AAA: Extreme temps significantly degrade electric car ranges ("extreme" = 95 and 20 degrees)

[Bill USA]

http://usatoday30.usatoday.com/MONEY/usaedition/2014-03-20-AAA-Range-of-electric-cars-cut-by-57--in-cold-weatherUSABrd_ST_U.htm

The range of electric vehicle can be greatly reduced, by up to 57%, depending on the temperature outside, auto club AAA says.

The AAA Automotive Research Center in Southern California found that the average range of an electric car dropped 57% in very cold weather -- at 20 degrees Fahrenheit -- and by 33% in extreme heat, a temperature of 95 degrees.

"We expected degradation in the range of vehicles in both cold and hot climates, but we did not expect the degradation we saw," said Greg Brannon, AAA's director of automotive engineering.

AAA conducted a simulation to measure the driving range of three fully electric vehicles -- a 2013 Nissan Leaf, a 2012 Mitsubishi iMIEV and a 2014 Ford Focus Electric Vehicle -- in cold, moderate and hot weather. It tested the vehicles for city driving to mimic stop-and-go traffic between December and January, fully charging each EV, and then "driving" each on a dynamometer in a climate-controlled room until the battery was fully exhausted.
(more)

since they didn't specify this, I'm guessing in the high temperature test, they didn't have the air conditioning on in the cars. On a 95 degree day, with humans in the car, you can be pretty sure the A/C will be on. Also, testing a car in a lab with the air temperature at 95 degrees does't come close to driving a car in stop and start "rush" hour traffic on a 95 degree day - heated highway. The air temperature just above a highway in the afternoon (as in afternoon 'rush' hour) is significantly hotter than the air temperature reported by the Weather bureau. I'm going to hazard a guess that with A/C on and driving on a highway with traffic and solar heating going on, that range degradation will be considerably higher the 33% AAA reported for 95 degrees.

Obviously, not every day is going to be at least 95 degrees or hotter or 20 degrees or colder but some fraction of the days in a year will meet these criteria. And on [font size="+1"]those[/font] days the range degradation could be very important.

[randys1]

1. Big issue, needs addressed by Tesla, somehow.

[happyslug]

2. This was a huge problem for Lead Acid Batteries, but should NOT be for Lithium batteries

Lithium Batteries have a much wider temperature before they degrade, but some how these tests seems to duplicate what would be expected from a Lead Acid Battery.

Lead Acid Batteries discharge rapidly as temperature nears freezing and drops below freezing:

http://pvcdrom.pveducation.org/BATTERY/charlead.htm

Thus for years, you were told to change you lead acid battery in your car before winter (Generally every four years), if the battery was going to fail to turn over the car, it would be when it had the least charge i.e .when temperatures were below freezing.

Lithium Batteries do not discharge in cold temperature anywhere near what Lead Acid Batteries do, but have some problems with high temperatures:

http://www.electricvehiclewiki.com/Battery_Capacity_Loss#Factors_Affecting_Battery_Capacity_Loss

Just a comment that seems to duplicate Lead Acid Batteries results not what Lithium batteries (And all three cars have Lithium batteries) can do.

[Yo_Mama]

3. The cars they were testing had lithium batteries.

It's not so much the battery as additional demands on the vehicle, most esp. heating and cooling.

[Yo_Mama]

4. Also, that's about CAPACITY loss, not the effect of high/low temps

Over time lithium ion batteries will lose capacity, but they do lose it more slowly than lead batteries.

[drm604]

5. Read this from the article:

The likely reason: There's only once source of power in an electric vehicle -- the battery. If battery power is being used to heat or cool the battery, it takes power away from the vehicle's range, he said.

If this is the correct explanation then, unless they can somehow make it unnecessary to heat or cool the battery, changes in battery technology won't help with this.

[nationalize the fed]

6. RE: AAA: Extreme temps significantly degrade *electric* car ranges

Should read:

AAA: Extreme temps significantly degrade *battery only* electric car ranges

Because Hydrogen Fuel Cell Electrics aren't similarly affected. That could be one reason the engineers at Toyota, Hyundai and Honda (who are much less emotionally involved in batteries than many posters here) have decided that Hydrogen Fuel Cell Electrics are better overall than Battery only electrics

Obviously, not every day is going to be at least 95 degrees or hotter or 20 degrees or colder but some fraction of the days in a year will meet these criteria. And on those days the range degradation could be very important.

The Leaf Owners have a lot to say about heat and lithium batteries

http://www.mynissanleaf.com/viewforum.php?f=9&sid=2defb8ad0adb1097ce5b07677248e557

http://www.mynissanleaf.com/viewforum.php?f=31&sid=2defb8ad0adb1097ce5b07677248e557

The replacement cost of a Nissan Leaf battery is $5,000 + tax and installation. There goes the savings on gas.

Did you know that a 40 mile range(city) for a 2011 LEAF with 35,000 miles is within specifications, and is performing as it should?...

...AAA was willing and ready to total my LEAF based on this drastic performance issue, but they were told by Central Valley Nissan and the LEAF mechanic that my LEAF is performing within specifications for a 2011 LEAF with 35,000 miles. I find this hard to believe based on the EPA estimates of 106 city / 92 highway (I am curious if other LEAF owners know that when their vehicle is 3 years old and has 35,000 miles; they will only get 40 miles per charge)...

The LEAF after two to three years of capacity degradation is at best a 40 to 60 mile range vehicle, and in cold weather if you like a heated cabin is more like a 30 to 35 mile range vehicle.
http://www.mynissanleaf.com/viewtopic.php?f=27&t=18194