Caracalover
Posts: 560
Joined: Sat Jun 04, 2011 10:47 pm
Delivery Date: 12 Mar 2011
Leaf Number: 0567
Location: Tujunga
Contact: Website

Re: My Leaf Stats : Range vs Temperature

Wed Nov 09, 2011 10:59 pm

Ok, perhaps stupid questions, but I don't understand batteries well. I do know the stupidest question is the one that wasn't asked. All of these questions assume it is cold out, say below 30F.

If you can charge the battery when it is warmer, say midday instead of after midnight, will you get more energy into the battery pack?

Is it better to charge right after driving, while the battery has some heat from use if you want 100%? Likewise would it be better to start driving as charging ends to gain the heat produced when charging?

If you heat the cabin to 90 mid-charge, will that aid in getting more energy in the battery?

Last question is a scenario - You are headed to a mountain top to go skiing. It is 55 degrees where you live, you drive up to the resort which has temps below 30F. and will have an all downhill run to get home, so no need to charge as long as you can get started. You get there with 2 bars showing, say 20% SOC.
26,000 miles on Silver Leaf
wildcatzoo.org drive there on Sunday across a big mountain, sorry no public charging at this time.
Looking for grants to put in solar port so perhaps in the future...

SanDust
Posts: 1363
Joined: Fri Aug 06, 2010 10:54 am

Re: My Leaf Stats : Range vs Temperature

Thu Nov 10, 2011 2:19 am

LEAFfan wrote:With all those factors you mentioned, I've only lost 10%, nowhere near 25%. Heat will NOT kill the battery pack UNLESS it is 120 or hotter for 24 hours or more. Our summers will NOT hurt our battery packs, that's just FUD. So when you say 'heat', please quantify or it's just FUD.
If you're seeing a 10% reduction in range during the first week of November I may have underestimated the range hit. Next you'll be saying you don't understand how a 20 MPH head and tail wind will increase the energy needed to overcome drag by 30%.

As for heat, any operating environment (not ambient temperature) over 70F is potentially an issue. The hotter the cells get and the longer they stay hot the shorter their life will be. Given the complete lack of a thermal management system on the Leaf, Nissan will end up replacing some batteries.

As for FUD, the last time you mentioned that, you and and EVNOW were proclaiming that the Leaf's battery pack had a capacity of 32 kWh and that anyone who had a different view was spreading FUD. Maybe history does repeat itself.

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TomT
Posts: 10651
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Leaf Number: 000360
Location: California, now Georgia
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Re: My Leaf Stats : Range vs Temperature

Thu Nov 10, 2011 5:50 am

The cabin is completely isolated from the battery pack so heating the cabin will have essentially no affect on the pack.
Caracalover wrote:If you heat the cabin to 90 mid-charge, will that aid in getting more energy in the battery?
Leaf SL 2011 to 2016, Volt Premier 2016 to 2019, and now:
2019 Tesla Model 3; LR, RWD, FSD, 19" Sport Wheels, silver/black; built 3/17/19, delivered 3/29/19.

Herm
Posts: 3765
Joined: Sun May 23, 2010 3:08 pm
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Location: Timbuktu, Mali

Re: My Leaf Stats : Range vs Temperature

Thu Nov 10, 2011 6:07 am

TomT wrote:The cabin is completely isolated from the battery pack so heating the cabin will have essentially no affect on the pack.
It would be an interesting mod to have some forced ventilation of the batteries.

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TomT
Posts: 10651
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Re: My Leaf Stats : Range vs Temperature

Thu Nov 10, 2011 6:18 am

Nissan made the choice to go with no thermal management of the pack (other than the Cold Weather Package heater that kicks in at about -4F) and, in fact, the pack is sealed and under slight positive pressure.
Herm wrote:It would be an interesting mod to have some forced ventilation of the batteries.
Last edited by TomT on Thu Nov 10, 2011 6:58 am, edited 1 time in total.
Leaf SL 2011 to 2016, Volt Premier 2016 to 2019, and now:
2019 Tesla Model 3; LR, RWD, FSD, 19" Sport Wheels, silver/black; built 3/17/19, delivered 3/29/19.

defiancecp
Posts: 367
Joined: Mon Aug 16, 2010 4:02 pm
Delivery Date: 25 Aug 2011
Location: Little Rock

Re: My Leaf Stats : Range vs Temperature

Thu Nov 10, 2011 6:56 am

LEAFfan wrote:With all those factors you mentioned, I've only lost 10%, nowhere near 25%.

Well, it's nice that you're not having much loss, but that makes you the exception to what should be happening, and in my case IS happening. The difference in my observed efficiency -*without* the climate control running- between ambient of 70* and ambient of 45* is 4.3m/kwh on the dash and about 70m range down to 3.5m/kwh and about 58m range. That's around 20% down in both cases, and consistent with about 25% down by the time it drops into the 30's.

I hope you continue to have such great luck with yours, but I'd also hope you could avoid setting unrealistic expectations for readers who don't have their leafs yet. If I bought my leaf on the edge of warm-air range based on owners insisting that cold-air range wasn't much shorter, it would set me up for an extremely negative experience when winter hit.

Heck, even with that expectation, when it hit I still found it a bit surprising; took me a couple days to really adjust my expectations. Luckily it doesn't interfere with my range, so no problem there... although I may have to up to 100% charge on a more regular basis when it gets colder (right now I'm 100%-ing on Fridays only).

LEAFfan
Posts: 4828
Joined: Fri Apr 23, 2010 6:08 pm
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Leaf Number: 1855
Location: Phoenix Area

Re: My Leaf Stats : Range vs Temperature

Sat Nov 12, 2011 2:51 am

SanDust wrote:
LEAFfan wrote:With all those factors you mentioned, I've only lost 10%, nowhere near 25%. If you're seeing a 10% reduction in range during the first week of November I may have underestimated the range hit.
As for heat, any operating environment (not ambient temperature) over 70F is potentially an issue. The hotter the cells get and the longer they stay hot the shorter their life will be. Given the complete lack of a thermal management system on the Leaf, Nissan will end up replacing some batteries.
As for FUD, the last time you mentioned that, you and and EVNOW were proclaiming that the Leaf's battery pack had a capacity of 32 kWh and that anyone who had a different view was spreading FUD. Maybe history does repeat itself.
Underestimated? LOL, 25% loss is OVERESTIMATING range loss. 10% is nothing and that's only because of the denser air, nothing else. Show me the proof for your 'over 70' FUD. There is no way you can know ANY batteries will be replaced because of being over 70 degrees. That's just ludicrous. And show me the quote where we said 32kW h battery pack. I believe we said 28 and we were really close. It's 28.8kW h. That's straight from Nissan to the EEs that were involved with the AZ testing. There's a lot of things you seem you think you know, but you really don't.
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
4.8 kW DC PV ($ .91/W fully installed)/ Dec., 2010

LEAFfan
Posts: 4828
Joined: Fri Apr 23, 2010 6:08 pm
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Leaf Number: 1855
Location: Phoenix Area

Re: My Leaf Stats : Range vs Temperature

Sat Nov 12, 2011 2:54 am

defiancecp wrote:
LEAFfan wrote:With all those factors you mentioned, I've only lost 10%, nowhere near 25%.
Well, it's nice that you're not having much loss, but that makes you the exception to what should be happening, and in my case IS happening. The difference in my observed efficiency -*without* the climate control running- between ambient of 70* and ambient of 45* is 4.3m/kwh on the dash and about 70m range down to 3.5m/kwh and about 58m range. That's around 20% down in both cases, and consistent with about 25% down by the time it drops into the 30's.
I hope you continue to have such great luck with yours, but I'd also hope you could avoid setting unrealistic expectations for readers who don't have their leafs yet. If I bought my leaf on the edge of warm-air range based on owners insisting that cold-air range wasn't much shorter, it would set me up for an extremely negative experience when winter hit.
Heck, even with that expectation, when it hit I still found it a bit surprising; took me a couple days to really adjust my expectations. Luckily it doesn't interfere with my range, so no problem there... although I may have to up to 100% charge on a more regular basis when it gets colder (right now I'm 100%-ing on Fridays only).
It isn't misleading anyone. I've given our temps when I've had the reduction. I'm sure it will reduce more when it gets to 30 or 40 because the air will be even denser. I will let you know what happens.
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
4.8 kW DC PV ($ .91/W fully installed)/ Dec., 2010

Herm
Posts: 3765
Joined: Sun May 23, 2010 3:08 pm
Delivery Date: 29 Aug 2012
Location: Timbuktu, Mali

Re: My Leaf Stats : Range vs Temperature

Sat Nov 12, 2011 3:54 am

TomT wrote:Nissan made the choice to go with no thermal management of the pack (other than the Cold Weather Package heater that kicks in at about -4F) and, in fact, the pack is sealed and under slight positive pressure.
Yeah you would lose the pack seal, but it would be an interesting mod once the warranty is up on the Leaf. Another way to do it would be to run a freon loop with a metal pipe against the battery case.

Anyone put a remote temperature sensor on the battery case?

DaveinOlyWA
Posts: 15640
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Re: My Leaf Stats : Range vs Temperature

Sat Nov 12, 2011 7:48 am

have talked about this extensively recently and last spring. before we begin;

1) no change in driving destinations, patterns, speeds, routes, etc.

2) no climate control
3) no heater

4) no defrost (other than occasional bursts lasting less than one minute) used it exactly 3 times in past 8 days (off on normal. was sick and did virtually nothing for 3 days)

5) CLIMATE CONTROLS ARE NOT A FACTOR IN MY STATS

ok. hopefully that clears up some stuff.

so, have already presented this information several different ways. so am trying another tactic

below is miles/kw reading on my car (this sample is typical if you prefer a different date based on your stats for temps in the area, please ask) from April 1-8. the only thing i dont know is how much climate control has been used.

4.8
4.7
4.5
4.2
4.8
4.4
5.6
4.9

now lets take a random week during Summer when temps are likely to have highs ranging from mid 70- to low 80's (average summer high max'es out at 78º for August) stats start from Aug 1st and like April are consecutive days. the 4.5 day is 64 miles, 90% freeway at 65+ mph. the rest are my normal drive around town stuff.


5.7
4.5
5.3
5.6
5.3
5.4
5.8
5.9
6
5.9
5.6

now lets post the present starting Nov 1 to yesterday

5.0
4.4
3.8
3.9
4.2
4.6
4.7
4.3
4.8
4.6

the 3's are generally when SO drives. she turns the heat on full blast as she enters the car and leaves it that way. she quite frankly, does not know the meaning of conservation. (she also cannot turn off a light)

i have purposely not used climate controls to help illustrate this point (thank you Sherpa lined hoodie for your warmth!!) and it is usually warm enough at this time of year to get away with that.

bear in mind, its very cold in the mornings with temps in mid 30's typical. but my morning commute is done on empty streets from a garage fresh from hot shower with full mug of hot coffee, so i am comfortable. my 10 minute commute is not long enough to get cold.

the afternoon, i am not so lucky. the commute is generally 14 to 25 minutes, the car sits out in 10 acre parking lot all day and if it has been raining, cloudy, etc. the car will pretty much be in the upper 40's to low 50's which is typical at this time of year at 5 PM.

when it gets colder and i start to use heat to survive, my numbers will drop to the low 4s which occasional dips into the 3's (this is street speeds, freeway never reaches the 4's)

this is why i state (frequently) that my winter range is 75 miles which is based on 3.5 miles per k.
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; 19,653 mi, 93.47% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

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