leafdriving
Posts: 12
Joined: Sun Oct 08, 2017 3:25 pm
Delivery Date: 08 Oct 2017

Do "solar reflective" car covers help?

Mon Feb 19, 2018 2:51 am

This last summer (in the SF Bay Area) beat my battery up. It was unusually hot. I have to park outdoors and this year I'll be looking for shade. For the times that I'm unable to find shade, I was wondering if those "solar reflective" car covers on Amazon would help keep the battery temps lower. I know most are cheap and eventually tear but I don't mind as long as they last the summer and actually keep the battery somewhat cooler.

Anyone have a experience with them? Am I better off just hunting shade? Thanks!

SageBrush
Posts: 2910
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: Do "solar reflective" car covers help?

Mon Feb 19, 2018 7:17 am

Shade.
The battery is most affected by the hot pavement, not the hot roof or a hot cabin.

Black asphalt is the worst.
IIRC my measurements last summer, the road outside my home was 20F higher than my dirt driveway.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

LeftieBiker
Posts: 9802
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Do "solar reflective" car covers help?

Mon Feb 19, 2018 2:02 pm

What color is the car? If a light color don't bother with the cover. If it's black or dark red the cover might help a little, but the hot pavement remains a big problem.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

User avatar
DuncanCunningham
Posts: 518
Joined: Thu Mar 26, 2015 10:02 am
Delivery Date: 15 Apr 2015
Location: Bountiful, UT

Re: Do "solar reflective" car covers help?

Mon Feb 19, 2018 2:29 pm

park on the north side of buildings, under trees or on the grass. Shade is the best. but like a previous poster said.. if your car is black a cover might help.

Heat is also collected in the battery by rapid use and charging. so don't blister your starts and try to charge the car in the WEE hours of the morning, if you can. don't let it sit with 100% charge in hot weather.
Statler: Wake up you old fool. You slept through the show.
Waldorf: Who's a fool? You watched it.

2015 Leaf S (leased until May 2018, Bought out in Jan 2017)
2012 Leaf SL (purchased May 2015)

leafdriving
Posts: 12
Joined: Sun Oct 08, 2017 3:25 pm
Delivery Date: 08 Oct 2017

Re: Do "solar reflective" car covers help?

Sun Feb 25, 2018 6:56 pm

My leaf is white with black leather. I charge to 80%. I'll charge to 100% about once a month and drive it immediately after it's done. In the summer I only charged at night.
I don't care for the cabin temperature as long as it doesn't affect the battery. Last summer my Leaf spent most of the time on my driveway (concrete but with direct sunlight in the afternoon). It wasn't parked on asphalt but the battery temp bars were usually at 6, a few times it hit 7. I know the bars aren't really helpful but I can't think of anything else than heat that beat it up.

Would placing a large piece of cardboard under the car while parked on the driveway keep the battery cooler? Or should I invest in a tent of some sort to provide shade to the car and driveway? I'm open to any idea.

LeftieBiker
Posts: 9802
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Do "solar reflective" car covers help?

Sun Feb 25, 2018 10:27 pm

Try to park on one edge of the parking lot. A piece of foam insulation meant for use under house siding might help if placed under the car with the reflective side down...
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

GRA
Posts: 9498
Joined: Mon Sep 19, 2011 1:49 pm
Location: East side of San Francisco Bay

Re: Do "solar reflective" car covers help?

Mon Feb 26, 2018 3:47 pm

leafdriving wrote:My leaf is white with black leather. I charge to 80%. I'll charge to 100% about once a month and drive it immediately after it's done. In the summer I only charged at night.
I don't care for the cabin temperature as long as it doesn't affect the battery. Last summer my Leaf spent most of the time on my driveway (concrete but with direct sunlight in the afternoon). It wasn't parked on asphalt but the battery temp bars were usually at 6, a few times it hit 7. I know the bars aren't really helpful but I can't think of anything else than heat that beat it up.

Would placing a large piece of cardboard under the car while parked on the driveway keep the battery cooler? Or should I invest in a tent of some sort to provide shade to the car and driveway? I'm open to any idea.

Definitely park in the shade whenever possible, but if you have to park in the sun get one or more reflective window screens. I normally aim a car's windshield directly towards the sun (or where it will be late afternoon when the angle is lower and more direct) so that I only need a windshield screen. If you have to park sideways on, then getting some for one side of the car will be helpful. It will definitely keep the inside of the car cooler, and whether or not that high cabin temp significantly affects battery longevity, it will definitely affect the amount of energy expended to cool the interior down to a comfortable level. It may also improve the life of the vehicle interior (dash, seat fabrics etc.), and may also lessen outgassing of any nasty chemicals that might be included in said interior. It's a lot less hassle than a full car cover, although that would be the most effective. A white car already has a high albedo (see https://phys.org/news/2011-10-silver-white-cars-cooler.html ), so it's the windows (and the pavement, as others have noted) that are going to be the main cause of solar heating.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

DarthPuppy
Posts: 695
Joined: Sun Aug 11, 2013 8:45 pm
Delivery Date: 11 Aug 2013

Re: Do "solar reflective" car covers help?

Mon Feb 26, 2018 11:09 pm

GRA wrote: A white car already has a high albedo (see https://phys.org/news/2011-10-silver-white-cars-cooler.html ), so it's the windows (and the pavement, as others have noted) that are going to be the main cause of solar heating.

Cool article. Thanks for posting that. I'm now even happier with my color choices. 8-)
'13 Leaf SL
'18 Honda Clarity Touring PHEV

GRA
Posts: 9498
Joined: Mon Sep 19, 2011 1:49 pm
Location: East side of San Francisco Bay

Re: Do "solar reflective" car covers help?

Tue Feb 27, 2018 4:21 pm

DarthPuppy wrote:
GRA wrote: A white car already has a high albedo (see https://phys.org/news/2011-10-silver-white-cars-cooler.html ), so it's the windows (and the pavement, as others have noted) that are going to be the main cause of solar heating.

Cool article. Thanks for posting that. I'm now even happier with my color choices. 8-)

The last three of the four cars I've owned have been silver metallic ;) I like the color, but I really like not coming back to a car parked in open sun and opening the door to an oven (a friend has a black 4Runner, and we tend to alternate which car we take on trips). Even in desert summer the temp difference is noticeable, as is the case if I neglect to use the windshield shade, or park the car without pointing the windshield at the sun.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

Return to “General / Main Owners Forum”