started the car and the ICE stated immediately.

I agree with 60Hertz, it appears to be around 10 degree and lower the ICE starts within a short time.

It most likely is that they figure the cabin heat may not be not be adequate without the ICE supplying the hot water for the core.

That is all well and good if you were driving for 20 minutes or longer.

What is wrong with the system is the fact the ICE never reaches temperature if you just need to go a few miles. I fact is not all all healthy for the ICE to only run for a short interval like that as you run into condensation problems internally that sets of in the oil.

obermd

· #5 · Jan 31, 2021

The Volt does the same thing. Turns out the Gen 1 Volt's cabin heater wasn't powerful enough to meet FMVSS requirements for windshield defrosting so the car's computer turns on the ICE and uses waste ICE heat to defrost the windshield. I suspect the Clarity does the same thing.

TomL

· #6 · Feb 3, 2021

60Hertz said:
I live in Wisconsin and have had similar occasions where the gas engine has self started in cold weather (10F and colder) in order to provide sufficient cabin heat. It is less likely to self start if you can garage the car and use the cabin pre-condition while plugged in for 20-30 minutes prior to departure. Using ECO mode also helps by lim

I also live in Wisconsin and obermd gives good advice. Pre-conditioning made a big difference for me.

lefty

· #7 · Feb 3, 2021

Your 28 EV miles after a full charge in cold weather matches exactly the lowest I've ever gotten here in Iowa during winter months.

ClarityDave

· #8 · Feb 6, 2021

Trolle said:
Today it was -5 when I started the car and the ICE stated immediately.

I agree with 60Hertz, it appears to be around 10 degree and lower the ICE starts within a short time.

It most likely is that they figure the cabin heat may not be not be adequate without the ICE supplying the hot water for the core.

That is all well and good if you were driving for 20 minutes or longer.

What is wrong with the system is the fact the ICE never reaches temperature if you just need to go a few miles. I fact is not all all healthy for the ICE to only run for a short interval like that as you run into condensation problems internally that sets of in the oil.

Could it also be that the batteries need to be warmed in order to operate efficiently? My guess is that at very cold temperatures you cannot draw as much current off the battery. So perhaps the ICE starts up to warm up the battery pack.

2002

· #9 · Feb 6, 2021

ClarityDave said:
Could it also be that the batteries need to be warmed in order to operate efficiently? My guess is that at very cold temperatures you cannot draw as much current off the battery. So perhaps the ICE starts up to warm up the battery pack.

Only thing is there is no connection between ICE and the battery, each is on a completely separate cooling system. I go into more detail about this in the other parallel thread that is running right now on this topic titled "Charge Throttling? I put a link to my post in that thread at the end of this message.

To prove or disprove either theory simply requires driving without cabin heat turned on, if ICE still comes on even without cabin heat being used, that would provide evidence for your theory. If ICE does not come on that would seem to confirm that in cold weather ICE is coming on only for cabin heat. Fortunately you can still use the seat warmer without skewing the test.

Below is a link to my post in the other thread. Although the preview for the link shows the first post in the thread, when you click the link it goes directly to my post.

www.clarityforum.com

Charge throttling

Ever see a charge like this? This was at a public Chargepoint station that I have used many times and never seen the charge throttle back like this. Usually charges right around 6kW from start until approaching near full. In this case, the charge rate dropped from 6kW to about 4.25kW very...

www.clarityforum.com

www.clarityforum.com

ClarityDave

· #10 · Feb 7, 2021

2002 said:
Only thing is there is no connection between ICE and the battery, each is on a completely separate cooling system. I go into more detail about this in the other parallel thread that is running right now on this topic titled "Charge Throttling? I put a link to my post in that thread at the end of this message.

To prove or disprove either theory simply requires driving without cabin heat turned on, if ICE still comes on even without cabin heat being used, that would provide evidence for your theory. If ICE does not come on that would seem to confirm that in cold weather ICE is coming on only for cabin heat. Fortunately you can still use the seat warmer without skewing the test.

Below is a link to my post in the other thread. Although the preview for the link shows the first post in the thread, when you click the link it goes directly to my post.

Charge throttling

Ever see a charge like this? This was at a public Chargepoint station that I have used many times and never seen the charge throttle back like this. Usually charges right around 6kW from start until approaching near full. In this case, the charge rate dropped from 6kW to about 4.25kW very...

www.clarityforum.com

Perhaps the battery pack is warmed by a resistance heater. When the battery pack is cold, you can not draw as much power from it without damaging it. Since the battery is already being used to move the car, perhaps it cannot supply enough power to also warm itself since the battery is cold. Thus, my proposition that perhaps the ICE is starting to generate power to warm the battery pack so that it can be used more fully. Just a guess...

2002

· #11 · Feb 8, 2021

ClarityDave said:
Perhaps the battery pack is warmed by a resistance heater. When the battery pack is cold, you can not draw as much power from it without damaging it. Since the battery is already being used to move the car, perhaps it cannot supply enough power to also warm itself since the battery is cold. Thus, my proposition that perhaps the ICE is starting to generate power to warm the battery pack so that it can be used more fully. Just a guess...

In terms of how things could work yes that makes sense, but only in Canada. According to the owners manual only Canadian models have a battery warmer. The manual says that the battery warmer only works while plugged in (thus ICE will not be running). However as I mentioned in the other thread there is also a vague implication in the owners manual that Canadian models can use ICE to warm the battery enough to start driving. The only explanation I can think of why this is true only in Canada is that in those situations ICE will generate electricity to power the battery warmer, which only Canadian models have.

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2002

· #12 · Feb 8, 2021

In case anyone is trying to find in the owners manual where it talks about the battery warmer in the Canadian versions of the Clarity, it's on page 466. I have also pasted a screenshot from that page below. The text gives the impression that the car must be plugged in for the battery warmer to work, but maybe what they are really saying is that you should avoid getting into the situation in the first place by keeping the car plugged in so that the battery warmer can keep the battery from getting too cold to drive. But if you don't plug in or are not able to, the other place in the owners manual (on page 109) seems to indicate that ICE can be used to warm the battery. Which as I said previously I assume in that case ICE is used merely to provide electricity for the same battery warming system mentioned on page 466. The drawback of the ICE method is that you have to wait for it to warm up the battery, whereas with the plug in method the car should be good to go whenever you are.

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ClarityDave

· #13 · Feb 9, 2021

2002 said:
In terms of how things could work yes that makes sense, but only in Canada. According to the owners manual only Canadian models have a battery warmer. The manual says that the battery warmer only works while plugged in (thus ICE will not be running). However as I mentioned in the other thread there is also a vague implication in the owners manual that Canadian models can use ICE to warm the battery enough to start driving. The only explanation I can think of why this is true only in Canada is that in those situations ICE will generate electricity to power the battery warmer, which only Canadian models have.

View attachment 569

Not trying to be argumentative by any means but the owner’s manual seems to only indicate that there is a battery warmer in Canadian models that is powered by external power and used for when the car is not running and in very cold conditions. It doesn’t specifically say that the system doesn’t have a way to warm the battery otherwise. I guess the reason I keep coming back to this is that I know my other PHEV, a Chrysler Pacifica, does indeed have a way to warm the battery and it does so without external power. I believe that it usually comes on when it’s cold outside and the car is running. In the Chrysler it shows up on the informational display as energy going to the climate control but it draws energy even when the climate control is off. It would just seem logical to me that there is some sort of battery warmer on the US Clarity models too. I could be wrong...

ClarityDave

· #14 · Feb 9, 2021 (Edited)

Here is another interesting point. On page 13 of the owner’s manual it says that under certain circumstances the engine may turn on or, if it is already on, may not turn off. One of the circumstances listed is “The ambient temperature is too hot or too cold”. There is nothing on that page that indicates this would only pertain to Canadian models. If the engine starts up when ambient temperature is too low, then why is it starting? The only reasonable assumption would be that something needs to be warmed up.

Another interesting point is on page 393. It says that sometimes the deceleration paddle will not work and the indicator will blink if you pull back the paddle. One of the reasons listed is that the high voltage battery is too hot or too cold. I think I have seen this behavior before even when the HV battery is not fully charged. But eventually the paddle starts to work. That would seem to indicate that maybe the battery was too cold and then it warmed up after a period of time and the paddle started working. Again, just a guess...

One last point. If you get a chance, read the first paragraph on this web page: Integrated Cooling System for Underfloor High Voltage Devices in PHEV

It seems to indicate a method for heating the high voltage battery.

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2002

· #15 · Feb 10, 2021

ClarityDave said:
One last point. If you get a chance, read the first paragraph on this web page: Integrated Cooling System for Underfloor High Voltage Devices in PHEV

It seems to indicate a method for heating the high voltage battery.

Yes in fact that is the system that I was describing in the other thread that I provided a link to in post #9. For those who maybe don't feel like bouncing back and forth between the two threads here is what I said in the other thread:

"For some more background, Clarity has a separate water cooling system that is shared by and used exclusively by three components - the battery, the charger, and the DC-DC converter (which powers the 12V system). In warm weather the battery is cooled by this system as the heat from all three components is dissipated through a separate radiator. You can actually see this radiator if you look through the small opening in the far left side of the front bumper (the driver side). The similar opening on the other side of the bumper has nothing there and is in fact covered.

In cold weather this cooling loop can be used to warm the battery by sending waste heat from the DC-DC converter and charger to the battery."

There is one big reason why the battery is on a completely separate cooling system than the engine, it's because heat is as much of a dangerous enemy to a battery as cold. Here you have an EV which has to coexist with a loud, obnoxious, fire belching internal combustion engine which is dumping heat in every direction. So they do everything they can to keep that engine heat away from the battery. Yes in theory there could be times when some of the engine heat might benefit the battery, but those times are rare and it would add complexity to manage heat flow from the engine to the battery. So instead they provide battery warming for U.S. and Canada by utilizing the liquid cooling system that is already in place for the battery, which can if needed use waste heat from the DC-DC converter and/or the charger to warm the battery. ICE is not involved in that process. In fact the Clarity Electric used the same system.

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2002

· #16 · Feb 10, 2021

ClarityDave said:
Not trying to be argumentative by any means but the owner’s manual seems to only indicate that there is a battery warmer in Canadian models that is powered by external power and used for when the car is not running and in very cold conditions. It doesn’t specifically say that the system doesn’t have a way to warm the battery otherwise.

It's an interesting discussion. Unfortunately since the owners manual gives only a few vague breadcrumbs all we can do is speculate on what they are leaving out.

ClarityDave said:
Here is another interesting point. On page 13 of the owner’s manual it says that under certain circumstances the engine may turn on or, if it is already on, may not turn off. One of the circumstances listed is “The ambient temperature is too hot or too cold”. There is nothing on that page that indicates this would only pertain to Canadian models. If the engine starts up when ambient temperature is too low, then why is it starting? The only reasonable assumption would be that something needs to be warmed up.

My opinion is that the something that needs to be warmed up is the cabin. If there is a hidden heater of some type in U.S. models powered by ICE that can warm the battery, no one seems to have discovered it yet. Although, I continue to maintain that in Canada the electricity generated by ICE can be used to power the battery warmer. There is no other explanation that I can think of why Canadian owners (and only Canadian owners) are told that they can sit in their car with the engine running and wait for the battery to warm up.

Srcpt

· #17 · Feb 27, 2021

This was common behavior for my 2012 Chevy Volt when temps were about 20F or less. Driver info screen reported ICE operating due to low outside temps.

2002

· #18 · Feb 27, 2021

Srcpt said:
This was common behavior for my 2012 Chevy Volt when temps were about 20F or less. Driver info screen reported ICE operating due to low outside temps.

The question that so far remains unanswered is specifically why does ICE start up in sub-freezing weather. Is it simply due to the need for more cabin heat than the resistance heater alone can provide, or is it because the battery is too cold to provide the needed driving power, or is it that the battery could provide enough power all by itself but it wouldn't be good for the battery.

Where I live it doesn't usually get too far below freezing, but my experience in those temperatures is that if I don't have cabin heat turned on when I start the car, it operates normally and ICE does not come on. My theory is that this will be true at colder temperatures also, but I don't have a way to test at colder temperatures. But so far I haven't heard of anyone testing my theory by having cabin heat turned off when they start the car (which requires turning off cabin heat prior to shutting off the car at the end of the previous drive).

Do you remember if in your Volt ICE turned on at startup even when cabin heat was turned off? Understandable if you never tested that, after all most people leave cabin heat turned on during cold weather.

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