Cold truths about electric cars' cold-weather shortcomings

[ALS]

Cold has a negative impact on all aspects of battery operation."

Charles Lane - WASHINGTONPOST - January 31, 2011

He may be on to something. My Prius has MPG issues when it goes below 45 degrees. --Ed.

Count me among the many thousands of Washington area residents who spent Wednesday night stuck in traffic as a snowstorm sowed chaos all around us. Being car-bound in sub-freezing weather for six hours can make a guy think. I counted my blessings. The situation could have been worse, I realized: My fellow commuters and I could have been trying to make it home in electric cars, like the ones President Obama is constantly promoting, most recently in his State of the Union address.

It is a basic fact of physical science that batteries run down more quickly in cold weather than they do in warm weather, and the batteries employed by vehicles such as the Nissan Leaf or the Chevy Volt are no exception.

The exact loss of power these cars would suffer is a matter of debate, partly because no one has much real-world experience to draw on. But there would be some loss. Running the heater to stay warm, or the car radio to stay informed, would drain the battery further. ... [Read More]

[Right Lane Cruiser]

I've no doubt there will be issues with low temperature functionality... though most of the reduction hybrid owners see in the winter has to do with the engine staying on much longer to keep everything up to temperature. One of the reasons I don't see as severe a drop as many Prius drivers is that I can still force the engine off in the Insight when I want it off.

I'm quite interested in the Focus EV partly because they have a "thermally managed" pack already specified as a standard feature.

On the other hand, Nissan was the one playing with lithium powered cars in the Arctic. I don't know what they have planned but I'm pretty sure they'll have a competent solution because cold weather performance isn't anything new to them.

Finally, my commute is so much shorter than the total range, I could lose over 50% of the range and still get back and forth just fine.

[WriConsult]

Also note that cold weather performance varies quite a bit by battery chemistry. The new EVs have different chemistries (Li-Mn or LiFePO4) than the Prius (NiMH). My understanding is the lithium chemstries are somewhat less affected by cold than NiMH.

[Bike123]

My bike light with LiIon (unknown chemistry) battery has worked at -10F, but has only cold soaked to 5F. The 20% remaining warning LED didn't come on, so it apparently didn't lose too much due to the temperature. The next couple of days will give it a tougher test.

[WriConsult]

Originally Posted by Bike123

My bike light with LiIon (unknown chemistry

Almost certainly Li-Cobalt, same as in laptops and cellphones.

[herm]

The Leaf does use insulation on the battery case, and probably will have heaters built in.. thus prewarming before you leave on the morning will help quite a bit.

Automotive OEM need to develop a low temperature heat pump for an electric car, probably using CO2 as a refrigerant.. even well below zero you can still get heating for half the power usage of a simple resistance heater...

[RichXKU]

Conditions like this are exactly why the EPA needs to provide ranges for multiple conditions.
City and steady-state 65 MPH highway for:
20°F, heat on
60°F, no climate and
90°F, AC on.

Those 6 data points provide a lot of insight without confusing anyone.

[Earthling]

I took my '07 to the dealer yesterday for the free inverter water pump swap. Temperature was mid-teens F. My mpg to the dealer was 52.5 mpg. While that is down from warm temperature numbers, it is still pretty darned good.

Harry

[PaleMelanesian]

Originally Posted by RichXKU

Conditions like this are exactly why the EPA needs to provide ranges for multiple conditions.
City and steady-state 65 MPH highway for:
20°F, heat on
60°F, no climate and
90°F, AC on.

Those 6 data points provide a lot of insight without confusing anyone.

I'd take it a step farther. For each of those temperatures, give a mpg-vs-mph chart or table. Not only will it give useful information for comparing, it will also help educate people about the waste involved in high-speed driving.

[ItsNotAboutTheMoney]

Originally Posted by PaleMelanesian

I'd take it a step farther. For each of those temperatures, give a mpg-vs-mph chart or table. Not only will it give useful information for comparing, it will also help educate people about the waste involved in high-speed driving.

Right. Just put some frigging graphs on there.