Cold Weather Observations

It's 2 degrees outside today, and it would appear the Leaf really does not like the cold (I know that's no surprise here). A few things that I noticed:

1. Charging finished more than 2 hours before my end time this morning. I wonder if the battery was not able to accept a full charge.
2. During the freezing rain yesterday I had to crank the defrost heat in order to keep the windshield from icing up. At the end of the day all the ICE cars in the parking lot were dry (the heat of the cars melted the ice), but my Leaf is still covered in ice today.
3. I burned 55% of my charge in just 23 miles. I think this is a combination of really bad m/kwh (about 2.7) and the battery not being able to fully charge in the cold.
4. I pumped my tire pressure up. When you guys say you keep the pressure at 42psi, is that after driving or before? I noticed my pressure started the drive at 39 and ended it at 42 (according to leafspy).
5. When I ran the heat this morning with the Leaf still plugged in the three charging lights never came on. Does the Leaf draw power when warming up if the charging cycle is complete? Should the lights have come on?

If Leaf gets full charge, the lights will turn off
Yes, good old ICE car melts the ice, yet my Leaf is also iced up Its second day with -15-18 Celsius and its range is also down too.

My battery was only 1bar this morning (my Leaf does not have battery heater for some reason, nor heated side mirrors) and it didnt like charge at all. But besides that, i dont see any problems with it in the cold. My leaf has seen -20 celsius and was hot inside, drove perfectly normal and had absolutely no problems with range

Tire pressure is set cold (before a drive) but in normal weather, not frigid. The car should charge normally at that temp.

bongo2 said:

It's 2 degrees outside today, and it would appear the Leaf really does not like the cold (I know that's no surprise here). A few things that I noticed:

1. Charging finished more than 2 hours before my end time this morning. I wonder if the battery was not able to accept a full charge.
2. During the freezing rain yesterday I had to crank the defrost heat in order to keep the windshield from icing up. At the end of the day all the ICE cars in the parking lot were dry (the heat of the cars melted the ice), but my Leaf is still covered in ice today.
3. I burned 55% of my charge in just 23 miles. I think this is a combination of really bad m/kwh (about 2.7) and the battery not being able to fully charge in the cold.
4. I pumped my tire pressure up. When you guys say you keep the pressure at 42psi, is that after driving or before? I noticed my pressure started the drive at 39 and ended it at 42 (according to leafspy).
5. When I ran the heat this morning with the Leaf still plugged in the three charging lights never came on. Does the Leaf draw power when warming up if the charging cycle is complete? Should the lights have come on?

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1. What was the SOC% of your battery when you left? and did you use preheat and if so what is the amps/volts of your EVSE?
2. Yes ICE vehicles literally have heat to burn, not so with a EV where heat is very precious and consumes a lot of range
3. Yes thats not unheard of for me either, especially if running full heat to keep windows clear. I'm also averaging only 2.7 miles/kwh but note that will greatly improve as weather warms up. I always say 40s make little difference in range, you start to see more in the 30s and 20s, it's quite noticeable in the teens and even worse in single digits, below zero(F) gets downright bad. Preheating really helps but really only with L2, L1 at cold temps is mostly worthless, also L1 charging in cold temps is even worse than warm temps, almost unbearable. I ran all summer just using L1 but along came our first MN winter and I was forced to go L2, much happier now
4. As LB said, yes measure tire pressures before you drive. I run the max of 44PSI in my Ecopias but note only really check them when it's in the 20s, I don't like doing it when it's colder(I do it with a gauge). If I were checking when temps were in the single digits I'd probably lower it by a couple pounds as I wouldn't them to get too high when the temp rises back to the 40s as there predicting for Friday
5. Power should come from your EVSE but note if it's only a L1 you WILL lose charge during preheat, and expect maybe 10%?? for a full 30 minute preheat. This is another reason to get a L2 EVSE and preferable one >16a. With more than 16a 240v you can not only not lose charge during preheat but actually gain charge. Note if you have a pre '13 Leaf or a Leaf with the 3.6kwh charger 16a is the maximum you'll get no matter how high your EVSE might go, for this reason I really prefer the 6.6kwh Leaf charger for cold weather use.
Even if all of the lights have gone off due to being charged I believe during preheat one of the lights should still flash, note with L1 it won't charge and preheat at the same time, you'll actually lose charge during preheat as all the EVSE power and more will be going to the heater and nothing will be leftover to go to the battery.

...also L1 charging in cold temps is even worse than warm temps, almost unbearable.

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I find the charge rate to be the same, so I assume you mean it's harder to drive on the same amount of L-1-derived charge in cold weather?

note with L1 it won't charge and preheat at the same time, you'll actually lose charge during preheat as all the EVSE power and more will be going to the heater and nothing will be leftover to go to the battery.

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This could be considered just semantics, but the car does charge while plugged in and preheating with L-1. The pack is charging, and is also being used to power the heater. It just loses more charge than it gains. The best way to preheat with L-1 is to do it for only 2-3 minutes. This uses only 2-3% charge but gets the cabin warm enough to matter. It also lets the wheel and seat get warm. Even a one minute preheat in frigid weather can make a real difference in comfort, at minimal range cost.

jjeff said:

1. What was the SOC% of your battery when you left? and did you use preheat and if so what is the amps/volts of your EVSE?
5. Power should come from your EVSE but note if it's only a L1 you WILL lose charge during preheat, and expect maybe 10%?? for a full 30 minute preheat...Even if all of the lights have gone off due to being charged I believe during preheat one of the lights should still flash.

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My EVSE is a 3.6KW (I don't have the 6KW charger on my car). I think the SOC was 98% when I left and I probably preheated it for only about 5 minutes before I left. It's odd that the lights didn't show any charging, but maybe I'd crossed wires with the delay timer or something.

jjeff, you recommend running down to turtle one or two times when you first get a leaf to balance out the cells, right? Do you think today is as good a day as any, or do you think doing it at this temperature is a stress on the battery?

LeftieBiker said:

...also L1 charging in cold temps is even worse than warm temps, almost unbearable.

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I find the charge rate to be the same, so I assume you mean it's harder to drive on the same amount of L-1-derived charge in cold weather?

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Correct, in cold weather you need more charge for a given use so the slowness of L1 becomes even more noticeable.

LeftieBiker said:

note with L1 it won't charge and preheat at the same time, you'll actually lose charge during preheat as all the EVSE power and more will be going to the heater and nothing will be leftover to go to the battery.

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This could be considered just semantics, but the car does charge while plugged in and preheating with L-1. The pack is charging, and is also being used to power the heater. It just loses more charge than it gains. The best way to preheat with L-1 is to do it for only 2-3 minutes. This uses only 2-3% charge but gets the cabin warm enough to matter. It also lets the wheel and seat get warm. Even a one minute preheat in frigid weather can make a real difference in comfort, at minimal range cost.

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Yes your correct, it does charge, just not enough to overcome the heater
While I agree with your morning warmup routine, it's very nice to get into a toasty warm car when the temps are cold, your routine just takes the chill out of the air which is better than nothing but with a toasty warm car I find running the heater for my rather short commute is mostly unnecessary, unless window fogging becomes an issue.

bongo2 said:

jjeff said:

1. What was the SOC% of your battery when you left? and did you use preheat and if so what is the amps/volts of your EVSE?
5. Power should come from your EVSE but note if it's only a L1 you WILL lose charge during preheat, and expect maybe 10%?? for a full 30 minute preheat...Even if all of the lights have gone off due to being charged I believe during preheat one of the lights should still flash.

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My EVSE is a 3.6KW (I don't have the 6KW charger on my car). I think the SOC was 98% when I left and I probably preheated it for only about 5 minutes before I left. It's odd that the lights didn't show any charging, but maybe I'd crossed wires with the delay timer or something.

jjeff, you recommend running down to turtle one or two times when you first get a leaf to balance out the cells, right? Do you think today is as good a day as any, or do you think doing it at this temperature is a stress on the battery?

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Everything sounds about right then, I wasn't sure if your S had the upgraded charger or not.
I preheat my Leaf in a couple ways, one is at home(with a 30a EVSE) where I have my charge timer set for about the time I leave for work, this results in the charge being done ~1hr before I leave due to the timer being somewhat pessimistic, better that way than done late I have my climate control timer set for 5 minutes after I leave, it starts 30 minutes prior so in this case my car has warmed up for 25 minutes and gives me 5 minutes in case I'm running late. Doing this I leave with a 100% charge and warm car. Doing the same thing on my '12SL(with the 3.6kw charger) I find the car not quite as warm and my charge ~10% less than I've set it for, due to the 3.6kw charger not being able to keep up with the pre-heater.
At work where I have a 16a 240v plug-in, I go out to my car a little before I leave, push the timer override button and turn the car ON(with my foot on the brake). I then exit the car and lock it with the outside lock button. I come back to my car a little later, unplug the car, restart the car and leave with a somewhat warm car down a few % charge.
Personally I wouldn't do the turtle discharge cycle in such cold temps, I'd wait for a moderate day like Friday?? where the temps are predicted to be in the 40s running the battery that low in the extreme cold might not be such a good idea, at least I wouldn't.

jjeff said:

running the battery that low in the extreme cold might not be such a good idea, at least I wouldn't.

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That's what I was thinking too. I'm itching to try it and see if it helps my battery, but I need patience.

jjeff, you recommend running down to turtle one or two times when you first get a leaf to balance out the cells, right?

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The Leaf's cells, like most if not all lithium packs, are top balanced, so balancing occurs as charging finishes, not as it starts. There is no reason, ever, to run a Leaf down to Turtle mode to balance it! It can be a good idea to run it down to the first or second Low Battery Warning, but that is to establish the car's range, and has nothing to do with balancing the pack.

For our winters in Colorado:

Gloves
Warm shoes
Heat seater for comfort
Outside air ventilation on a fan setting of 1-2 to keep the windows clear.

End of story, very minimal hit to fuel efficiency. People who live in more humid climates have a bigger chore.

LeftieBiker said:

There is no reason, ever, to run a Leaf down to Turtle mode to balance it! It can be a good idea to run it down to the first or second Low Battery Warning, but that is to establish the car's range, and has nothing to do with balancing the pack.

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Thanks for that perspective. What makes you think that there is no reason to ever run the battery down to turtle? You may be right, but there are a couple things that make me think you may be wrong: 1) some people have reported that running their Leaf to its full range a few times helps their battery, and 2) other batteries that I buy (for example the external battery on my phone) will often have a recommendation like "to maintain the full capacity fully discharge and charge this battery at least once every three months".

bongo2 said:

[ 1) some people have reported that running their Leaf to its full range a few times helps their battery.

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Remember that most (if not all) of these people have no way of gauging their battery's health other than taking the car's instrumentation at face value. Even those putting their LeafSpy results under a microscope are just looking at regurgitated data extracted from the car's systems. I could easily accept that the battery cell voltage measurements are probably fairly un-processed, but aren't all the other metrics just the outputs of somewhat mysterious algorithms? So there's the possibility that effects like "gee, if I cycle the battery from turtle to bursting, the 'health' metric rises" are coming more from the instrumentation than the battery itself?

bongo2 said:

LeftieBiker said:

There is no reason, ever, to run a Leaf down to Turtle mode to balance it! It can be a good idea to run it down to the first or second Low Battery Warning, but that is to establish the car's range, and has nothing to do with balancing the pack.

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Thanks for that perspective. What makes you think that there is no reason to ever run the battery down to turtle? You may be right, but there are a couple things that make me think you may be wrong: 1) some people have reported that running their Leaf to its full range a few times helps their battery, and 2) other batteries that I buy (for example the external battery on my phone) will often have a recommendation like "to maintain the full capacity fully discharge and charge this battery at least once every three months".

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Unless the phone uses a NiCad battery, that isn't likely to be true. If it is true, it's a quirk of the phone's battery management system, rather than a characteristic of the battery itself. Lithium cells are damaged by near-complete discharges, just like other battery types except NiCad. The damage is often minor, but it's not helping the battery. Lithium cells are happiest in the middle to the lower third of their charge range. They don't like being full, and don't like being empty.

Levenkay said:

bongo2 said:

[ 1) some people have reported that running their Leaf to its full range a few times helps their battery.

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So there's the possibility that effects like "gee, if I cycle the battery from turtle to bursting, the 'health' metric rises" are coming more from the instrumentation than the battery itself?

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I know when I did it to my '12SL it helped restore my SOC% display(using LeafDD). When I first got my used '12 it would only charge to a max of ~90% SOC and stop charging, the battery cell differential was also all over the place. After a couple full discharge/recharge cycles I was able to get my SOC up to 95% and the battery cell differential looked quite a bit better. Note 6 months after doing this it's back to stopping charge at ~92% but still better than before. I suppose I could do it again but I mainly I did it because I had no idea what the previous owners charging routine was, did he frequently top off? Leave at a high SOC? frequently run it down to VLBW? I just didn't know. I did know that in less than 30k miles they had to replace all tires(car had basically new aftermarket cheap tires) and battery was down 2 bars, so obviously they were a bit hard on the car. Now what I didn't check and would have been more important than just noting the SOC display would have been the Ahr of the battery, thats the true measure of the battery but I still didn't like the battery stopping charge at only 90%(and sometimes less) so for that reason alone I might suggest doing this at least once or twice on a older Leaf, for sure on one you've purchased used.
I've never done the balancing routine on my '13S I purchased new and it still charges to 100% SOC and it's battery cell differential looks pretty decent, of course I know how it's been driven and charged and it's also always been a Northern car, my '12 came from So. Cal, a real hotbed.

I think that if you had just fully charged-equalized the older Leaf a few times, you would have seen the same improvement. I guess it's possible that the BMS can benefit from running to VLBW or even Turtle and back, but not the battery pack itself.

LeftieBiker said:

I think that if you had just fully charged-equalized the older Leaf a few times, you would have seen the same improvement. I guess it's possible that the BMS can benefit from running to VLBW or even Turtle and back, but not the battery pack itself.

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Actually I had charged quite a few times to full and yet it would always stop at ~SOC 90%, something that I've read is somewhat common with a degraded battery. Your probably right, doing the cycling thing might just recalibrate the BMS and while I might not have gained any battery power I still like seeing the battery closer to 100% than 90% fully charged, just kind of psychological

It's pretty common in EVs for the BMS to wander off a bit. Since it's hard to reboot a leaf BMS (unless you're an unscrupulous mechanic with Consult II) then this might be what's happening: re-calibration. If so, then one brief trip to Turtle might be enough. It would be worth finding out if any point above Turtle Mode would also work.

It warmed up to 20F this morning and what a difference! m/kwh of 4.2 instead of 2.7 (probably helps that it's not covered in ice). It's a whole new car. To be fair my ICE vehicle doesn't love it when it's 0 either. . .

We had an early spring day yesterday into the 40s F so we took a nice 45 mile (each way) trip to a neighboring town we enjoy for the shopping, eating and walking about downtown. Overall about 5 miles/kWh despite 2000 ft elevation bump in the middle of each leg as we drove through the San Juan Mts of Colorado

Free recharging at the destination, so net we paid for 6 kWh of home charging. That works out to 54 cents today, but will be about 15 cents from next month when the PV is up and running.

15 cents of fuel costs to travel 90 miles. Pretty good :mrgreen: