edatoakrun
Posts: 5222
Joined: Thu Nov 11, 2010 9:33 am
Delivery Date: 15 May 2011
Leaf Number: 2184
Location: Shasta County, North California

Re: My Leaf Stats : Range vs Temperature

Sat Nov 12, 2011 9:21 am

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%. This is the same trip I made several times over the summer, and posted details of on this thread:

http://www.mynissanleaf.com/viewtopic.php?f=31&t=5423" onclick="window.open(this.href);return false;

My trip (each time with a 1 1/2 hour break at the halfway point (for a hike around Burney Falls) on 8/30 was 87.6 miles by odometer (85.5 miles by Carwings-see other thread for info on this 2.5% discrepancy) with between 5,000 and 5,500 ft. of total ascent and descent, carwings reports 16.8 kWh consumed and 5.1 m/kWh. I believe my total battery capacity after charging to 100%, was about 20.4 kWh.

When I made the (almost) identical drive on 11/8 of 88 miles (85.9 as reported by CW) CW reported 17.6 kWh consumed and 4.9 m/kWh. I believe my total battery capacity when I left home with a 100% charge was probably close to 19.4 kWh.

Both trips were made at about the same average speed, about 40 mph, and despite the elevation change, very little friction braking was required, on either trip. The main reason I think the cold weather reduction was slightly greater than 5% for the drive, is that I either had a window cracked open, or the AC set low, for much of the 8/30 trip. The difference in miles driven was due to a short detour I made for 50 minutes of L2 about 55 miles into the trip. In retrospect, this was probably unnecessary, as it looks like I would have made it home on 11/8 at about the “very low battery” warning, but that was not apparent at the time. I got a scant three bars from the charge session, and had almost one full bar showing when I got home.

Both initial charges were done to 10 bars, with a top-off to 100 % many hours later, and were all done in an open carport.

On 8/30 the overnight low was in the low 60’s, and the top off was done when the ambient temp had warmed to the mid 80’s , and my best estimate that the battery was probably in the 70’s at this time. The drive was done in temperatures of 80-95 degrees. I believe (but did not record) that the battery temp indicator remained at 6 bars for the entire trip.

The 11/8 top-up charge was done when the overnight low was 35. I doubt that the battery temp was much higher than this. The temperature during the drive ranged from 47 to 36 degrees. Battery temp showed 4 bars until the recharge session, and it was at 5 bars for the rest of the trip.

So this approximately 40 degree decrease in temp when charging, and 50 degree reduction when driving, resulted in about 10% recorded range reduction. I expect that If I’d done the 8/30 trip in “sauna” mode, with the windows up and AC off, it would result in more like 11-12%.

It gets much colder than 35 here during the winter, but I plan to start parking in my garage (unheated but insulated, and stays above freezing) once winter sets in, so I think this is pretty close to the maximum range drop I’ll see (until I turn on the heater and wipers...). I know lots of you will be driving in much lower temps, but I wouldn’t want to try a long no-heater test trip on a much colder day. I, like many others, have seen larger range drops in cold weather driving, but I think you have to look at other causes, such as the heater, rain and wet roads etc.
Last edited by edatoakrun on Sun Dec 11, 2011 10:06 am, edited 5 times in total.
no condition is permanent

edatoakrun
Posts: 5222
Joined: Thu Nov 11, 2010 9:33 am
Delivery Date: 15 May 2011
Leaf Number: 2184
Location: Shasta County, North California

Re: My Leaf Stats : Range vs Temperature

Sat Nov 12, 2011 9:32 am

DaveinOlyWA wrote: ...this is why i state (frequently) that my winter range is 75 miles which is based on 3.5 miles per k.
Have you noticed a larger decrease in range and m/kWh on rainy days?

I know the consumption of the wipers is negligible, but I'm wondering if the cumulative effects of increased drag, both caused by rain and wiper use, and wet road effects, add up to a substantial amount.

High speed driving in the rain sure seems to chew up bars, for me.
no condition is permanent

DaveinOlyWA
Posts: 15808
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Nov 2019
Leaf Number: 319862
Location: Olympia, WA
Contact: Website

Re: My Leaf Stats : Range vs Temperature

Sat Nov 12, 2011 10:04 am

edatoakrun wrote:
DaveinOlyWA wrote: ...this is why i state (frequently) that my winter range is 75 miles which is based on 3.5 miles per k.
Have you noticed a larger decrease in range and m/kWh on rainy days?

I know the consumption of the wipers is negligible, but I'm wondering if the cumulative effects of increased drag, both caused by rain and wiper use, and wet road effects, add up to a substantial amount.

High speed driving in the rain sure seems to chew up bars, for me.
my post is not to explain why the performance has dropped and yes, we have had rain but i do not see that parallel. for the most part, we have had several clear but colder days. i have to assume the loss of performance seen so far which is running about 15-20% so far is a combo of

lower tire pressures since ambient temps control air pressure in a closed container

higher friction from colder grease

higher rolling resistance due to wetter pavement

higher air resistance due to heavier air. but i feel that to be a lesser problem since my stats are all primarily days when i am not exceeding about 40 mph.

the days i posted are not exact routes, but typical of what i do. i have errands that are run weekly and it involves driving the streets of Olympia. my destination may vary a bit which is why i posted several consecutive days to emphasize that it simply does not matter.

now that my performance has dropped, i have made extra effort to hit the 5 mile/k plateau and with the exception of the one day (it was in the mid 70's btw. at least 15 º warmer than the rest of the week) I simply cannot do it without drastically changing my driving habits.

add to that, my Summer driving was FREQUENTLY not that efficient. i have to admit i tested my off the line speed more than a few times. i nearly always drove with all the windows rolled down which is what i prefer. i hate A/C and weather that requires it which i guess is why i live here. if you have not spent a week experiencing Puget Sound in the Summer, i highly recommend it. it is enough to put up with 8 months of rain!

as far as wipers? i posted my thoughts on it, because anything that makes the power needle move is not insignificant and the wipers jump the meter by 100-120 watts
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 25,047 mi, 92.12% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

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evnow
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Posts: 11480
Joined: Thu Apr 22, 2010 11:41 am
Delivery Date: 25 Feb 2011
Leaf Number: 303
Location: Seattle, WA

Re: My Leaf Stats : Range vs Temperature

Sun Nov 13, 2011 11:03 am

Here is a graph with better control. All these are my commute trips. Only thing not controlled is use of heater. I'm sure the few points below 4 m/kwh are with heater & rain. The ones above 4.5 are definitely with no heater (may be a bit of defrost on cold days).

Image

Between 70 & 40 degress - I'd say about 10% difference in efficiency (without the use of heater).
1st Leaf : 2/28/2011 to 5/6/2013
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LEAFfan
Posts: 4830
Joined: Fri Apr 23, 2010 6:08 pm
Delivery Date: 08 Jun 2011
Leaf Number: 1855
Location: Phoenix Area

Re: My Leaf Stats : Range vs Temperature

Sun Nov 13, 2011 11:59 am

evnow wrote:Here is a graph with better control. All these are my commute trips. Only thing not controlled is use of heater. I'm sure the few points below 4 m/kwh are with heater & rain. The ones above 4.5 are definitely with no heater (may be a bit of defrost on cold days).
Image
Between 70 & 40 degress - I'd say about 10% difference in efficiency (without the use of heater).
That sounds about right even though we haven't had 40's yet during our daylight hours. I've finally realized that the denser air, colder tires, etc. are the causes of lower m/kW h since I haven't used nor plan to use any HVAC. When our temps went back up into the mid 70's (from mid 50's to low 60's), my m/kW h went back to what I had been getting...6.8. It was hard to get 6.0 with the cooler temps!
2013 LEAF SV Del. 2/28/13
2013 LEAF World Record for Most Miles Driven On One Charge-188 miles/8.8 m/kW h
2022 LEAF SL+ Del. 9/18/21
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