Any tips for cold weather driving

[TNleaf]

<snip>
So, again, the climate control was off. I am concerned about the noise it made even above 30 mph today..
Raza

Raza/anyone else speculating on the sound,

I have noticed a very unnerving sound as of recent. It is NOT a normal sound from the LEAF and it is NOT my VSP (I have it turned off).

It was 18F here today and never got above 40F, so I'm certain it has to do with the cold, as I have not heard it other than when it's below freezing.

I took a video of the sound today, but the quality on wasnt the best and it was hard to pinpoint the sound in my video. I'll attempt another video tomorrow.

Recap:
Occurs at 18F-35F
VSP is OFF
Climate control is OFF
Radio is OFF
Occurs loudly at low speed (below 30ish).
Occurs while in N coasting, while under power and while regenning.

One curious thing I noticed was that the pitch/magnitude changes when I am regenning/foot is off accelerator.
Scenario: flat surface going 20 mph less than 10kW on energy usage, sound occurs. I ease off the accelerator and show slight regen, speed is about 15mph, and the pitch of the sound changes. I wonder if the sound is coming from bearrings/gears from the wheels to the motor?

Again, I will try to get a better video. I plan to contact a dealer about it if it continues.

It was 38F when I left today and the LEAF did not make the sounds... figures I would be ready with my camera and everything...

 

[DaveinOlyWA]

one point; the AC light being on means that compressor "can" run. it does not mean it is running and i can assure you it is not. it cycles on and off.

the best way to test this is during Summer. set the A/C to a low temp. run it to cool off the car. then jack the temp up 5º. the light stays on but you can actually feel when the compressor turns off.

as far as preheat; even with temps in low 20's i found 7-8 minutes to be plenty of time to get the car warm. on preheat, the fan starts at low then ramps up as heat becomes available. i timed it 4 times and it took 5-6 minutes to get to a pretty good speed. usually 2 notches below max. after that, its no time at all to warm the car.

i start preheat from my phone and it does not matter whether its plugged in or not. if plugged in, it states its running from line power.

i also have aftermarket seat heaters. the cheap seat cover kind. it takes a good 2-3 minutes before any warmth arrives so its pretty lame. my Prius has seat heaters and they work great. but cold is lesser an issue (remember Global Warming is coming!!) than humidity. so i have a defrost fan with is a 7" fan mounted to dash on passenger side (couldnt do my side without obstructing the view) which works well but it does blow a pretty good breeze right at me and it can get cold but for temps above 40º its very manageable. i just wear a coat

 

[lpickup]

one point; the AC light being on means that compressor "can" run. it does not mean it is running and i can assure you it is not. it cycles on and off.

Yes, okay, I do keep forgetting that I need to be very specific with respect to this, but I don't have an easy way to say it. I agree it means that the system is active, but the compressor can cycle on and off as needed. The same is true with ICE vehicles.

 

[ovev]

Two major factors affect your range in cold weather:


2. Temperature has a profound effect on the amount of available power the battery has, and how much regen it can accept. A battery at 10F could have a 30% drop in available power (21kWh available at 70F might be 14.7kWh available on a full charge at 10F. For example, if you can average 3.6 miles/kWh driving with the heater on, your range in the LEAF might be 3.6 * 14.7 = 53 miles on a 100% charge.

How would you know what the battery temp is? You don't. The temp gauge is just about as worthless as the GuessOmeter. But, if the car has been sitting in the cold for 8 hours, you can guess that the battery is at the ambient air temperature. If its been in a garage at 50F, your range will most likely be aligned with the 50F data (10% battery capacity loss) even if the outside air was much colder. 30F battery would be 20% loss in available capacity. That 600 pound battery, densely packed in an airtight (and waterproof) container will not quickly heat or cool to the ambient temperature.

I dont think it is true that you get that much drop in range because of low temperatures. You do loose some range, but not that much. An example: My Leaf used once 16.1kW at 0C and I then drove 5km after getting LBW. In 0C my Leaf should only had 16,8kW available according to your chart (21*80%). It should then have reached VLBW, but did not. I would think the remaining charge was approximately 13%-14%. The car was not garaged and the temperature before start was about -3C, but most of the way home it was 0C. I did however charge the car from 80% to 100% just before departure using a 240V 10A EVSE. I also preheated about 15 minutes.
I've been driving quite a lot in 0-5C temperatures and it seems to me that you loose approximately .5% for each degree Celcius and not 1% as your chart indicates. A great chart by the way.

 

[TonyWilliams]

I dont think it is true that you get that much drop in range because of low temperatures. You do loose some range, but not that much. An example: My Leaf used once 16.1kW at 0C and I then drove 5km after getting LBW. In 0C my Leaf should only had 16,8kW available according to your chart (21*80%). It should then have reached VLBW, but did not. I would think the remaining charge was approximately 13%-14%. The car was not garaged and the temperature before start was about -3C, but most of the way home it was 0C. I did however charge the car from 80% to 100% just before departure using a 240V 10A EVSE. I also preheated about 15 minutes.
I've been driving quite a lot in 0-5C temperatures and it seems to me that you loose approximately .5% for each degree Celcius and not 1% as your chart indicates. A great chart by the way.

As you know, low temperature studies in San Diego, California are not possible, so thanks for the great data point. I've purposely made simple, pessimistic guesses based on other batteries, rounded down to make a "rule of thumb".

Your data is great, and please keep track and update your cold weather data.

What was your km/kWh for your above referenced trip? Unfortunately, we do not (yet) have battery temp data, so we don't know what your battery temperature was after your charging. Maybe we can get cleaner data if you don't charge prior to driving a cold soaked car.

 

[Caracalover]

This is not exactly what that setting means. If you have have charging set as the priority, it means the climate control timer will simply NOT fire unless you have a certain battery level (I think 80%). If you have climate set as the priority it just means that it will fire regardless of your state of charge. If you are using both timers anyway, the easiest thing to do is just have it set up so your charging completes before you'll need the climate control anyway and then it doesn't really matter.

If it's cold enough, you'll draw power from the battery while pre-heating regardless of what priority you have set (again provided you have at least the 80% charge you need if you've chosen charging priority). The heater can draw more than the 3kW than the charger supplies so you'll have a net drain on the battery until the cabin warms up.

You can turn the climate control on by putting the car into "ON" mode (push the power button twice without touching the brake).

I don't have much need for pre-heating, or cooling. My experience is also based on 120V as a source, not 240. If you have the car charged to 100% and then opt to pre-heat with charging as a priorty, will you lose charge, or will the pre-heating use less energy and take longer? If you are 100% charged and have priority set to climate control, I would not be suprised to find some battery used to heat the cabin. When I had the battery charged to 80% and then pre-heated the cabin (From about 48 degrees mind you, so not really needed), I gained charge (Priorty was set to charge), so that is what I based my report on.

 

[lpickup]

If you have the car charged to 100% and then opt to pre-heat with charging as a priorty, will you lose charge, or will the pre-heating use less energy and take longer?

The priority setting doesn't control how much power is used to pre-heat (cool) or at what rate it will pre-heat (cool), just whether the timer fires at all. Once it fires it will use as much power as it needs to to do the job (and yes, this may end up draining your battery somewhat, but once the temp stabilizes, you may recover some of that loss through charging.

Of course if/when the departure time expires and/or your battery level drops past a certain amount (i.e. if you're not plugged in) the climate control may shut itself off, but again this doesn't have anything to do with the priority setting.

 

[ovev]

As you know, low temperature studies in San Diego, California are not possible, so thanks for the great data point. I've purposely made simple, pessimistic guesses based on other batteries, rounded down to make a "rule of thumb".

Your data is great, and please keep track and update your cold weather data.

What was your km/kWh for your above referenced trip? Unfortunately, we do not (yet) have battery temp data, so we don't know what your battery temperature was after your charging. Maybe we can get cleaner data if you don't charge prior to driving a cold soaked car.

It was 0.18kW/km or 5.55km/kW

 

[Nubo]

The only drawback with heated steering wheel is that sometimes it does turn off and then comes back on

This is normal. When the wheel reaches a certain temp (I think it's 68 degrees) it shuts itself off until it cools down a bit and then turns back on. The owner's manual leads me to believe the seats do not work that way as it recommends turning them off if there is not someone actually in the seat to absorb the heat, and also advises on using seat covers/blankets that may insulate the seats and cause them to overheat.

The wheel gets quite warm; the contact temperature is definitely well over body temp. It stays warm for awhile and then cuts off. The 68F may be the low setpoint where it turns back on. It's a very wide swing and far from ideal and as you can imagine it takes quite a long time to cool off that much. Even though I like the feature I'd much rather have a much smaller oscillation and more constant warmth. But who knows, maybe there's some engineering reason for it.

The seats seem to provide a constant heat.

 

[Raza]

18F this morning and I still have 4 battery temp bars; also "coqui" sits outside all night. No range problems though, Raza.

Thanks for your reply! Did you pre-heat the car before driving? I am not sure what people mean by pre-heat? Does that mean start the climate control remotely through my phone or does it mean to go outside, start the car up and run the climate control?

Raza

Either use the phone or set the timer for pre-heat to start itself, before you leave at a set time. There is also a priorty setting, so choose charge or pre-heat as priorty. If you choose pre-heat, it may draw some power from the battery, and if you choose charge but usually charge to 80% you will gain charge (11 bars instead of 10) while pre-heating, or at least that is what seems to happen for me.

I don't think that you can pre-heat the car by starting it and letting it run, since the car has to be unplugged to start it.

You are welcome for the reply

Thanks for the reply I have the 2012 model. Apparently, I was able to pre-heat the car by starting it and letting it run by physically doing so while it was charging. I was surprised as I went back to my home and the car was still running even though I had the key. When I went outside without my key, of course the doors would not unlock but the car was running and the climate control was on.

 

[Raza]

<snip>
So, again, the climate control was off. I am concerned about the noise it made even above 30 mph today..
Raza

Raza/anyone else speculating on the sound,

I have noticed a very unnerving sound as of recent. It is NOT a normal sound from the LEAF and it is NOT my VSP (I have it turned off).

It was 18F here today and never got above 40F, so I'm certain it has to do with the cold, as I have not heard it other than when it's below freezing.

I took a video of the sound today, but the quality on wasnt the best and it was hard to pinpoint the sound in my video. I'll attempt another video tomorrow.

Recap:
Occurs at 18F-35F
VSP is OFF
Climate control is OFF
Radio is OFF
Occurs loudly at low speed (below 30ish).
Occurs while in N coasting, while under power and while regenning.

One curious thing I noticed was that the pitch/magnitude changes when I am regenning/foot is off accelerator.
Scenario: flat surface going 20 mph less than 10kW on energy usage, sound occurs. I ease off the accelerator and show slight regen, speed is about 15mph, and the pitch of the sound changes. I wonder if the sound is coming from bearrings/gears from the wheels to the motor?

Again, I will try to get a better video. I plan to contact a dealer about it if it continues.

It was 38F when I left today and the LEAF did not make the sounds... figures I would be ready with my camera and everything...

Unluckily, the sound is very loud and I have the same issue with the magniture/pitch you described. Unfotunately, I can not turn the VSP off in 2012. However, I have heard VSP when the weather was warm... this sound is much more profound than VSP... even above 30 mph.. Let me know what the dealer tells you.

Also, some one said it could be 12V battery being low. I did check on a cold start and it read 11.6 volts. I am curious to know if you can check that if you have something that reads it via cigarette lighter. I used my radar detector. Also, I need to know what is the normal range for the 12V battery. I know in regular cars, they say about 13.4 volts.

Raza

 

[Raza]

Even at lower charge levels (roughly three or four charge bars), I've seen modest limits on regen if the battery is cold, i.e., after "cold soaking" in 20ish temperatures. This is to protect the battery, as it can't accept charge as quickly in the cold.

I believe that you are right. I do see Leaf's regen increases as the temp increases. This is disappointing as I have 7 miles commute and half of it was was regen when the weather was warm.. I just have to wait till spring.

 

[Raza]

Two major factors affect your range in cold weather:

1. The amount of energy used to heat the cabin. Just using seat and steering wheel heat (not climate control) saves oodles of power if you need it, but your feet get cold. You could use a 12 volt, waterproof, carbon fiber motorcycle seat heater under the pedals to warm you feet area for only 4 amps of power. The high setting will have a constant range between 120°F to 125°F. The low setting ranges between 110°F to 115°F. 1 Pad 9"x15"
Pad is approximately 1/32" thick. Length can be trimmed to any size with any scissor, width cannot be trimmed and has to stay at 9"... $70.

http://69.94.77.153/product/carbon_fiber_dual_temp_waterproof_single_pad_seat_heater_kit_sil-03.htm" onclick="window.open(this.href);return false;

As has been suggested, preheat the car with your climate control timer, or the iPhone app, or on the Internet at Carwings.

2. Temperature has a profound effect on the amount of available power the battery has, and how much regen it can accept. A battery at 10F could have a 30% drop in available power (21kWh available at 70F might be 14.7kWh available on a full charge at 10F. For example, if you can average 3.6 miles/kWh driving with the heater on, your range in the LEAF might be 3.6 * 14.7 = 53 miles on a 100% charge.

How would you know what the battery temp is? You don't. The temp gauge is just about as worthless as the GuessOmeter. But, if the car has been sitting in the cold for 8 hours, you can guess that the battery is at the ambient air temperature. If its been in a garage at 50F, your range will most likely be aligned with the 50F data (10% battery capacity loss) even if the outside air was much colder. 30F battery would be 20% loss in available capacity. That 600 pound battery, densely packed in an airtight (and waterproof) container will not quickly heat or cool to the ambient temperature.

So, in summary, any heater usage will be reflected in your miles/kWh average, and battery capacity is a factor of battery temperature. Range is simply your miles/kWh multiplied by available battery power. Don't use the climate control for longest range, and do whatever you can to keep the battery pack warm before launch into the cold.

Bon voyage.

Thank you for the information. I was looking for a warmer so the website helps as well. My main gripe is not that how much energy the heater takes. I knew that it would but my main gripe in my 7 mile commute is the noise that car makes even above 40 mph. Even below 30 mph, the noise is very profound and it is not VSP. I tried pre-heating the car for 10 minutes and of course the heater was sending off hot air but the noise did not go away. I have not yet tried driving more than 7 miles ... but I will on Sunday and will post as to when that goes away.

Thanks again for your elaborate reply!

Raza

 

[lpickup]

The wheel gets quite warm; the contact temperature is definitely well over body temp. It stays warm for awhile and then cuts off. The 68F may be the low setpoint where it turns back on. It's a very wide swing and far from ideal and as you can imagine it takes quite a long time to cool off that much. Even though I like the feature I'd much rather have a much smaller oscillation and more constant warmth.

I definitely agree. It is a very wide swing. It does get a bit too cold for my taste during it's off cycle.

The seats seem to provide a constant heat.

I had a long-ish (35 mile) drive this morning and did a little research with my...backside...and I did almost sense that maybe it was cycling as well. But no way to know for sure!

 

[Raza]

The wheel gets quite warm; the contact temperature is definitely well over body temp. It stays warm for awhile and then cuts off. The 68F may be the low setpoint where it turns back on. It's a very wide swing and far from ideal and as you can imagine it takes quite a long time to cool off that much. Even though I like the feature I'd much rather have a much smaller oscillation and more constant warmth.

I definitely agree. It is a very wide swing. It does get a bit too cold for my taste during it's off cycle.

That bugs me too. I am not sure why it has a such long off cycle. It does get too cold for me too!

The seats seem to provide a constant heat.

I had a long-ish (35 mile) drive this morning and did a little research with my...backside...and I did almost sense that maybe it was cycling as well. But no way to know for sure!

I did not feel that on my 10 minute commute. However, I plan to use the seat heat for me and my kids in the back on Sunday when we drive on our 40 minute commute - will post how if we sense that it cycles that too or not.

 

[Caracalover]

My main gripe is not that how much energy the heater takes. I knew that it would but my main gripe in my 7 mile commute is the noise that car makes even above 40 mph. Even below 30 mph, the noise is very profound and it is not VSP. I tried pre-heating the car for 10 minutes and of course the heater was sending off hot air but the noise did not go away. I have not yet tried driving more than 7 miles ... but I will on Sunday and will post as to when that goes away.

Raza

Could this sound be condensation frozen somewhere? Without the cover of an ICE's noise you hear it, and without the excess heat it rubs until friction wears it off? I am thinking of the noise frozen brakes make. Not sure if this is a possibility, but think it could be.

 

[Raza]

My main gripe is not that how much energy the heater takes. I knew that it would but my main gripe in my 7 mile commute is the noise that car makes even above 40 mph. Even below 30 mph, the noise is very profound and it is not VSP. I tried pre-heating the car for 10 minutes and of course the heater was sending off hot air but the noise did not go away. I have not yet tried driving more than 7 miles ... but I will on Sunday and will post as to when that goes away.

Raza

Could this sound be condensation frozen somewhere? Without the cover of an ICE's noise you hear it, and without the excess heat it rubs until friction wears it off? I am thinking of the noise frozen brakes make. Not sure if this is a possibility, but think it could be.

I am not sure. The noise is there and profound when the temps are around 35 F or lower. I doubt it is frozen brakes as it is there while I am driving over 35 mph. It definitely seems to go away as the temps are warmer. Two days ago, it was in 50 F and the noise was not there.
Thanks for your reply!

Raza

 

[gearhy02]

This makes me real happy I left the midwest to Southern California a long time ago!!

 

[Raza]

This makes me real happy I left the midwest to Southern California a long time ago!!

Lucky You!!! I could not tolerate the very hot and extremely cold weather in Nebraska in 2000 and I left for Oregon but then returned back to Maryland where I lived in 80s and 90s.

Raza

 

[Caracalover]

I am not sure. The noise is there and profound when the temps are around 35 F or lower. I doubt it is frozen brakes as it is there while I am driving over 35 mph. It definitely seems to go away as the temps are warmer. Two days ago, it was in 50 F and the noise was not there.
Thanks for your reply!

Raza

It is likely something that contracts with the cold weather and is likely nothing to worry about, but isolating it would be something Nissan should help you do. Have you contacted the dealer, and have they noticed it in the demo cars they have? I have never started out with the car in those temperatures, but I have driven into them and not heard anything like what you are describing.