Cold weather

I live in western Canada and after a mild winter we now have some really cold temperatures this week. Does anyone have experience with daytime high temperatures in the -30 Celsius range? Yesterday the Leaf worked very well, with the exception of the range which was reduced to about 30 miles (50 km) from the more typical 90. Would love to hear about other experiences in extreme cold, particularly any experience with cold soak time. My car will likely be outside for 8 or 9 hours today in -30 weather.

Take a look at this thread:

http://www.mynissanleaf.com/viewtopic.php?f=31&t=7597

Depending on the humidity in your area, you can try keeping the climate control in auto a cooler setting or turning it off for a few minutes at a time with the on/off button; When off, change the air source to Recirculaton to avoid cold air coming in by your feet as you travel at speed. Running the climate control after preheating, keeps the liquid warm but without using too much power. Just don't leave the c/c off for too long or it will take time to warm up again when you turn it on next time.

Use your heated seats, it makes a big difference and help you use less cabin heating.

Plug it in during the day using your portable charging station; even if you are not planning on charging, the battery warmer will use power from the grid instead of the traction pack. Also, you can turn on the climate control from your computer at work or your phone and preheat before driving home (when running on battery, the climate control only runs for 15 minutes, when plugged it, it runs for up to 2 hours).

Charging the battery is a chemical reaction that creates heat; if your car is plugged it, even on 120V, you can request to start charging an hour or two before leaving (assuming you don't "need" any more charge for the day) and warm up the battery internally.

This is all to say that the battery warmer and cabin heating uses a lot of power, as much as 4-6kW, which can be significant if you think that the motor can be using 20kW when cruising.

Talk about extremes...I went from driving in 110 degree heat to 50 and was pretty shocked in what cold weather does to a Leaf battery charge..I could just imagine what its like to drive in cold weather states bordering Canada..

I normally can do 2X60 mile runs on one full charge..One day I left the house with 65 miles left of charge,doing the summer that would be a no problem drive on my 60 mile commute,doing the winter its impossible to drive round trip on a 60 mile charge..

My secure miles for my 60 mile job commute in Phx AZ..
Summer time,a 60 mile charge will get me 60+ miles...
Winter time, a 60 mile charge will get me 50 miles...

I've continued using my leaf all week with temperatures consistently in the -20's and -30's Celsius. On days with a high temperature of -30, the range was reduced to as little as 25 or 30 miles on a charge. Warming the car up in a heated garage helped immensely. I believe the constant cold temperature just reduces the available battery capacity to almost nothing. I would be curious to know if this is actually the case, or whether the car is just protecting itself by not allowing the battery to be drawn down much?

The range estimate provided by the computer is also very inaccurate when dealing with temperatures this low. It is always a little wonky, to say the least, but in extreme cold it seems to be off by as much as 50 or 70%.

On the other side, the car hasn't left me stranded and it worked well while I was driving. No problems on the road. Today the temperature was up as high as -20 Celsius and while the range was still reduced it was much closer to what I would call normal for winter operation.

Great data. Are you interesting in trying this out?

http://www.mynissanleaf.com/viewtopic.php?p=167334#p167334" onclick="window.open(this.href);return false;

I would give it a try if I can arrange the time and weather. I have essentially done the test this week, but not in one trip. I typically made between 2 and 4 trips a day which would change the overall results as the battery would have to rewarm the glycol each time I started a trip. I never reached the turtle stage, but was down to one bar or less on the battery gauge.

Do you happen to know how the on board computer estimates range and how temperature would affect it? While not terribly accurate in the best of times, at least in my experience, after a cold soak it was ridiculously off the mark. I'm wondering if the car is attempting to protect itself by limiting the discharge of the battery in cold temperatures.

our temps aren't nearly as cold as you guys, but I have found that using the preheat function to do more than just heat up the air helps a lot. I'm not afraid to leave it on for an hour +. I don't know if it will work in extreme cold, but I charge to 80% then preheat, which heats and charges the battery, often to 100%. I've been going from 4 to 5 bars doing this. The Ev project is recommending charging closer to the time you commute, so charging even more than from 80-100% is presumably better.

I'd be curious if this helps with extreme cold if someone is willing to try it.

Ted -

What are your recharging times like in the current cold weather?

GaslessInSeattle said:

The Ev project is recommending charging closer to the time you commute, so charging even more than from 80-100% is presumably better.

Click to expand...

When would the cells be balanced if all charges ended just before you started driving?

Ted said:

Do you happen to know how the on board computer estimates range and how temperature would affect it? While not terribly accurate in the best of times, at least in my experience, after a cold soak it was ridiculously off the mark. I'm wondering if the car is attempting to protect itself by limiting the discharge of the battery in cold temperatures.

Click to expand...

I don't use the onboard GuessOmeter just for those reasons.

Have you had the power limited in the cold ? I've only seen the regen limited by the cold. Your data would be awesome at that temp.

TonyWilliams said:

GaslessInSeattle said:

The Ev project is recommending charging closer to the time you commute, so charging even more than from 80-100% is presumably better.

Click to expand...

When would the cells be balanced if all charges ended just before you started driving?

Click to expand...

I occasionally leave the car plugged in at 100% for half a day or so about once or twice a month. it just happens that I charge to 100% and plans change so it just works out.

TonyWilliams said:

GaslessInSeattle said:

The Ev project is recommending charging closer to the time you commute, so charging even more than from 80-100% is presumably better.

Click to expand...

When would the cells be balanced if all charges ended just before you started driving?

Click to expand...

This was the subject of a request to Nissan Engineering for more information. We asked if it would be recommended to charge to 100% during the coldest part of the winter with the purpose of creating more internal heat in the battery and reducing the internal resistance, thus, reducing losses during discharge, and how that would affect the longevity of the battery compared to charging to 80%. Part of the hypothesis was that as heat is the main damaging factor for battery degradation, hence, the recommendation of charging to 80%, but given it is winter, I would assume that the damage caused by the heat would be reduced.

The answer was that, internally, the cells would experience similar levels of heat during a 100% charge regardless of the weather (debatable but somewhat believable as the pack is insulated and there is a battery heater), therefore, no real advantage would exist.

A commonly-heard suggestion is to time your charge to finish about 30 minutes before your expected departure to take advantage of the internal heat in the cells.

I'm now wondering if the electronics and motor are the ones affected the most by the cold weather, not the battery...

Interesting. hmm, well, I have found that the battery seems surprisingly resilient to cold and it's much more the climate control that eats the range. If I preheat so much that I don't need the climate control for my driving, the MPkW's stays in the 4's. I've been seeing that down into the upper/mid 20's (as cold as it's gotten here so far). I really don't know whether it's the prewarming that is keeping the MPkW's up or simply not using the Climate control at all or a combo. In any case, the 1% loss of range for every 2 degrees F does not seem to hold for me in this climate with the habits I have been applying, it's much less... I can still get 75-80 miles out of a charge. Since we can't measure the actual temp of the battery, we are guessing as to the effect of the cold on it for the most part... we don't even know how long it can retain residual heat from charging or use. Not being able to tell the actual battery temp is frustrating, since it makes it hard to determine exactly how close we are to an optimal temperature, we don't have a good target to shoot for. I've been shooting for 5 bars on the battery temp before driving and that seems to be good, but I also haven't done much driving with it at 4 bars or below, so I don't have much of a sense of when the big drop is, and certainly there is a drop at some point.

amtoro said:

TonyWilliams said:

GaslessInSeattle said:

The Ev project is recommending charging closer to the time you commute, so charging even more than from 80-100% is presumably better.

Click to expand...

When would the cells be balanced if all charges ended just before you started driving?

Click to expand...

This was the subject of a request to Nissan Engineering for more information. We asked if it would be recommended to charge to 100% during the coldest part of the winter with the purpose of creating more internal heat in the battery and reducing the internal resistance, thus, reducing losses during discharge, and how that would affect the longevity of the battery compared to charging to 80%. Part of the hypothesis was that as heat is the main damaging factor for battery degradation, hence, the recommendation of charging to 80%, but given it is winter, I would assume that the damage caused by the heat would be reduced.

The answer was that, internally, the cells would experience similar levels of heat during a 100% charge regardless of the weather (debatable but somewhat believable as the pack is insulated and there is a battery heater), therefore, no real advantage would exist.

A commonly-heard suggestion is to time your charge to finish about 30 minutes before your expected departure to take advantage of the internal heat in the cells.

I'm now wondering if the electronics and motor are the ones affected the most by the cold weather, not the battery...

Click to expand...

Regarding battery temperature, it would be good to know what it is. I have been driving with no bars showing on the battery temperature readout, and no more than 2 at any time this week.

that's hard core! I think I have temperature envy, I'd really like to experience that kind of cold and see if there is a way to maintain the range in it. Well, I say that now anyway.

Ted said:

Regarding battery temperature, it would be good to know what it is. I have been driving with no bars showing on the battery temperature readout, and no more than 2 at any time this week.

Click to expand...

GaslessInSeattle said:

Interesting. hmm, well, I have found that the battery seems surprisingly resilient to cold and it's much more the climate control that eats the range. If I preheat so much that I don't need the climate control for my driving, the MPkW's stays in the 4's. I've been seeing that down into the upper/mid 20's (as cold as it's gotten here so far). I really don't know whether it's the prewarming that is keeping the MPkW's up or simply not using the Climate control at all or a combo. In any case, the 1% loss of range for every 2 degrees F does not seem to hold for me in this climate with the habits I have been applying, it's much less... I can still get 75-80 miles out of a charge.

Click to expand...

Edited to reflect new formula for temperature correction.

Are you actually driving 75-80 miles, or getting that off the GOM ?

The 1% loss per 4F/2C below 70F/20C rule-of-thumb is for battery capacity, not reduction in miles/kWh. Your heater will reduce miles/kWh, not the battery's capacity.

Range is simply miles/kWh multiplied by battery kWh available.

Whether you think so or not, the non-temperature controlled battery will change its capacity with temperature changes. If you're getting 4m/kWh at a 20F battery temperature, your range is reduced by 70F-20F=50F temperature delta, so 50/4=12.5% reduction of the battery's capacity from 21kWh to 18.38kWh. In metric, 20C-(-7C)=27C temp delta, so 27/2=13.5% reduction in capacity.

I suspect that you're not actually experiencing that reduction if your car is protected from the elements to not allow your battery to reach ambient.

mark13 said:

I normally can do 2X60 mile runs on one full charge..One day I left the house with 65 miles left of charge,doing the summer that would be a no problem drive on my 60 mile commute,doing the winter its impossible to drive round trip on a 60 mile charge..

Click to expand...

Unrelated to the drop in range - instead of going from 100% to near empty for 2 days, why not just charge to 80% daily? More frequenty partial charges should be easier on the battery.

I'm talking 75-80 easily, mostly highway miles, before LB warning.

My car is kept in a non-insulated garage with a rather drafty door, darn close to ambient. In another thread you mention the charging process should add an insignificant amount of heat to the battery. Either my approach to charging/prewarming is adding significant heat to the battery, or the battery is remarkably resilient to cold. I'm not sure which, the important thing is that I'm getting the miles, remarkably close to the summer, by driving the same loop in as close to an identical way as I can muster over a wide range in temperatures since early fall. I will work on getting you KW readings from the blink, but for some reason, the charger comes on and off periodically, on it's own, it's like it tries to balance the cells even after an 80% charge. it's common to get up in the morning and have it show zero KW's for the last charge and I only charge to 80% at night. If a QC would be more accurate, I can run it down to VLBW the next time I drive to Olympia and see what it takes.

My goal has been to figure out how to get the most out of the car, as designed, using the tools it came with and so far, I'm pretty pleased with how it functions in this climate. A few changes to climate control, and adding the CWP would be very nice.

TonyWilliams said:

GaslessInSeattle said:

Interesting. hmm, well, I have found that the battery seems surprisingly resilient to cold and it's much more the climate control that eats the range. If I preheat so much that I don't need the climate control for my driving, the MPkW's stays in the 4's. I've been seeing that down into the upper/mid 20's (as cold as it's gotten here so far). I really don't know whether it's the prewarming that is keeping the MPkW's up or simply not using the Climate control at all or a combo. In any case, the 1% loss of range for every 2 degrees F does not seem to hold for me in this climate with the habits I have been applying, it's much less... I can still get 75-80 miles out of a charge.

Click to expand...

Are you actually driving 75-80 miles, or getting that off the GOM ?

The 1% per 2F rule-of-thumb is for battery capacity, not reduction in miles/kWh. Your heater will reduce miles/kWh, not the battery's capacity.

Range is simply miles/kWh multiplied by battery kWh available.

Whether you think so or not, the non-temperature controlled battery will change its capacity with temperature changes. If you're getting 4m/kWh at a 20F battery temperature, your range is reduced by 17%-25% due to reduction of the battery's capacity to 15.7kWh - 17.4kWh.

I suspect that you're not actually experiencing that reduction if your car is protected from the elements to not allow your battery to reach ambient.

Click to expand...

All interesting discussion. I think it would be good to point out though that we are all dealing with fundamentally different conditions. At Seattle temperatures I can believe tht the range isn't much affected, although i would think there would be some loss. I have experienced similar performance here in the fall and when cold temperatures were around freezing overnight and rising to 5 degrees celsius or so during othe day. This past week my drafty, unheated garage has been in the -20 degrees Celsius range and the temperature outside the door in the minus -30's. This has changed virtually everything when it co me to energy use and range.

The Leaf is still working though and hasn't left me stuck anywhere.

GaslessInSeattle said:

I'm talking 75-80 easily, mostly highway miles, before VLB warning.

My car is kept in a non-insulated garage with a rather drafty door, darn close to ambient. In another thread you mention the charging process should add an insignificant amount of heat to the battery. Either my approach to charging/prewarming is adding significant heat to the battery, or the battery is remarkably resilient to cold. I'm not sure which, the important thing is that I'm getting the miles, remarkably close to the summer, by driving the same loop in as close to an identical way as I can muster over a wide range in temperatures since early fall. I will work on getting you KW readings from the blink, but for some reason, the charger comes on and off periodically, on it's own, it's like it tries to balance the cells even after an 80% charge. it's common to get up in the morning and have it show zero KW's for the last charge and I only charge to 80% at night. If a QC would be more accurate, I can run it down to VLBW the next time I drive to Olympia and see what it takes.

My goal has been to figure out how to get the most out of the car, as designed, using the tools it came with and so far, I'm pretty pleased with how it functions in this climate. A few changes to climate control, and adding the CWP would be very nice.

TonyWilliams said:

GaslessInSeattle said:

Interesting. hmm, well, I have found that the battery seems surprisingly resilient to cold and it's much more the climate control that eats the range. If I preheat so much that I don't need the climate control for my driving, the MPkW's stays in the 4's. I've been seeing that down into the upper/mid 20's (as cold as it's gotten here so far). I really don't know whether it's the prewarming that is keeping the MPkW's up or simply not using the Climate control at all or a combo. In any case, the 1% loss of range for every 2 degrees F does not seem to hold for me in this climate with the habits I have been applying, it's much less... I can still get 75-80 miles out of a charge.

Click to expand...

Are you actually driving 75-80 miles, or getting that off the GOM ?

The 1% per 2F rule-of-thumb is for battery capacity, not reduction in miles/kWh. Your heater will reduce miles/kWh, not the battery's capacity.

Range is simply miles/kWh multiplied by battery kWh available.

Whether you think so or not, the non-temperature controlled battery will change its capacity with temperature changes. If you're getting 4m/kWh at a 20F battery temperature, your range is reduced by 17%-25% due to reduction of the battery's capacity to 15.7kWh - 17.4kWh.

I suspect that you're not actually experiencing that reduction if your car is protected from the elements to not allow your battery to reach ambient.

Click to expand...

Click to expand...

have you tried charging to 80% the night before and then charging to 100% in the morning while prewarming the cabin for a substantial amount of time, say 45 minutes to an hour? this is working well here, but I have no idea at what point doing this becomes less effective. also, do you have the CWP?

Ted said:

All interesting discussion. I think it would be good to point out though that we are all dealing with fundamentally different conditions. At Seattle temperatures I can believe tht the range isn't much affected, although i would think there would be some loss. I have experienced similar performance here in the fall and when cold temperatures were around freezing overnight and rising to 5 degrees celsius or so during othe day. This past week my drafty, unheated garage has been in the -20 degrees Celsius range and the temperature outside the door in the minus -30's. This has changed virtually everything when it co me to energy use and range.

The Leaf is still working though and hasn't left me stuck anywhere.

Click to expand...