One more winter range post- 33*, 80% to 0 bars: 32.8 miles

[LEAFfan]

I just opened a file with Nissan and they will try to research it with the engineers and keep the information for future reference.
The question is:
The recommended charging regime for maximum battery life is 80% all the time, mainly due to the heat produced during the last 20% of charging. Timing the charging session to end 60 to 30 minutes before departure time would allow to have a warmer battery at the start of the morning commute, but would it help the range, or still be detrimental to the battery to charge to 100% during winter months? Let's see what they can answer

What affects your range more than a cold battery is the denser air that comes with colder temps. I get about 1m/kW h less when it's in the 50's (F) vs. 60s to low 70s. Most of the cell balancing is is believed to be done at 100% so it doesn't hurt once in a while to charge to 100%. In fact, in the cooler temps, it wouldn't hurt to charge your pack to 100% every day. Even when I QC, my temp gauge only goes from five to six. Also, I hit 100% on my SOC gauge for the first time which is from the QCing. Before QCing, it would only go to 95% using L2 (94.6). Before QCing, doing an L2 80% charge, it would only go to 76.8. After using QCing, it hits 82%! So, what affects your m/kW h isn't the cold battery, but the denser air. This is what a couple people on here have said, and I verified it with the QC techs. They are continually testing their LEAFs with the QCs and have discovered many things we didn't know.

 

[LEAFfan]

The hope is that the battery is cool enough that charging to 100% won't be detrimental. Any thoughts?

You don't have to wait to begin charging your pack after driving, UNLESS the temp gauge is in the red. Nissan reps have already verified this. What is in the manual is misleading. The Japanese at times have trouble putting their language into clear English.

 

[dgpcolorado]

The morning I had one bar the car had been sitting for three days and the temperature was -16C (3F). <snip>

Shortly after drivng away I got the second bar then the thord some time later and the fourth a little after an hour of driving. The fifth bar I got after fast charging for 70(!) minutes.

This is very useful cold-weather data; thank you! I am pleased to see confirmation that driving with a cold pack can raise its temperature significantly. We need more Quick Chargers here in the States!

+1

Thank you very much jkirkebo! Please keep your cold weather reports coming.

 

[TonyWilliams]

What affects your range more than a cold battery is the denser air that comes with colder temps.

I don't think this is even close to correct. It takes a pretty big temperature change to equate to a couple thousand feet elevation difference, and with about a 1.5% difference per thousand feet, that's not even close to what those temps can do to the battery's capacity.

 

[ebill3]

The recommended charging regime for maximum battery life is 80% all the time, mainly due to the heat produced during the las 20% of charging.

Are you sure of that? I don't think heat is the culprit - it is the high SOC that is detrimental to battery life. A 16 Amp L2 charge is really a quite gentle charge, and is not going to generate a significant amount of heat. The DC quick charge is quite another matter.

Bill

 

[TonyWilliams]

The recommended charging regime for maximum battery life is 80% all the time, mainly due to the heat produced during the las 20% of charging.

Are you sure of that? I don't think heat is the culprit - it is the high SOC that is detrimental to battery life. A 16 Amp L2 charge is really a quite gentle charge, and is not going to generate a significant amount of heat. The DC quick charge is quite another matter.

Bill

Even the DC charger ramps WAY down for that last 20% (as requested from the LEAF). The reason, it seems, for 80% is not letting the car sit with 100%.

 

[vegastar]

That's why I time the charge to stop at 100% at my time of departure in the morning. The car stays above 90% SOC for less than an hour/day. 80% of the day my car has a SOC below 60%.

 

[GaslessInSeattle]

I'm finding the cold is having almost no effect on the battery. I drove 73 miles today on almost 100% highway with 2 bars left. it was about 39 degrees out. the dash showed 4.5 MPkW, where as just a few weeks ago I was getting 3.3 MPkW, the only difference is that I now drive with the Climate control turned off now, in foot and defog mode after a decent prewarm. the vast majority of the difference people are reporting is due to climate control, not air density or anything else... at least that's what I'm seeing.

if you need the range, try this, it really works!

 

[TonyWilliams]

I'm finding the cold is having almost no effect on the battery.

I don't think that the cold weather will be reflected in the miles/kWh, except for additional power consumption (like the heater). But, it's pretty clear to me that the is a definite contraction in battery available capacity. Heck, it would be odd if there wasn't!

Was your battery temperature 39 degrees, or was your car sitting in a garage that was substantially warmer, and a battery that just completed charging to warm it further?

 

[LEAFfan]

I'm finding the cold is having almost no effect on the battery.

I don't think that the cold weather will be reflected in the miles/kWh, except for additional power consumption (like the heater).

You are incorrect Tony. There are only a couple people on this forum that had it correct, and I can't remember who they were. The QC techs verified it for me. The colder air (much denser than warmer air) definitely affects the m/kW h. The colder battery affects its capacity, NOT the m/kW h. They have been testing LEAFs for quite some time. All three of them are in agreement with this. I too once thought that the colder battery was decreasing my m/kW h, but now I know that isn't true.

 

[Herm]

cold tires on a dry road have twice the drag of warm tires.. granted its not much with modern low-rolling resistance tires pumped up to 80psi but it adds up.. and its not dependent much on speed.

 

[edatoakrun]

I'm finding the cold is having almost no effect on the battery.

I don't think that the cold weather will be reflected in the miles/kWh, except for additional power consumption (like the heater).

You are incorrect Tony. There are only a couple people on this forum that had it correct, and I can't remember who they were. The QC techs verified it for me. The colder air (much denser than warmer air) definitely affects the m/kW h. The colder battery affects its capacity, NOT the m/kW h. They have been testing LEAFs for quite some time. All three of them are in agreement with this. I too once thought that the colder battery was decreasing my m/kW h, but now I know that isn't true.

I'm still seeing the about the same daily results I posted here (and just edited for clarity, BTW) where a 40 degree temperature drop reduced both m/kWh, and available battery capacity:

"On 11/8 I attempted to replicate the route and conditions of an earlier trip, which I had kept careful notes of, to try to see what sort of range reduction is caused by reduced m/kWh due to lower temperatures, and what proportion of this reduction is due to reduced battery capacity. I did this on a dry day with windows up, without using the heater or windshield wipers. I believe that I got about 5% reduction in battery capacity, and a slightly larger decrease in driving efficiency (m/kWh) resulting in a total range reduction of over 10%...."

http://www.mynissanleaf.com/viewtopic.php?f=31&t=6701&start=60" onclick="window.open(this.href);return false;

 

[abasile]

The colder battery affects its capacity, NOT the m/kW h.

It is my understanding that the colder the pack, the higher the internal resistance. Higher internal resistance translates to lower overall miles/kWh relative to the energy stored in the battery, and thankfully, additional battery heating as jkirkebo clearly observed. Whether the reported miles/kWh fully accounts for this loss is another question, though.

 

[GaslessInSeattle]

Once I figured out how to manage the air circulation with climate control turned off, zero energy, my range that had plummeted to something abysmal like 50 miles a charge, bounced back to summer time, about 80-85 miles. the guesometer is even starting with the numbers I was seeing in the summer, showed 101 estimated miles on an 80% charge the other morning after charging overnight in an unheated/uninsulated garage. Some folks are doing even better, but keep in mind we are a 4 person family with 2 adults and 2 kids in the car much of the time and we live in a hilly area. I do expect that when it gets much colder we will see the effect of cold on the battery, but so far, the main culprit has turned out to be the climate control. We are not seeing the 1% loss for every two degrees below 70 that has been circulated. preheating enough to warm the car itself, not just the air has made this doable...again, cc off, mode set to foot defog and the cabin stays nice and toasty for a good 30-45 minutes of high speed driving and windows stay crystal clear.

I'm finding the cold is having almost no effect on the battery.

I don't think that the cold weather will be reflected in the miles/kWh, except for additional power consumption (like the heater). But, it's pretty clear to me that the is a definite contraction in battery available capacity. Heck, it would be odd if there wasn't!

Was your battery temperature 39 degrees, or was your car sitting in a garage that was substantially warmer, and a battery that just completed charging to warm it further?

 

[DaveinOlyWA]

The colder battery affects its capacity, NOT the m/kW h.

It is my understanding that the colder the pack, the higher the internal resistance. Higher internal resistance translates to lower overall miles/kWh relative to the energy stored in the battery, and thankfully, additional battery heating as jkirkebo clearly observed. Whether the reported miles/kWh fully accounts for this loss is another question, though.

your miles/kw will be impacted by denser air, climate control, etc.

on my winter range test, i got 5.3 miles/kw which is great compared to my average winter driving where i am averaging about 4-4.4 miles. but that same driving would have me in the 6½ mile range were it summer and my test had less than 5 minutes of run time on climate control so not really a factor.

 

[DaveinOlyWA]

Ok, SO just got home from Work. Centrailia trip. 62.6 miles on odometer. temps in high 30's. she got home on _ _ _ 3.6 miles per K that is probably around 17.25 kw used and probably only had 2-3 miles before turtle. she called when GOM hit 25 miles and she was still 27 miles from home. on the freeway she states she dropped down to 50-55 mph (she might have embellished a bit in her bid to not take the Leaf until next summer. i say that because she got home 20 minutes later than normal but did do a quick stop on way home.)

she did admit to going to work this morning (running late as usual) at 65 mph,

either way, seems like i am getting less and less capacity available. current temp was 32º

 

[amtoro]

I just opened a file with Nissan and they will try to research it with the engineers and keep the information for future reference.

The question is:
The recommended charging regime for maximum battery life is 80% all the time, mainly due to the heat produced during the las 20% of charging. Timing the charging session to end 60 to 30 minutes before departure time would allow to have a warmer battery at the start of the morning commute, but would it help the range, or still be detrimental to the battery to charge to 100% during winter months?

Let's see what they can answer

The official answer from Engineering at Nissan is that as the cells in the battery will reach the same temperature in summer or winter when charging to 100% regardless of the ambient temperature, therefore, the degradation will be the same. It is still recommended to charge to 80% for longer battery life.

It seems that the recommendation would be to use the end timer to finish charging 30 to 60 minutes before starting the drive, this will have the advantage of having a warm battery with less internal resistance that a cold battery (and less losses due to it) and giving the battery a prudent time to equalize before discharging.

 

[edatoakrun]

I just opened a file with Nissan and they will try to research it with the engineers and keep the information for future reference.

The question is:
The recommended charging regime for maximum battery life is 80% all the time, mainly due to the heat produced during the las 20% of charging. Timing the charging session to end 60 to 30 minutes before departure time would allow to have a warmer battery at the start of the morning commute, but would it help the range, or still be detrimental to the battery to charge to 100% during winter months?

Let's see what they can answer

The official answer from Engineering at Nissan is that as the cells in the battery will reach the same temperature in summer or winter when charging to 100% regardless of the ambient temperature...

Huh???

 

[abasile]

The official answer from Engineering at Nissan is that as the cells in the battery will reach the same temperature in summer or winter when charging to 100% regardless of the ambient temperature, therefore, the degradation will be the same.

That can't be. I don't for a second believe that, upon completion of a 100% charge, the battery cells will end up at the same temperature whether the ambient temperature is 20°F or 110°F. Charging to 100% does produce some additional heat, but not that much. My guess is that, somewhere along the line, Engineering's response got garbled.

 

[GRA]

<snip>

Some folks are doing even better, but keep in mind we are a 4 person family with 2 adults and 2 kids in the car much of the time and we live in a hilly area.

George, have any of you, especially your kids, noticed or been bothered by the high-frequency whine between about 45-55 reported by CR and Motor Trend? The Motor Trend writer said he and his family all had a high-frequency ringing in their ears after a long trip, and the audio spectrograph photos in the magazine of all three cars (Prius/Volt/Leaf) clearly showed the noise bands he was referring to:

http://www.motortrend.com/roadtests/alternative/1108_2011_chevrolet_volt_vs_2011_nissan_leaf_vs_2011_toyota_prius_comparison/viewall.html" onclick="window.open(this.href);return false;

I didn't notice a problem when I test drove the car but I have essentially zero hearing left above 2kHz, and didn't spend much time in the 45-55 speed range in any case.