Electric Vehicles and US' current cold snap

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Seeing EVs touted as the future, the abandonment of discussions regarding cold start idle etc...and that cranking batteries may be down by over 50% on these extreme mornings.

Got me wondering about EVs in the US, particularly the cold.

First up, is it just lead acid that will lose 50% in the extreme cold ?

Secondly, heating how to ?
 
"In general, Lithium-ion cells cannot be charged below 0 degrees Celsius, which would theoretically prevent charging in cold environments. To overcome this cold weather charging obstacle, the Roadster is designed with a heater to warm the cells (when plugged in) to an appropriate charging temperature. If there were no battery pack heater, drivers living in cold environments would have difficulty charging and experience stunted driving performance.

Likewise, the cells are designed to operate in high-temperature environments. High-performance driving is possible in even the hottest environments of the world. If the temperature rises above a set threshold, the air conditioning unit sends chilled coolant through the pack. Similar to the radiator fan of ICE-powered cars, the chilled coolant continues to circulate after the motor has been turned off to keep the temperature at an appropriate level. Cooling the pack enables a driver to quickly charge immediately after hard driving in hot climates. Without such a cooling system, recharging in hot weather would be delayed after each drive."


http://www.teslamotors.com/roadster/technology/battery
 
Leave car plugged in, start car and turn on the heat / defrost.

Once car is warm inside, (60 - 70) unplug and depart.

Some have a "Departure Time" feature that will pre-warm the car up and have it ready at a preset time...

Don't run the heat unless necessary, use the seat heaters. It's a lot less current draw...
 
Originally Posted By: Shannow
Secondly, heating how to ?

Automakers love to brag and show videos of how they test their cars in Death Valley and in the Arctic. I would like to see the same with EVs, particularly in the Arctic. Let's see how warm an interior gets when it's -40 outside.
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Originally Posted By: dparm
Most of them have battery warmers, but range will still suffer.


The fit ev suffers really bad. Goes from like 60 mile to 15 mile range
 
GM has had issues with the electric heating system in the Volt. Owners have complained of woefully inadequate heating during EV driving mode in cold temps. The only solution is stronger electric heaters with the higher draw/lower range penalty they exact (not sure if the newer models have addressed the heating issue). It's predicted to get to -25F here by tomorrow night...seat heaters don't cut it when it's that cold (though they help a lot during milder weather).
 
There's always a good old fashioned gasoline fired heater:

South%20Wind%20Car%20Heater%20-%2019480927%20Life.jpg


Oh yeah, there's the issue of getting gasoline to it, minor problem.
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Originally Posted By: mattwithcats
Don't run the heat unless necessary, use the seat heaters. It's a lot less current draw...



So for good mileage you have to go without heat.. Hybrids are great!
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...or you can improve insulation, AC behaviour and waste heat management to get the heat up. Traditional cars have plenty of waste heat to use for heating purposes, so it hasn't gained much attention until now.
 
Starting at -30, insulation doesn't gain much while the interior thermal mass gets up to temperature...and all the heat that is required to do so comes from the grid...which has already given up it's inefficiencies.
 
Originally Posted By: Nebroch
...or you can improve insulation, AC behaviour and waste heat management to get the heat up. Traditional cars have plenty of waste heat to use for heating purposes, so it hasn't gained much attention until now.


This is correct, but it also shows yet again that hybrids are still a work in progress. Great concept. I'm sure they do excellent in moderate temps where the AC and heat don't have to be ran.. but for the person who lives in the colder or hotter temps they might as well be driving a diesel Jetta for fuel economy.
 
I'm surprised some didnt install wood stoves in the back seat,so mileage wouldnt suffer.Oh yea,theres the issue of the emissions from burning the wood...EPA wouldnt approve...
 
Originally Posted By: NHGUY
I'm surprised some didnt install wood stoves in the back seat,so mileage wouldnt suffer.Oh yea,theres the issue of the emissions from burning the wood...EPA wouldnt approve...


Hahahahaa! That sounds exactly like something I'd say.....
 
Li-ion will not charge properly below approximately freezing temperatures, but will perform well down to -35 C. Automobile batteries are already 50% derated, so exercising them at normal rates is possible! though the are heaters and other tricks that are played to make the operations as conservative as possible.


A cooler battery is a happier battery because the degrading side reactions are all Arrhenius style reactions. Different chemistries will operate below freezing, but they usually have an energy penalty for other reasons. Mint go too hot either. 60C is a good cutout.
 
I was behind a Tesla this morning getting coffee at the drive threw. They are just normal cars, people have to get past the EV thing.

I think they have a pre condition feature for the cabin which is nice, I wish my gas truck had that!
 
Hybrids and EV's are not perfected yet. I thought most knew that..... With my current commute of 8 miles round trip, I will look at a Tesla when they come out with the $30,000 sedan. I'm married, and my wife works from home. I would keep a "traditional" car for her, so I would have no issues with range or travel.
 
Hybrid is easier to adapt for winter conditions, as IC engine exists and you can recover heat from exhaust (like Toyota does) etc.

Lexus CT 200h (Prius in a different body) actually came second in local automotive magazine's test in 2012. They tested cold consumption, cabin warm up time and handling properties for example. I have to admit though, that other contestants in that test were typical european cars with small engines and/or diesels, so it wasn't too hard to be one of the best.
 
Originally Posted By: JHZR2
Li-ion will not charge properly below approximately freezing temperatures, but will perform well down to -35 C. Automobile batteries are already 50% derated, so exercising them at normal rates is possible! though the are heaters and other tricks that are played to make the operations as conservative as possible.


What sort of percentage power consumption would said heater draw when the vehicle is sitting charged on standby (e.g. work carpark, unplugged) ?
 
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