First real cold of the season in MD

[mczajka]

What kind of range hit, if any, can I expect in 40 degree temps? I would not use the heat. Might use the seat heaters though. I could precondition (I guess).

 

[Casualsurfer]

I moved to MD in February when it was cold, my Volt could only muster 33 to 35 miles (typically 43 to 45 miles) per charge. I'm eager to see how badly the range degrades in the winter.

 

[emv]

Cabin heat is the nemesis of an electric car. It just doesn't come cheap. Using the seats and a light jacket, if necessary, is a smart option and pretty comfy too. I wouldn't be surprised if you dropped ten miles from your summer range.

 

[nikwax]

Fire up the cabin heater and defroster while you're still plugged in. That should give you a good start.

 

[mczajka]

My Fusion Energi lets me get the car ready automatically at a specific time. Anything like this on the Spark EV? I only know about onstar remote start.

 

[Zoomit]

--deleted

 

[mczajka]

Touché!

 

[nikwax]

Just a thought this cool morning: leave the seat heaters turned on at shutdown, then the preheat will heat the seats as well. And you'll have hot buns in the morning (groan)

 

[SparkMoore]

Temps get in the 40's in my area during winter. I typically see ranges as low as 70 miles overall, when setting the cabin heater at 68 degrees and using the seat heater. If wearing a light jacket or sweater, the car warms up enough about halfway through my 30 minute commute to turn off the cabin heater. So I'd say under those conditions, a 10 - 15% drop can be expected. Note that my commute is mostly highway and I can reach speeds of 55 mph (I stick to the speed limit in winter). I pull out all the hyper-miling stops in winter that don't include riding in a cold car. But with shorter days in winter, the lights are usually on both to and from work.

 

[MrDRMorgan]

What kind of range hit, if any, can I expect in 40 degree temps? I would not use the heat. Might use the seat heaters though. I could precondition (I guess).

This is a very good question. So, I thought I would start looking into it since at least once per month I venture out far enough that I need to stop both going and returning to top off my battery so I can get home. I am concerned that the heater's impact to mileage might prevent me from getting to the charging location.

Here is my first look:

My 2015 Spark EV 2LT was fully charged yesterday and left out all night. The outside temperature this morning at 7:30 am was 46 deg. F. I set the car's heating system as follows: Inside temperature: 75 deg. F; Fan speed: 3 bars; Recirculation: set to inside air; Distribution: dash and floor; AUTO setting was off.

Then I checked the electricity information center to make sure all usage percentage values and the kWh used value were all still zero.

I got into the car, closed the door and powered up the car. The fan came on and, after a bit, started producing heat. After 10 minutes the car was nice and warm and electricity information showed I used 0.6 kWh which equates to 3.4 miles of range ( my avg. last month without heat was 5.6 mi / kWh). The guess-o-meter dropped by 4 miles too. From this result, I expect I will lose approximately 3-4 miles of range for every 10 minutes of driving with the heater on and set to a temperature ~25 deg. F above the outside temperature. I need to test a longer time to see if the power consumption drops off as the cabin temperature approaches the set point, I also need to rerun the test using outside air to see what impact a constant flow of cold incoming air will have.

If, while driving in cold weather, I do lose 4 miles of range every 10 minutes [ ~24 miles per hour of driving], one of my regular charging stations will be out of safe range. Perhaps switching to the heated seats after the cabin is warmed up will help extend the range a bit.

I ran this same test with my 2014 Spark EV 2LT that was in my garage overnight. The car showed the outside temperature was 60 deg. F and was tested using the same settings as above. The electricity information details showed I used 0.4 kWh for the 10-minute test. The one thing I noticed was the heat coming into the car was not as "hot" as what I experienced in the 2015 Spark EV. However, after the test I moved the temperature up to 85 deg. F and the heat immediately got hotter. This make me think there is a tapering off of heat (therefore power) as the cabin temperature approaches the set point.

I would like to know what you other EV drivers see and do to address this problem. Central California temperatures will eventually drop into the 30s as winter continues to move in.

 

[Zoomit]

I think you're missing a very important consideration. The battery chemistry does not produce the same energy when cold. Even if you don't use any additional HVAC, you will still see a loss in range that will vary based on the ambient temperature.

 

[Zoomit]

http://www.greencarreports.com/news/1089160_nissan-leaf-chevy-volt-range-loss-in-winter-new-data-from-canada

Good info there.

 

[dangerHV]

I'm going to try to make a list of energy consumption specifications. I'll post when I can. I'm going to see if a shunt can be inserted where battery disconnect is under the rear seat. Don't hold your breath.

David

 

[MrDRMorgan]

I think you're missing a very important consideration. The battery chemistry does not produce the same energy when cold. Even if you don't use any additional HVAC, you will still see a loss in range that will vary based on the ambient temperature.

My tests showed how much the HVAC consumed with nothing else running. While it is true that the battery capacity will vary with temperature, that should not be a variable in my very short 10 minute test. As a further test I drove about 3 miles with the heater on using the settings I used for my testing. The GOM dropped about 4-5 miles. Then I turned everything off and went back. The GOM only dropped the expected 3 miles. Granted this is not very precise but there is a difference and I am trying to estimate what range impact the HVAC will have on long drives in cold weather.

 

[dangerHV]

Hi Dr., My desire to measure the HV as well as the 12v batteries is that power comes from one or the other (or both) at different times. I like the 6 or 10 minute tests since they easily multiply into 1 hour.

David

 

[Zoomit]

I am trying to estimate what range impact the HVAC will have on long drives in cold weather.

That's great, and I'm curious about the results, but not very relevant to the OPs question, which stated he was not going to use heat.

 

[dangerHV]

My main reason for getting fairly accurate readings is to calculate how much energy is used for heat, fan speeds, seat heater(s), plus a/c, etc... To me, estimating a full charge at 18 Kwh then calculating out the accessory consumption would answer all but 1 part of the equation: Just how much energy IS ..."lost" (that's not quite the right term, here) due to battery temps below +/- 70deg F? I'd like to come up with a simplified answer to that, too.

David

IE: I'd like to be able to answer the OP's question ***WITH AN ANSWER LIKE***: "around 6% for every 10 deg below 65 if you like to keep cabin temp at 65; 3%/10deg using only seat heaters; 2%/10deg with no heat (only the temporary battery loss due to effects of cold, and energy consumed to keep battery above___ deg.)" This may not be too far off. @0deg.f, 6%x6.5=40% loss.
Myself, I wouldn't drive while freezing my butt off to "conserve" energy.

 

[MrDRMorgan]

My main reason for getting fairly accurate readings is to calculate how much energy is used for heat, fan speeds, seat heater(s), plus a/c, etc... To me, estimating a full charge at 18 Kwh then calculating out the accessory consumption would answer all but 1 part of the equation: Just how much energy IS ..."lost" (that's not quite the right term, here) due to battery temps below +/- 70deg F? I'd like to come up with a simplified answer to that, too.

David

IE: I'd like to be able to answer the OP's question ***WITH AN ANSWER LIKE***: "around 6% for every 10 deg below 65 if you like to keep cabin temp at 65; 3%/10deg using only seat heaters; 2%/10deg with no heat (only the temporary battery loss due to effects of cold, and energy consumed to keep battery above___ deg.)" This may not be too far off. @0deg.f, 6%x6.5=40% loss.
Myself, I wouldn't drive while freezing my butt off to "conserve" energy.

I am not going to freeze my butt off either - I like a warm cabin and do not want to be driving while being dressed up like an Eskimo. I think you will find that the 12 volt battery will not contribute much to the total power consumption question. Also, the closed-loop battery temperature control system may keep the battery capacity from going to extremes like is possible with the Nissan Leaf. However, I do not know much about it nor do I know what the temperature limits are.

I am going to repeat my test tomorrow morning although I am going to try a 30 minute test. 30 minutes should allow the cabin to get quite warm. I plan to record climate power consumption every 5 minutes to see if the power usage stays linear or tapers off as the cabin temperature reaches the temperature set point. I will post my findings tomorrow.

Added thought: Tuesday the early morning temperature is forcasted to be 36 deg. F. It looks like I will run a test that day too.

 

[dangerHV]

Since the 12v battery operates certain things, like the fan for example, and then requires recharging from the HV battery, it seems like it will be tricky to figure this out with a reasonable degree of accuracy. At least it's fun trying! (that's as long as I don't electrocute myself in the process. That would kind of suck)
Let us know your results, Doc.

David

 

[dangerHV]

For anyone interested in a VERY in depth discussion on thermal management...(specific to Volt, but quite similar in the Spark, I imagine) I love this stuff!... I know, I need a life.

http://gm-volt.com/forum/showthread.php?5243-Volt-thermal-management-system-temperature-band&s=bca87ba016a067bc74f432ccc5507007

David