Cold Weather Observations

[Russael]

Today, after sitting overnight in -15 F temperature, the HVB temperature is down to -2.2 F.  The estimated range is down to 15, from 25 in the summer.  As always, when it is -15 F, the Intelligent Access Key (IAK) loses its intelligence.  In order to start the car, I have to put the IAK in the backup slot.  It cannot be used to unlock the doors either.  It simply does not work when it is this cold.  Has anyone else that has left their car out in -15 F temperature overnight had this problem?

 

Do you mean the proximity sensors stop working, so you can't unlock by using the handles nor start the car, or does that also include using the fob's unlock button to unlock the doors or spring open the trunk remotely?

 

I haven't had any issues like this yet.

[larryh]

It has to be sitting out in the cold overnight when the temperature falls to -15 F or lower.  The lock/unlock buttons do not work on the IAK.  Touching the door handle does not work.  You have to use the keypad to unlock the door.  When it doesn't get above -15 F during the day at work, I haven't had a problem.  It probably hasn't been sitting long enough in the cold.  MFM connects with the car just fine and updates the EV range.  I assume I could remote start the car and unlock the doors via MFM. 

 

I wonder where the transceiver is located inside the car.  I take the IAK out of my pocket and moved it around within the car to see if that would help for better reception.  But it didn't. 

 

 

Presumably the key is in your pocket and you just came out of a warm house.  It's not the key, it's the transceiver in the car that isn't working.  Next time see if you can open the trunk with the pushbutton beside the license plate lamp.  There is another transceiver back there.

I will try locking the car and see if the transceiver for the trunk works.  There will be plenty of more cold nights this winter. 

Edited February 2, 2014 at 03:10 PM by larryh

[meyersnole]

I can not even imagine living with temps being discussed in this topic. When it gets below 20 I am hesitant to even go outside!

 

I would assume that even gas powered cars can struggle when temps drop to the negative teens?

[Russael]

It's more of a struggle to get them started unless you have a REALLY big battery or an engine block heater.  :)  Once they're running, they're fine... they just consume more gas.

[larryh]

The Fusion Energi starts immediately no matter what temperature it is.  Cars with normal batteries take some effort to get started.  Many have to be jump started. 

[Hybridbear]

This morning it was 19 F.  I preconditioned the car using the 120 V charger.   Preconditioning took 1 hour.  As usual, the interior felt no warmer after preconditioning had completed.  I recorded the following measurements before and after preconditioning:

 

Parameter     Before   After

HVB Temp      19.4 F   24.8 F

HVB SOC       98.4%    95.8%

HVB Volts     341.5 V  341.6 V

Coolant Temp  19.4 F   19.4 F

Interior Temp 23.0 F   39.2 F

 

Preconditioning warmed up the HVB battery by 5.4 degrees F.  It required about 1.5 kWh of energy to do that.   Preconditioning in cold weather with the 120 V charger is probably a complete waste of energy.  I doubt that you can recover an additional 1.5 kWh of energy from the battery by warming it a mere 5.4 degrees F.  In addition, the cabin interior was no warmer than when preconditioning started so I don't think you are saving the HVB from using much energy to heat the cabin.  I'm not sure how the car is measuring interior temperature, but it thinks it warmed up the interior by 16 degrees F.   Also, the coolant temperature that is being measured must be coming from some other place than what it shown in ET mode.  Preconditioning did not change the coolant temperature. 

 

While charging the car, I observe the HVB battery voltage and current to be 341.5 V and -3.0 amps.  Of the 1365 kW of power being consumed by the 120 V charger, 1024 kW is making it into the battery.  That is 75%.  I wonder if the efficiency would be better if the HVB were warmer. 

 

Note that I didn't actually look at the Kill-A-Watt meter to verify the power being consumed.  So I'm not sure if the 75% number is correct.

The interior temp sensor appears to be located near the rear window. It tends to read much warmer than the actual interior temp after you have been driving for awhile. With outside temps of <10F and HVAC set to 68F the interior temp on the ScanGauge would read something like 75-85F after driving for 45 mins on the interstate. The rear window area appears to be a spot of warm air in the car, likely due to the HVB fans circulating air back there. Passengers have commented that the back seat gets quite hot on long trips like that, likely due to the HVB cooling fans. It appears that the interior temp reading might measure the temp of the air being circulated to cool the HVB.

 

I see in the owners manual regarding the left display:

 

Coolant Temp – Indicates engine coolant temperature. At normal operating temperature, the level indicator will be white and will be in the normal range (between “H” and “C”). If the engine coolant temperature exceeds the normal range, the level indicator will change to red to indicate that the engine is overheating. Stop the vehicle as soon as safely possible, turn off the vehicle and let the engine cool. The thermometer indicator next to the gauge will illuminate in blue or white to indicate the following:

• Blue thermometer - This indicates that the hybrid system is not warm enough to allow EV operation. The gasoline engine will run continuously when the indicator is blue. During silent key start mode, the thermometer indicator will be blue, but the gasoline engine will not run. This is the result of the vehicle computer allowing the engine to be cooler during the silent key start period. This is normal operation and does not indicate a problem with your vehicle. After the first engine start the indicator will turn white when the gasoline engine is warm enough to turn off.
• White thermometer - This indicates that the hybrid system is warm enough to allow EV operation. If the vehicle operates on battery power long enough, it is possible that the gasoline engine may need to run to keep the system warm. In this case, the thermometer indicator will revert back to blue.

On my return trip home this afternoon, the thermometer was always white, even when the EV icon was yellow, and later, after EV Now and EV Later modes of operation were disabled.  So this does not appear to be implemented correctly.  I wonder if silent key start mode is what they were referring to in the previous post regarding overriding normal priorities to run in EV mode when starting out from a frequent destination and the mode is set to EV Now.

It appears that this functionality was never built into the Energi models. Our FFH would do this when we first got it. This feature was removed in the PCM update. The thermometer would even turn blue again if the ICE cooled off enough while running in EV mode in the hybrid. This was very useful to me in managing my use of the ICE in winter. Now I have to use ET Mode more to see the coolant temp.

 

My conjecture so far is as follows:

 

When you start out from a frequent destination, the ICE starts immediately when the coolant is below 0 F.  When it is between 0 F and 10 F, you get to drive 2.0 miles in EV mode before the ICE turns on.  If it stays above 10 F, you can run in EV mode.   However, as soon as the coolant temperature falls below 0 F, the ICE turns on.

 

Once the ICE turns on, it remains on until the engine coolant temperature exceeds around 100 F.  If the engine coolant temperature falls below about 70 F, it comes on again.

 

This all assumes the heater is off.  I'm not sure how it works with that turned on yet.

 

So, to stay in EV mode, I think you want to keep the ICE as warm as possible.  A heated garage or an EBH.

Do you think that the car tracks your frequent destinations even if EV+ is off?

 

It has to be sitting out in the cold overnight when the temperature falls to -15 F or lower.  The lock/unlock buttons do not work on the IAK.  Touching the door handle does not work.  You have to use the keypad to unlock the door.  When it doesn't get above -15 F during the day at work, I haven't had a problem.  It probably hasn't been sitting long enough in the cold.  MFM connects with the car just fine and updates the EV range.  I assume I could remote start the car and unlock the doors via MFM. 

 

I wonder where the transceiver is located inside the car.  I take the IAK out of my pocket and moved it around within the car to see if that would help for better reception.  But it didn't. 

 

I will try locking the car and see if the transceiver for the trunk works.  There will be plenty of more cold nights this winter. 

Interesting. My parents have not had this issue with the C-Max Energi on the -15F nights. I haven't seen any C-Max Energi owners or FFH owners report this issue either. For my parents' C-Max Energi, MFM stops working when the temp is super cold. Using the key fob to lock/unlock the car will wake it up so that MFM can connect to the car. MFM struggles to connect to the car with ambient temps below 0F even when the car is warm from being driven. When I have driven the car and have wanted to use my cell to start it from inside a store before leaving, I have found that with ambient temps below 0F the MFM app won't connect.

[larryh]

The interior temp sensor appears to be located near the rear window. It tends to read much warmer than the actual interior temp after you have been driving for awhile. With outside temps of <10F and HVAC set to 68F the interior temp on the ScanGauge would read something like 75-85F after driving for 45 mins on the interstate. The rear window area appears to be a spot of warm air in the car, likely due to the HVB fans circulating air back there. Passengers have commented that the back seat gets quite hot on long trips like that, likely due to the HVB cooling fans. It appears that the interior temp reading might measure the temp of the air being circulated to cool the HVB.

 

It appears that this functionality was never built into the Energi models. Our FFH would do this when we first got it. This feature was removed in the PCM update. The thermometer would even turn blue again if the ICE cooled off enough while running in EV mode in the hybrid. This was very useful to me in managing my use of the ICE in winter. Now I have to use ET Mode more to see the coolant temp.

 

Do you think that the car tracks your frequent destinations even if EV+ is off?

 

Interesting. My parents have not had this issue with the C-Max Energi on the -15F nights. I haven't seen any C-Max Energi owners or FFH owners report this issue either. For my parents' C-Max Energi, MFM stops working when the temp is super cold. Using the key fob to lock/unlock the car will wake it up so that MFM can connect to the car. MFM struggles to connect to the car with ambient temps below 0F even when the car is warm from being driven. When I have driven the car and have wanted to use my cell to start it from inside a store before leaving, I have found that with ambient temps below 0F the MFM app won't connect.

The IAK does not work when I am up North, outside the cities, where it is much colder.  I haven't had a problem when I am in the city.  I don't know what would happen in EV+ is turned off.  I would have to experiment. 

[larryh]

The trip took 15 minutes.  The ICE ran for 4:12 minutes, 8:42 minutes after the trip began.   It ran at a constant 1500 rpm the entire time, even though speed varied from 0 to 50 mph.  The ICE consumed an average of 0.0158 gallons/minute, or 0.066 gallons of gas.  (I’ll have to see what happens if I use the EBH).  The HVB temperature rose from 32 F to 46.4 F.  The HVB SOC fell from 96.7% to 66.4%.  The coolant temperature was 10.4 F when the ICE started, rose to 111.2 F, and then fell to 104 F. 

 

From the following post, it appears the purpose of the mode in which the engine runs at a constant 1500 rpm is to warm up the engine faster and reduce emissions:

 

http://fordcmaxenergiforum.com/topic/2255-city-vs-hwy-commute-using-mfm-data/?p=17519

Edited February 5, 2014 at 11:00 PM by larryh

[larryh]

I think the car has two priorities when its cold, i.e. below about 10 F.  It wants to keep the HVB and the ICE warm. 

 

1.  The HVB needs to be warm to supply adequate power.  See the following post which shows the maximum power output of the battery vs. temperature: "http://www.fordfusionenergiforum.com/topic/1683-obd-ii-data-for-hvb/?p=11084".

 

2.  The ICE needs to stay warm.  Presumably because the Ford engineers assume that you want to be warm and the ICE is required to to run to warm the coolant needed to heat the cabin.  The electric heater is not adequate for really cold temperatures.  If climate control is turned off or the temperature is set to LO, then the ICE runs until the coolant reaches about 105 F.  When the temperature drops below about 60 F after the ICE turns off, the ICE runs again to warm the coolant back up to 105 F.   If the climate control temperature is set to 60 F or higher, then the turn on and turn off thresholds are much higher.  So the ICE will run longer.

 

If you use EV Now mode and start from a frequent destination, such as your home or work, and the HVB is not too cold, you should be able to drive the first couple of miles in EV mode before the ICE turns on for the first reason above (to keep the coolant warm). 

 

So to minimize the ICE from running in the Winter, you need to keep both the ICE and the HVB warm.  You can do this by parking in a heated garage, or an attached garage which is generally warmer than the outside temperature.  You can use an engine block heater to pre-warm the ICE coolant.  Then the ICE will turn on when the coolant temperature drops to around 60 F to warm it back up to 105 F.  That is better than the ICE coming on right away and having to warm the coolant from 0 F to 105 F. 

 

You can precondition the car.  That warms up the HVB by about 4 - 5 F and reduces the need to use heat to warm the cabin, i.e. you can set the climate control temperature to LO.  Ford should have provided a battery heater to warm up the HVB. 

Edited February 7, 2014 at 11:08 AM by larryh

[Dune]

I'm getting roughly half of the warm weather EV range here in our coldest winter in a long time.  Attached garage, unheated.

Taking the car in on Monday to address the Go-Times issue, though as I'm most often plugged into the 120V charger in the morning (My wife's Volt on the 240) I'll have to see how that compares to just starting it remotely.

[larryh]

The 120 V charger is not going to do much to precondition the car when it is cold.  You need the 240 volt charger when it is cold. 

[Dune]

Guess I'll stick with remote starting then as it seems to work fine with the 120v.  If I really wanted to be industrious, I'd come up with a script to automate remote starting it from the website.  Not sure why they didn't take that route to begin with instead of or in addition to the go times.

[larryh]

Guess I'll stick with remote starting then as it seems to work fine with the 120v.  If I really wanted to be industrious, I'd come up with a script to automate remote starting it from the website.  Not sure why they didn't take that route to begin with instead of or in addition to the go times.

I would not recommend automating remote start.  You can't guarantee where the vehicle will be parked when the script executes (you might forget to disable the script when you don't want to remote start the car).  The ICE may turn on using remote start, even when the car is plugged into the charger.  If the script executes when the vehicle is in an enclosed area, then carbon monoxide poisoning could result.  Although, I would hope it would require the ICE to run longer than 10 minutes for carbon monoxide poisoning to occur, the length of time the car runs with remote start. 

Edited February 7, 2014 at 03:51 PM by larryh

[Dune]

Point well taken, and thanks.  I wrote that realizing that I would never find the motivation to become that industrious, but someone to whom that kind of coding would be simple might consider it.

 

Oh, and you are absolutely correct about the ICE coming on even if the vehicle is plugged in.  Mine did that both yesterday and today as it was in OMM.

Edited February 7, 2014 at 04:18 PM by Dune

[larryh]

I think the car has two priorities when its cold, i.e. below about 10 F.  It wants to keep the HVB and the ICE warm. 

 

1.  The HVB needs to be warm to supply adequate power.  See the following post which shows the maximum power output of the battery vs. temperature: "http://www.fordfusionenergiforum.com/topic/1683-obd-ii-data-for-hvb/?p=11084".

 

If you use EV Now mode and start from a frequent destination, such as your home or work, and the HVB is not too cold, you should be able to drive the first couple of miles in EV mode before the ICE turns on for the first reason above (to keep the coolant warm).

 

Note that when it is below 0 F, generally after the first couple of miles, the EV mode selection menu pops up with the EV Now and EV later icons crossed out.  I can no longer select EV Now or EV Later modes.  The car now gives preference to using energy from the battery over using the ICE.  That is fine for my 8 mile commutes when I have adequate EV range from the battery for  the trip to work and home.  However, it is not fine for my 60 mile commute on the freeway.  Normally, I reserve the battery for EV mode later when I get off the freeway.  But when it is below 0 F, EV Later (as well as EV Now) is disabled.  I am forced to use up the HVB energy on the freeway.  The car wanted to run entirely in EV mode on the freeway with the ICE coming on periodically just to warm the coolant backup up.  It is generally more efficient to use the ICE on the freeway and reserve EV mode for slower speeds.  It did warm up the HVB from about 23 F to 57 F.  Even after the HVB temperature warmed up to 57 F and the ICE warmed the coolant to 120 F, I was still not able to select EV Now or EV Later.   The HVB was depleted after 21 miles.  The first six were on city streets.

Edited February 7, 2014 at 09:28 PM by larryh

[Hybridbear]

Note that when it is below 0 F, generally after the first couple of miles, the EV mode selection menu pops up with the EV Now and EV later icons crossed out.  I can no longer select EV Now or EV Later modes.  The car now gives preference to using energy from the battery over using the ICE.  That is fine for my 8 mile commutes when I have adequate EV range from the battery for  the trip to work and home.  However, it is not fine for my 60 mile commute on the freeway.  Normally, I reserve the battery for EV mode later when I get off the freeway.  But when it is below 0 F, EV Later (as well as EV Now) is disabled.  I am forced to use up the HVB energy on the freeway.  The car wanted to run entirely in EV mode on the freeway with the ICE coming on periodically just to warm the coolant backup up.  It is generally more efficient to use the ICE on the freeway and reserve EV mode for slower speeds.  It did warm up the HVB from about 23 F to 57 F.  Even after the HVB temperature warmed up to 57 F and the ICE warmed the coolant to 120 F, I was still not able to select EV Now or EV Later.   The HVB was depleted after 21 miles.  The first six were on city streets.

This is very confusing...it appears you would have to select EV Later first. I know that's not what you want to do when your first few miles are city streets, but perhaps that's what's needed to save your HVB for later so that it doesn't deplete it on the highway. Perhaps this would allow you to stay in EV Later when you hit that 2-3 mile point rather than crossing it out.

Edited February 8, 2014 at 01:40 PM by Hybridbear

[larryh]

Yes, it is confusing.  It states that EV Now is not available, yet it runs in EV mode anyway and now there is no way to stop it from running in EV mode until the HVB is depleted.  I don't think it matters what mode I select, I believe the mode selection screen with the EV Now and EV Later selections crossed out pops up in all modes. And it pops up at anytime throughout the trip, not necessarily at the beginning.  Sometimes it happens near the end of the trip when the HVB and ICE are all warmed up.  Why didn't it do it at the beginning when everything was cold?  I haven't figured out what causes the car to do that other than the outside temperature is below 0 F, plus some other unknown criteria. 

Edited February 8, 2014 at 07:39 PM by larryh

[larryh]

Presumably the key is in your pocket and you just came out of a warm house.  It's not the key, it's the transceiver in the car that isn't working.  Next time see if you can open the trunk with the pushbutton beside the license plate lamp.  There is another transceiver back there.

The Intelligent Access Key did not work again this morning at -10 F.  I could not open the trunk with the pushbutton either.  I will have to visit the dealer.

[larryh]

It appears that when the HVB is cold, the ICE is used to slow down the car in addition to regenerative braking when shifting into L.  This morning it was 0 F.  The HVB temperature was 14 F when I shifted to L to stop.  The maximum power that can be applied to charge the HVB at this temperature is 23.25 kW.  After the power being applied to the HVB reached about 21.4 kW (I am taking readings every three seconds so I don't know the peak power that applied to the HVB), the ICE turned on.  The rpm was around 1500 rpm.  The ICE consumed very little, if any fuel, during deceleration. 

 

Next time I will try seeing what happens when I apply the brakes.  I wonder if the ICE is used to slow down or the friction brakes are used when power from regenerative braking exceeds the maximum charge limit for the HVB.

[Marc]

Yes, it is confusing.  It states that EV Now is not available, yet it runs in EV mode anyway and now there is no way to stop it from running in EV mode until the HVB is depleted.  I don't think it matters what mode I select, I believe the mode selection screen with the EV Now and EV Later selections crossed out pops up in all modes. And it pops up at anytime throughout the trip, not necessarily at the beginning.  Sometimes it happens near the end of the trip when the HVB and ICE are all warmed up.  Why didn't it do it at the beginning when everything was cold?  I haven't figured out what causes the car to do that other than the outside temperature is below 0 F, plus some other unknown criteria.

 

I've experienced that if I start in EV Onlly mode. If i start in Auto instead, then all the modes are available to me. I gernally start out in Atuo for the first 3 surface stree miles, then EV Later for around 6 higher speed miles, then switch back to auto for about 7 miles of rush hour stop and go, then back to EV Later for a bout 5 high speed miles before finishing off in Auto for another 3 miles of surface street driving. This leaves me with about half a battery for my trip home which is basically everyting I've talked about in reverse.

 

In my case I notice the mode lock out when I started the day in EV Now and when I got to the bottom of the large hill from my house when I had used L to go into a higher regen, it must have needed to fire up the ICE to provide engine braking instead of regen braking and I no longer had control over any modes...

[larryh]

It appears that when the HVB is cold, the ICE is used to slow down the car in addition to regenerative braking when shifting into L.  This morning it was 0 F.  The HVB temperature was 14 F when I shifted to L to stop.  The maximum power that can be applied to charge the HVB at this temperature is 23.25 kW.  After the power being applied to the HVB reached about 21.4 kW (I am taking readings every three seconds so I don't know the peak power that applied to the HVB), the ICE turned on.  The rpm was around 1500 rpm.  The ICE consumed very little, if any fuel, during deceleration. 

 

Next time I will try seeing what happens when I apply the brakes.  I wonder if the ICE is used to slow down or the friction brakes are used when power from regenerative braking exceeds the maximum charge limit for the HVB.

When the HVB is cold, applying the brakes does not start the ICE when regenerative braking power exceeds the maximum charge limit for the HVB.  Instead, the friction brakes are applied so that the power from regenerative braking does not exceed the maximum charge limit.  To get a 100% braking score, you can't brake as hard when the HVB is cold.  So that is yet another reason why MPGe is lower when it is cold.  It is harder to recapture the maximum possible kinematic energy when braking. 

Edited March 1, 2014 at 03:20 PM by larryh

[larryh]

The following plot illustrates the loss of efficiency of regenerative braking with colder temperatures for a 7.8 mile commute to work.  When it is in the 70's, about 2.25 miles of my EV range comes from regenerative braking.  When it is below zero, about 0.75 miles of the EV range comes from regenerative braking.  Thus when it is warm, 2.25/7.8 = 29% of the EV range results from regenerative braking.  When it is cold, 0.75/7.8 = 10% of the EV range results from regenerative braking.  So, I am losing about 19% of EV range when it is cold because regenerative braking is less effective. 

 

Edited March 12, 2014 at 08:35 PM by larryh

[larryh]

I found a block diagram showing the cooling system here in the section entitled HEV/PHEV Cooling System Diagnostics:  https://qa2k3.motorcraftservice.com/vdirs/diagnostics/pdf/OBDSM1303_HEV.pdf

 

This is an excerpt from the document:

 

The cooling system in the Plug-in Hybrid has been designed to include two functional cooling loops. This system is designed to maximize cooling efficiency when the vehicle is running on either the gas engine or the electric motor. The system operates in one of two different modes. 

 

The first mode is the main or "combined" cooling loop mode which provides coolant flow through both the gas engine and the cabin heater core. While in this loop, both the gas engine and an electric heater can be used to maximize the heat transfer to the coolant thus providing both an increase in the engine metal temperature and heat for the vehicle cabin. 

 

The second cooling mode is the "isolated" loop mode where coolant flow through the cabin heater core is isolated from the engine block. This loop is intended to provide cabin heat when the gas engine is not running. Coolant flow is maintained in the "combined" loop by default (isolation valve de-energized), and by energizing the isolation valve coolant flow is maintained in the "isolated" loop.  

 

So preconditioning uses the isolated loop where the coolant is circulated through the electric heater and heater core, isolated from the engine block. 

 

An Engine Block Heater heats the engine block and coolant outside of the isolated heater core loop and thus will not help in heating the cabin during preconditioning.  Preconditioning and the Engine Block Heater operate independently heating different parts of the car:  preconditioning heats the car's interior and the Engine Block Heater heats the engine itself. 

 

There are two electric pumps, one for the main coolant loop and one for the isolated loop for the heater core.  I wonder what happens when we turn climate control off.  I assume that the pump for the isolated heater core loop turns off.  But then is the heater core coolant no longer isolated when climate control is off?  Does it mix with the cold engine block coolant that has not been warmed by preconditioning?  If the isolated loop is no longer isolated, then the heater will have to work harder when climate control is turned back on to heat the colder coolant that has now entered the isolated coolant loop for the heater core. 

The engine temperature display in the car shows the temperature of the coolant in the heater core loop, and not the temperature of coolant in the main loop.  So if the electric heater is on, the car may show the engine temperature to be around 140 F.  However, if the ICE has not actually run, the coolant temperature for the engine is really still only the outside temperature. 

[Russael]

Curious... at what temperature does the engine loop open?  Does the ICE need to reach that temperature first, or will the car start circulating some of that hot coolant through the block to bring it up to temperature faster (using both the electric element plus the residual heat from the ICE)?

[larryh]

The Electric Heater heats the coolant in the heater core loop to about 140 F.  It appears that the valve between the main engine loop and the heater core loop opens when the engine coolant temperature reaches 140 F.  The engine coolant pump is on whenever the ICE is on.  When the engine coolant temperature is below 140 F, the engine coolant pump turns off when the ICE turns off.  When the engine coolant temperature is 140 F and above, it remains on, even when the ICE is off, as long as the heater is on.    Turning climate on and off, turns the engine coolant pump on and off when the engine coolant temperature is 140 F and above. 

Edited April 12, 2014 at 05:04 PM by larryh