# Re: [EVDL] [seva] The effects of cold weather on EVs



## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*

Thanks for your reply. I am surprised, however, that headlights would have
much of an effect. While the average incandescent headlight consumes 55
watts, the average LED (which is what the Leaf has) should consume about 14
watts, so less than a total of 30 watts for both headlights. Even if your
average speed is only 15 mph in traffic, that is only 2 wh/mile.

Now I always thought that the main load on the energy in cold weather was
heating the inside of the car, and so I assumed that electrically headed
seats and steering wheel would provide adequate comfort while dramatically
cutting the energy drain (say 50 watts/seat for 2 seats: even at 15 mph
that is less than 7 wh/mile drain). But I was told by someone who has
heated seats that this is not true, so I still don't know why the Leaf is
so affected by cold weather (although one person noted you have to defog
the windows and that might take some AC).

-- Larry Gales



> Jim Adcock <[email protected]> wrote:
> 
> > [Sorry for a late reply, but just back from winter break]
> >
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*



> On 26 Feb 2012 at 15:49, Cory Cross wrote:
> 
> > http://crispgreen.com/2010/10/new-nissan-leaf-gets-low-cost-led-headlights
> > /
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*

Well, I'm surprised at the statement that Halogen and LED headlights (which
the Leaf has, at least for low beams) have similar power needs. According
to this reference:

http://www.ehow.com/facts_5608302_halogen-vs_-led-light.html

LEDs are 75% more efficient than Halogens.

As far as measurements go, I don't have access to a Leaf, so I must reply
on the literature or statements by knowledgeable owners, but I still don't
have a feeling for the energy drain given that it does not appear to be the
battery (except at very low temps, and (at least if the Leaf can select
which seats to heat) the energy for heated seats does not seem large.

-- Larry




> Cory Cross <[email protected]> wrote:
> 
> > Well, let me correct the LED thing:
> >
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*



> On 26 Feb 2012 at 18:03, Larry Gales wrote:
> 
> > According to this reference:
> >
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*

I am most certainly not trying to spread false information. Here is the
situation:

(1) Nearly all reports I have read states that EVs suffer significant range
reductions
in cold weather: Consumer Reports puts the range of the Leaf at no
more than 65 miles
in cold weather, Nissan's own test indicate a range as low as 47 miles
in slow driving in the
cold, I have seen many reports of iMiev's having reduced range in the
cold.
(2) Those heaters that heat the whole interior of the car typically run as
high as 2-3 KW,
so 3 hours at 3 KW would consume more than 1/3 range of a Leaf
(3) On the other hand, seat warmers are about 50 watts/seat, so two heated
seats should
consume 20-30 times less energy in very cold weather
(4) My preliminary conclusion was that heated seats should provide
sufficient comfort in
cold weather with very little effect on the range
(5) So I was very surprised at the SEVA meeting when I was told that heated
seats did
NOT benefit the range.
If I misheard at the SEVA meeting, than i would be delighted to know that
heated seats solve the problem, so if someone remembers what was said
better than I did, please let me know.

-- Larry Gales





> Cory Cross <[email protected]> wrote:
> 
> > On 02/26/2012 06:03 PM, Larry Gales wrote:
> >
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*



> On 27 Feb 2012 at 23:39, Larry Gales wrote:
> 
> > It would be nice to find some means of defogging the windows without
> > heating up the entire inside of the car.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*

Rolls Royce's have had this for yonks, Renault and Citroen too (I believe) but not as long - others use a grid of extremely fine wires (only just visible to naked eye) - downside is it blocks radio signals so external antennae are required for all your satnavs, phones etc.

MW




> EVDL Administrator wrote:
> 
> > On 27 Feb 2012 at 23:39, Larry Gales wrote:
> >
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*

Lee,
So you could buy a second windshield, space it 3/8 of an inch into the car
and seal it op good with a port one side on the bottom, other side on the
top and run argon through it for a while, job done.

Interesting.


Sincerely,
Mark Grasser


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*



> Mark Grasser wrote:
> 
> > So you could buy a second windshield, space it 3/8 of an inch into the car
> > and seal it op good with a port one side on the bottom, other side on the
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*



> On 28 Feb 2012 at 11:07, Jukka J=E4rvinen wrote:
> 
> > Lithium cells do not lose capacity in cold.
> 
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*



> Mark Grasser wrote:
> >> So you could buy a second windshield, space it 3/8 of an inch...
> 
> Roger Stockton wrote:
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*

The "Frost Shields" were clear plastic (vinyl?) with a 1/2" wide rim all ar=
ound. It had a sticky surface protected by a sheet of paper. One lined up t=
he sheet in position and peeled off the paper. Pressing on the rim made it =
stick to the glass with a sealed chamber between the plastic and the window=
glass. The shields came in various sizes and did not interfere with vis=
ion day or night. We had those on side & rear windows. The windshield might=
frost up but these did not. They lasted for about three or four years befo=
re cracking or discolouring. I think autoparts stores still sell them aroun=
d here in the Canadian prairies 

Some of the old Bugs even put the frost shields even on the windshield

regards
hg

----- Original Message -----
From: Lee Hart <[email protected]>
Date: Tuesday, February 28, 2012 3:13 pm
Subject: Re: [EVDL] [seva] The effects of cold weather on EVs
To: Electric Vehicle Discussion List <[email protected]>



> > Mark Grasser wrote:
> > >> So you could buy a second windshield, space it 3/8 of an inch...
> > =
> 
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*

And the internal resistance goes up. Thus, cruising at 60 mph took 115A at
25F where it only took 100A to cruise the same speed at 75F. That is
because the internal resistance caused voltage droop and my voltage was now
at 130V instead of 140+V. The motor still wants 14 kW and doesn't care how
many amps it takes to get it.

Mike

> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of EVDL Administrator
> Sent: Tuesday, February 28, 2012 1:32 PM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] [seva] The effects of cold weather on EVs
> =



> > On 28 Feb 2012 at 11:07, Jukka J=E4rvinen wrote:
> > =
> 
> > > Lithium cells do not lose capacity in cold.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] [seva] The effects of cold weather on EVs*

It looks like no one directly answered your question, David. Unless it
is extremely cold and there is no insulation around the batteries they
will be over 0=B0C by the time you reach your destination if you are
driving the batteries nearly flat. I have observed two things with my
pack. A colder pack warms up more than a warmer pack for a given
energy expenditure. In other words, a pack at say 0=B0C might warm up to
15=B0C on a given drive but if it were at 15=B0C to begin with it might
only warm up to 20=B0C on the same trip. The other thing I have observed
is that the deeper the discharge the faster the pack warms up. This is
with a 200Ah TS LiFePO4 pack.

The coldest I have seen my pack was -3=B0C. On my 3 mile commute to
work, which is mostly down hill or level ground, the pack will rise
2=B0C with only a 4Ah discharge from 100%SOC. On this particular day the
pack was still at -1=B0C when I left work and was at 3=B0C when I got home
and the temp reading continued to clime a couple more degrees after
that. In this weather the trip home typically used 11-12Ah.

On Tue, Feb 28, 2012 at 12:32 PM, EVDL Administrator <[email protected]> wrot=
e:


> > On 28 Feb 2012 at 11:07, Jukka J=E4rvinen wrote:
> >
> >> Lithium cells do not lose capacity in cold.
> >
> ...


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