Charging below freezing

[QueenBee]

Phil,

When you say "zero" are you saying "zero F" or "zero C"?

Zero C or 32 F.

-Phil

Why do you think the LEAF's battery heater doesn't turn on until much much colder?

 

[JPWhite]

Phil,

When you say "zero" are you saying "zero F" or "zero C"?

Zero C or 32 F.

-Phil

Why do you think the LEAF's battery heater doesn't turn on until much much colder?

It's not clear to me if the cold climate heater is triggered by battery temp or ambient temp. If it is triggered by ambient temp, Nissan may have determined this is a good time to turn on the blanket?

 

[abasile]

Our LEAF is always parked outside, and even with nighttime temperatures in the teens and 20s (F), I've never seen lower than four battery temperature bars. For most of the country it doesn't seem that "charging below freezing" could be much of an issue. If it's anything significant to worry about, then we'll eventually see reports from some of the many LEAF owners in Norway who routinely see very deep cold. Somehow I doubt that the level of degradation will be anywhere near that experienced by LEAF owners in extremely hot climates. No matter what we do, our batteries will degrade - it's just a matter of degree.

 

[Ingineer]

It's not clear to me if the cold climate heater is triggered by battery temp or ambient temp. If it is triggered by ambient temp, Nissan may have determined this is a good time to turn on the blanket?

-Phil

 

[garygid]

First and last lines: "temperature... in the battery pack"?

6th line: "temperature sensor installed to the battery pack".

So, most likely the 4 existing temperature sensors that are inside the battery pack.

 

[DaveEV]

Cliff notes: When the pack reaches -20C (-4F) the heater will turn on until the pack reaches -10C (14F), unless the SOC of the battery is very low.

So it's probably not a good idea to drain the battery if you expect to expose the car to less than -4F temps for some time without plugging in. If you plug in, the LBC will heat the battery as needed.

And unless you're seeing zero or 1 temperature bar, it's unlikely that the battery heater will be or has been activated.

 

[JPWhite]

I suppose the answer to my original question if Nissan have done anything to mitigate lithium plating while charging in freezing conditions, I suppose the answer is no. At least not in moderate freezing conditions, the blanket only triggers when the battery gets very cold.

 

[DaveinOlyWA]

turns on at -20, turns off at -10. well, sounds like

* us "2011'ers" have little to worry about until the pack gets to -10. if you have done any charging in past say X hours (X is anyone's guess and would assume it depends on the level of charge) you will be fine as there is some delay in temperature drop between pack and ambient.

* Nissan missed the boat on the cold weather effects like the hot weather effects and the North will be in the same boat as the South expect that the North will have the Aussies for company since Australia should start reporting loss of CB's here in a few weeks...

 

[DaveEV]

I suppose the answer to my original question if Nissan have done anything to mitigate lithium plating while charging in freezing conditions, I suppose the answer is no. At least not in moderate freezing conditions, the blanket only triggers when the battery gets very cold.

Besides heating, the LBC limits charge rate to mitigate lithium plating while charging in freezing conditions.

 

[jkirkebo]

Well, here's one report from Norway

My Leaf is now a little over 1 year old, 12000 miles and no sign of any degradation. Gids after a full charge is usually 279 and always 231 at 80%.

Last winter I was down to a single temperature bar more than once. I once tried charging from 80% to 100% when at one temp. bar and that didn't work out well. The SOC-meter showed only ~500 watts going into the pack so charge rate was way down. I aborted the charging and started driving instead, which quickly brought the pack up to 3-4 bars. No problems with charging thereafter.

So I do not think the cold is a problem for pack longevity, but it might impact charging if it gets cold enough. My advice is then to charge to 80% right after driving, when the pack is warmer. Do not let the car sit in the cold for long (a day or more) with a depleted battery as charging it up later might take forever.

 

[philipscoggins]

Thanks, jkirkebo

I've got no worries now. You definitely have colder weather to deal with than I do!

Philip

 

[DaveinOlyWA]

Well, here's one report from Norway

My Leaf is now a little over 1 year old, 12000 miles and no sign of any degradation. Gids after a full charge is usually 279 and always 231 at 80%.

Last winter I was down to a single temperature bar more than once. I once tried charging from 80% to 100% when at one temp. bar and that didn't work out well. The SOC-meter showed only ~500 watts going into the pack so charge rate was way down. I aborted the charging and started driving instead, which quickly brought the pack up to 3-4 bars. No problems with charging thereafter.

So I do not think the cold is a problem for pack longevity, but it might impact charging if it gets cold enough. My advice is then to charge to 80% right after driving, when the pack is warmer. Do not let the car sit in the cold for long (a day or more) with a depleted battery as charging it up later might take forever.

Great Info. are you on the Plug in America Survey. it would be great if you could submit your info and update it every 3-4 months.

http://www.mynissanleaf.com/viewtopic.php?f=27&t=10494" onclick="window.open(this.href);return false;

now you dont specify and you are right on the border but do you have 2011 or 12?

 

[taztaz]

That's just great. Now I have to worry about permanent battery reduction issues in the cold. It was 8 degrees F yesterday morning here. Maybe I need to charge at 120 this winter overnight instead of 240 to prevent permanent battery degradation, per the Battery U link from the previous poster. I have the cold weather package, and it the battery warmer should have kicked on at 14 degrees F, but our garage probably did not get that cold. How would I know that the battery warmer is on? Are there any icons on the dash or carwings (yeah, right ), or additional load on the charging circuit? I will keep an eye on it tonight--It is supposed to be cold again.

You can be quite calm.. They designed the battery heater to start heating the battery at -20 C and stop heating at -10 C .. I guess the battery is designed to be able to take charge at those temps.. And also the battery heats up when beeing charged.. The heater turns off at 14F (-10c) not on...

Here is a text from battery university:

Some Li-ion cells developed for power tool and EV applications can be charged at temperatures down to –10°C (14°F) at a reduced rate. To charge at a higher rate, Li-ion systems for automotive propulsion systems require a heating blanket. Some hybrid cars circulate warm cabin air through the batteries to raise the battery temperature, while high-performance electric cars heat and cool the battery with a liquid agent.

 

[willingp]

Seems like if there was battery damage from cold, the Chicago people would be shouting by now.

Philip

Judging by Phil's response, it seems prudent to plug-in and charge directly after stopping the vehicle when the temp is below freezing outside.

My routine in the summer is to leave the car at least 30 minutes before plugging in after getting home. In the winter I won't wait.

Here is my $0.02 shout from a climate colder than Chicago:
I have 2012 model, upstate NY, 1000' elevation. I have to chuckle when I read about 32F as being "cold". Cold here is below 0F, which frequently happens in winter. I do not have a heated garage, but have had no problems with 2012 model in the cold:
--If I charge as soon as I get home, and it's below 0F the next morning, battery heater keeps it at 2 bars
--If I set timer to charge at 2am, I have 3 or 4 bars in the morning when it's below 0F
--as noted by others, regenerative braking does not work when battery is cold, like two bars
--using the cabin heater to keep it toasty warm, like 65F, uses a humongous amount of battery: WITH cabin heater, my commute takes 14KWH of charging, compared to 9 or 10 in warm weather. I don't use cabin heater any more.

My settings for using Leaf in the frozen north:
--I HAVE NOT FOUND THE NEED TO USE THE CABIN HEATER AT ALL, EVEN BELOW 0F.
--I pre-heat the car while plugged in, for 5-10 minutes.
--I use the front seat and steering wheel heater (I no longer need gloves driving to work at sub zero temperatures).
--I set the front defrost on, then turn off AC, then set to minimum fan and minimum temp (60F)
--during my 16 mile commute, the energy monitor screen shows that this defrost setting plus the seat and steering heater uses an average of about 0.5 to 0.75 KW.
--At below 0F, recharging after my commute takes 10-11 KWH instead of 9-10 KWH in warmer weather, using this setting; and window never fogs or ices up (not at sub 0F, nor even when raining and 33F).
--and, no, I am not particularly cold hardy; my regular heavy winter coat plus the above keeps me quite comfortable, at least for my 35min trip.

Paul

 

[DaveinOlyWA]

Thanks for the detailed explanation. Do you find your comfort level the same on your afternoon commute home?
The reason i ask is that i don't use heat mostly because of range and mild weather but feel much warmer in the morning fitter to car in warmer garage and me fresh out if the shower. I don't preheat but then again, the car was 51° this morning and OAT was 43...so spring like weather for you guys

 

[Den]

--as noted by others, regenerative braking does not work when battery is cold, like two bars

Not true! It doesn't work (or works badly at max. 1-5kW rate) only for couple of first kilometers driven. Then it works better and better with every km driven (as battery warms up, even temperature bars doesn't change). You can monitor it by power-circles (at negative side, if it is double-circle it is working, if single then not) or by energy monitor.

--during my 16 mile commute, the energy monitor screen shows that this defrost setting plus the seat and steering heater uses an average of about 0.5 to 0.75 KW.

Energy monitor doesn't display consumption of seat and steering wheel heaters at all. So I wonder how you can know it from energy monitor!? :shock:

 

[JPWhite]

--during my 16 mile commute, the energy monitor screen shows that this defrost setting plus the seat and steering heater uses an average of about 0.5 to 0.75 KW.

Energy monitor doesn't display consumption of seat and steering wheel heaters at all. So I wonder how you can know it from energy monitor!? :shock:

I think all he was saying is with those three things turned on, the power consumption is .5 to .75. If the seat and steering wheel work off the 12v battery then the defrost is the consumer of all of the .5 or .75 kWh which is pretty good. I think the tip is great!!

 

[GetOffYourGas]

Here is my $0.02 shout from a climate colder than Chicago:
I have 2012 model, upstate NY, 1000' elevation. I have to chuckle when I read about 32F as being "cold". Cold here is below 0F, which frequently happens in winter. I do not have a heated garage, but have had no problems with 2012 model in the cold:
--If I charge as soon as I get home, and it's below 0F the next morning, battery heater keeps it at 2 bars
--If I set timer to charge at 2am, I have 3 or 4 bars in the morning when it's below 0F
--as noted by others, regenerative braking does not work when battery is cold, like two bars
--using the cabin heater to keep it toasty warm, like 65F, uses a humongous amount of battery: WITH cabin heater, my commute takes 14KWH of charging, compared to 9 or 10 in warm weather. I don't use cabin heater any more.

My settings for using Leaf in the frozen north:
--I HAVE NOT FOUND THE NEED TO USE THE CABIN HEATER AT ALL, EVEN BELOW 0F.
--I pre-heat the car while plugged in, for 5-10 minutes.
--I use the front seat and steering wheel heater (I no longer need gloves driving to work at sub zero temperatures).
--I set the front defrost on, then turn off AC, then set to minimum fan and minimum temp (60F)
--during my 16 mile commute, the energy monitor screen shows that this defrost setting plus the seat and steering heater uses an average of about 0.5 to 0.75 KW.
--At below 0F, recharging after my commute takes 10-11 KWH instead of 9-10 KWH in warmer weather, using this setting; and window never fogs or ices up (not at sub 0F, nor even when raining and 33F).
--and, no, I am not particularly cold hardy; my regular heavy winter coat plus the above keeps me quite comfortable, at least for my 35min trip.

Paul

First, welcome to the forum! What part of upstate do you live in?

I'm a little surprised at your claim that setting the defrost to 60F draws less than 1kW. I have done this, and it always settles to about 1.5-2kW (defrost on, AC off, min fan, min temp). It's especially frustrating because it seems to heat the fluid but not the air blown into the cabin.

 

[dgpcolorado]

--as noted by others, regenerative braking does not work when battery is cold, like two bars

Not true! It doesn't work (or works badly at max. 1-5kW rate) only for couple of first kilometers driven. Then it works better and better with every km driven (as battery warms up, even temperature bars doesn't change). You can monitor it by power-circles (at negative side, if it is double-circle it is working, if single then not) or by energy monitor...

Yes, the battery warms up quickly when driven and the regen comes back, assuming the charge isn't in the 90-100% range.

As an experiment, I did a 120 V trickle charge overnight, with a morning end time set at 80%, with the battery temp at four bars after a long hard drive up steep mountain passes. The morning temp was -8ºF (-22ºC) and I was at two temp bars at 8 AM and one temp bar at 9 AM after 40 minutes of preheating. So the battery didn't get to ambient temperature overnight while trickle charging but it was still falling in temperature by the morning. After less than three miles it was back to two temp bars and hit three temp bars after ten miles and 1700 feet of climbing. Trickle charging overnight in the cold did seem to work fine.

Charging at an EV friendly motel in Silverton, Colorado, elevation 9300 feet.

 

[JPWhite]

Charging at an EV friendly motel in Silverton, Colorado, elevation 9300 feet.

Nice pic

How does the LEAF handle in the snow compared to other front wheel drive vehicles? Is the traction control an asset or a hindrance?