Piles of Tesla owners stranded at charge stations abandons their EV's.

[mikeselectricstuff]

I'm honnestly curious: why is that BS? 'Regular' diesel craps out at about -5C. With additives, maybe -20C.. That's what I was told, have things changed?

I'm not an expert about diesel vehicles, but as far as I know, and I have owned a diesel vehicle here and operated it without issues down to -30degC, there are winter grades that go significantly below -20, something like -35 is not a problem if everything's right both with the fuel and the vehicle. Yet in real world, not everything is perfect. Failures with diesel vehicles - and not only failures to start, but actually failures after driving for some time - go steeply up below -30degC. It's not 100% failure, but even 1% failure rate is pretty bad when you have thousands and thousands of lambs commuting at the same time. At something relatively mild weather like -15..-20degC, the only way to make them fail is to erroneously use summer grade diesel.

ISTR that in some very cold regioons, it's common to have mains power available at (truck?) parking spaces for engine block heaters

[PlainName]

[radar_macgyver]

It's a shame that Hertz is cutting back on EVs - I found them very easy to rent, even in relative "charging deserts" like rural Virginia or South Carolina. I would just pick a hotel that had a slow charger on site (usually free), and Hertz' policy was to return the car with >70% charge. That avoids the usual last-minute run-around to find a gas station right before returning the rental. I rented a Tesla just once, and couldn't get used to the controls (picture rush-hour SF Bay Bridge traffic, digging through three levels of on-screen menus to figure out why the effing auto wipers wouldn't turn on). After that I've rented Polestars (or more recently, a Bolt EV).

Temps here have got down to -25 C and my own Bolt EV limited its regen rate. I couldn't tell if the discharge rate was limited, but as @Siwastaja pointed out, the roads were too icy to take advantage of that anyway. There was a pronounced drop in estimated range, too.

[Siwastaja]

What makes chargers not work when cold?

Mostly the same reasons why they don't work when warm - stupid idiots overdesigning secondary functions, mostly related to things called "software", "cloud" and whatever. Very rarely the power electronics, or the connectors, or low-level firmware have any problems. In my opinion, poor reliability of public charging points due to poorly designed software, mobile applications etc. is the #1 problem for EVs right now, because you have to plan such that you always have 2-3 charging sites available within your battery range in case they are all broken at one site, and this is A LOT of wasted resources, because someone financed and built those stations.

But I hope this is getting better, especially EU forcing one-time payments without a mobile app.

[Siwastaja]

I think the problem with EV chargers in cold weather is cold soaked EVs charging slowly.

This reduced charge rate coupled with increased need for charging is the issue. If you "normally" have 50% of usage of the infrastructure, now at cold this exceeds 100% and queuing ensues. This is also why the larger battery pack is the answer: not only it reduces the need to charge at all, it also increases the charge rate given the same conditions, as the charge rate in certain temperature is relative to pack capacity (e.g. 0.5*C).

[nfmax]

I never really had problems driving a  diesel at -10 to -20 degrees C. During winter there are extra additives in the diesel fuel to make it useful at low temperatures but this diesel is only sold in the winter. So if you aren't using the car often enough and thus end up using 'summer diesel' in the winter, you could run into trouble.

That must be the problem with the Teslas in the OP - people were charging them using summer electrons!

[TimFox]

A little background about midwestern US weather leading up to the charging station difficulties:
Up until roughly Jan 10, the central US had been having a mild winter, with Chicago temperatures above historical averages and daytime temperatures above freezing. 
That was followed by a cold snap, which still persists as of this writing (Jan 16).
During this cold period, Chicago daytime temperatures have been around 0 F (-18 C).
(The joys of a continental climate; Chicago proper is moderated slightly by Lake Michigan, but its effect is much less than the oceans’.)
Following the problems at suburban charging stations on local TV news, many ev drivers were surprised at how fast they lost battery charge in the suddenly frigid weather and overcrowded the stations, resulting in some vehicles losing all charge while waiting for openings.
Charging plug’s being dropped into the snow and icing up didn’t help.

[Siwastaja]

It's hilarious when the anti-EV conspiricy nutters claim that EVs are about "them" controlling you, when ICE cars are 100% dependent on fuel supply, whereas there will always be electricity, ultimately from your own wind/solar if you want complete independence.

These "free thinkers" are usually controlled by such super simple propaganda that the obviousness of it is nearly hilarious. I'm not saying large masses are not being controlled, but it's much less obvious, and much less severe. "Free thinkers" seem to be worst - all you need to do is to say anything which is opposite to mainstream, and then you get any idea through, such as our daily lives being controlled by a scarce resource moderated by a few large superpowers being a good thing, and something that breaks free of this chain of control being evil.

[PlainName]

What makes chargers not work when cold?

Mostly the same reasons why they don't work when warm - stupid idiots overdesigning secondary functions, mostly related to things called "software", "cloud" and whatever. Very rarely the power electronics, or the connectors, or low-level firmware have any problems.

How does software go wrong, or stop working or whatever is happening, when it's cold? The only way that can happen is if there is code which says, paraphrase, "if (temp < x) print "sorry, too cold to work"".

OTOH, open pretty much any datasheet and it will say working temperature 0-70C, storage 'a bit wider range'. For -20C you're looking at expensive parts, and if they don't want to pay for those then that's not really a software problem.

[tom66]

I think the problem with EV chargers in cold weather is cold soaked EVs charging slowly.

This reduced charge rate coupled with increased need for charging is the issue. If you "normally" have 50% of usage of the infrastructure, now at cold this exceeds 100% and queuing ensues. This is also why the larger battery pack is the answer: not only it reduces the need to charge at all, it also increases the charge rate given the same conditions, as the charge rate in certain temperature is relative to pack capacity (e.g. 0.5*C).

Well, it's one answer to the question but I'm not convinced it is the right answer.

The better route is watching battery technology progressively improve and seeing fast charge rates increasing even at low temperatures, it's clear this is going to be less and less of a problem when combined with an increase in the availability of chargers.  If charging companies use systems like Kempower's satellites, you don't even need to install a lot of power electronics.  You could build a 5MW power electronics cabinet that can serve up to 100 cars with 50kW each, or 50 cars with 100kW and so on.   Since charging curves vary a lot between models and SoC this can serve many users at once at their optimal charging rate.

If you're worried about winter road trips now, then perhaps just hang on before committing to an EV, that's okay...  They aren't for everyone (yet).

Big batteries have lots of side effects: the car gets heavier (hich affects handling, safety, road wear and efficiency), the car gets more expensive (so less people can afford them) and the car uses more resources to manufacture so you need bigger battery factories, more mining for materials, and have a higher carbon impact.

IMHO carrying more than 60-70kWh for a normal hatchback sized car is a bit silly.  I don't really understand the ID.3 78kWh Family model for instance.  In its first edition it was too heavy to have a 5th seat!  The 58kWh ID.3 is pretty ideal for a modern car.  You can do 3 hours of driving without stopping to charge and the battery is large enough that it can accept reasonable rapid charging rates (100-130kW).  The way to improve it would be making that rapid charge rate higher, like 200kW.  Which cars like Ioniq 5 can do already with similar sized batteries.  I just didn't do enough road trips at the moment to justify the extra expense on the Ioniq 5 - it was ~£10,000 more than my ID.3 was for an equivalent, at the time - but I doubt the cells Hyundai are using are particularly special it's just a matter of that technology trickling down to other models eventually.

[Siwastaja]

How does software go wrong, or stop working or whatever is happening, when it's cold?

You missed the point. My point was, the rate of charging station failures does not go up with colder temperature that much; they fail too much even in nice summer weather. It is just that as charging becomes even more important, we focus on those failures more. So the software failures I referred to are temperature-independent.

[nctnico]

What makes chargers not work when cold?

Mostly the same reasons why they don't work when warm - stupid idiots overdesigning secondary functions, mostly related to things called "software", "cloud" and whatever. Very rarely the power electronics, or the connectors, or low-level firmware have any problems.

How does software go wrong, or stop working or whatever is happening, when it's cold? The only way that can happen is if there is code which says, paraphrase, "if (temp < x) print "sorry, too cold to work"".

OTOH, open pretty much any datasheet and it will say working temperature 0-70C, storage 'a bit wider range'. For -20C you're looking at expensive parts, and if they don't want to pay for those then that's not really a software problem.

It is not the software but communication modules, displays, buttons, etc which don't work when cold or hot IF these are not designed for the environment. Unfortunately some are hugely confident in using modules bought from Aliexpress for such applications.

[Siwastaja]

The better route is watching battery technology progressively improve and seeing fast charge rates increasing even at low temperatures

This is the point: by watching battery technology improve, you get increased capacity and increased fast charge rates, due to the sheer capacity. This is exactly what we can see: energy and power density of state-of-art li-ion has increased in perfect sync, i.e. the "C-rates" of the cells have not changed much. Anyone who claims "10-minute 20%-80%" as their target is therefore on the wrong track; increasing power capability alone is a compromise which decreases energy density and increases cost per kWh significantly. This is not what we need. We need cumulated small improvements in energy density and cost per kWh, which comes with similar cumulative improvements in charge rates.

I agree with you that 60-70kWh is pretty much the sweet spot, given the weight and cost issues which prevent going much higher. I have also first hand experience how a 35-40kWh pack requires planning and special care, "the EV mindset". Even with 70kWh you are not perfectly free of it, but it's much more convenient experience which more resembles driving a gasoline car, but without having to fill the tank so actually better! There still is a tad of range anxiety left at 60kWh, but it's much less severe than at 40kWh.

It is true though that a 60kWh pack is still quite heavy which is suboptimal for consumption and tire wear. Which is why we are watching battery technology improve. I would like the 60-70kWh class get lighter and cheaper (instead of adding even more capacity) and become THE standard "people's car" class, but at the same time, 35-40kWh class slowly disappear, just like the 2010-era 20kWh class has all but disappeared. As it stands now, quick charge stations are pretty much lined up with those vehicles that absolutely need that extra "20-minute" so actually 50-minute "EV stop" on a trivial trip like visiting grandpa's during winter time.

[Halcyon]

It's not going to be pretty, but quite obviously the current fossil thing isn't pretty either - when the temperature hits -30degC, there is epidemic of diesel vehicles dying and needing a tow, so 

I don't think that's ever been the case? Those living in cold conditions would be using diesel specific to those conditions. Diesel used in Scandinavian countries work far colder than -30 C.

In Australia, "winter diesel" is sold around Canberra and the alpine regions for this very reason.

[EEVblog]

It's hilarious when the anti-EV conspiricy nutters claim that EVs are about "them" controlling you, when ICE cars are 100% dependent on fuel supply, whereas there will always be electricity, ultimately from your own wind/solar if you want complete independence.

I did a poll last week:

[themadhippy]

I don't think that's ever been the case? Those living in cold conditions would be using diesel specific to those conditions

Certainly was in the past here in the uk,but then we've never been  geared up for the wrong type of  weather,even our railways suffer with the wrong type of snow

[Halcyon]

I don't think that's ever been the case? Those living in cold conditions would be using diesel specific to those conditions

Certainly was in the past here in the uk,but then we've never been  geared up for the wrong type of  weather,even our railways suffer with the wrong type of snow

Maybe the UK is the exception. But you guys claim it's a heatwave once it hits 30 degrees. We call it a warm summer's day. 

[floobydust]

I looked at what went wrong in Chicago with the Tesla charging and it's not clear.
The company knows damn well what happened, they have the telemetry and should issue a press statement lest EV's get demonized for the wrong reasons.

I would expect a cold Tesla to refuse charging until the heater got the battery temps up, courtesy of the charger power, and then inititate charging at reduced rate.

But they would be really worried about battery Li-plating- which is terribly destructive to the batteries.
"Degradation of LiBs during operation is one of the most complicated and critical issues that involve the variety of electrochemical side reactions in all the LiB components. Lithium plating is one of the most important degradation mechanisms of the anode electrode. The main impact of lithium plating is severe capacity fade. It occurs under three main working conditions: low-temperature charging, high C-rate charging, and high SOC charging."
source: Progress in Energy and Combustion Science Lithium Plating Mechanism, Detection, and Mitigation in Lithium-Ion Batteries

Most of the unhappiness in Chicago, it appears due to the huge battery capacity temp derating, almost 1/10 capacity at low temps so the sudden range cut freaked people out. I haven't compared newer LiPO4 how they do.
People expected the usual 45 minute charge time, and while waiting for a charger station, things cool off. The battery is a stuctural component and imagine how much heater power/time it takes to heat a 1,000lb blob plus metal casing.

Diesel engines work fine here, there is a block and fuel heater but truck stops leave semi's idling constantly though. They never shut the engines off on big trucks.

[pickle9000]

[tom66]

I looked at what went wrong in Chicago with the Tesla charging and it's not clear.
The company knows damn well what happened, they have the telemetry and should issue a press statement lest EV's get demonized for the wrong reasons.

I would expect a cold Tesla to refuse charging until the heater got the battery temps up, courtesy of the charger power, and then inititate charging at reduced rate.

This is pretty much what happens.  The car will still drive okay (at very reduced power) if the battery is cold but charging isn't possible until the battery has warmed somewhat.   Someone tested this, it took a good 45 minutes before their battery was hot enough to start accepting actual charging current.


It realistically isn't a problem until you get into -15C weather conditions, sustained for several days, and then get a lot of people who need to travel all at the same time, all without preheating their battery... perhaps because they know the supercharger is there and don't need the nav.  But the problem is average people used to fuel powered cars don't necessarily get this.  It's not necessarily an easy concept to explain.  I mean it takes enough effort to explain to people it's faster to leave a supercharger at 60% than 90%...

[thm_w]

This is pretty much what happens.  The car will still drive okay (at very reduced power) if the battery is cold but charging isn't possible until the battery has warmed somewhat.   Someone tested this, it took a good 45 minutes before their battery was hot enough to start accepting actual charging current.
youtube.com/watch?v=i-c8AUeKs5c

Interesting, surprised it takes that long with ~5-7kW heat going into the pack from -15C. 480kg of material + losses to the outside, maybe thats just what it takes.

[floobydust]

The cars are under-engineered or... hiding something.

Tesla can easily thermal model the battery pack/heater, it knows ambient temperature, and can estimate the energy required to heat or maintain the pack temperature.
Tesla can easily thermal model the cabin temperature and heater, it knows ambient temperature, and can estimate the energy required to heat or maintain the interiour temperature.

The cold battery capacity reduction is huge and we should all hush hush about it lol. It's likely protecting against battery damage at the expense of a dead car.

Graph is a popular notion the media promotes and does it include the heaters running?

[Siwastaja]

Graph is a popular notion the media promotes and does it include the heaters running?

Worse, it probably includes heaters running set for some ridiculously high cabin temperature like +23degC. -4F is just -20degC. Even my Nissan Leaf which has no battery heating, no thermal insulation, nothing fancy, gets more than 50% of the summer range at -20degC, even when it sits in the cold on my driveway, as I don't have a garage. For example last night it was -28*C for a few hours so the battery pretty much cooled down, in the morning it was -18*C and my consumption for the 60km drive was 22kWh/100km, when during summer it is like 16kWh/100km. But I did preheat the cabin and that is lacking from the number, so it would actually be 25kWh/100km. A lot more than in summer, but not even close to double. Then again, my cabin temperature is set at +16*C, which I feel is totally comfortable because it's obvious to me to put clothes on during winter time, and not count on parking right next to the door at the destination, which might be what American's are doing?

[Siwastaja]

But they would be really worried about battery Li-plating- which is terribly destructive to the batteries.

It really is, but remember it's a combination of three factors: high state-of-charge, low temperature, and high charging current. If you pick all three, you are going to have serious battery damage. But if you pick two, it's already better.

In real world, one usually does not need to charge a pack which is already nearly full, so it rules out one of the factors. (At the end of charge session, the battery pack has heated up already so charging can commence fully.)

In really extreme temperatures say -35degC though, charging currents need to be limited to very modest values even for, say, 50% SoC. It's probably tempting for a manufacturer to completely disable charging and take the PR hit. Now it is matter of taste whether you should be just pre-heating with 5kW and not charge, or pre-heat at 5kW and at the same time charge at 5kW. The end result is not too different - if you are expecting charging power of 100kW, and actually getting 50kW average out of the sessions, both options (only heat, no charging; or heat + slow charging) are very slow to start and the difference on average session charge rate is not big.

[SeanB]

I don't think that's ever been the case? Those living in cold conditions would be using diesel specific to those conditions

Certainly was in the past here in the uk,but then we've never been  geared up for the wrong type of  weather,even our railways suffer with the wrong type of snow

Maybe the UK is the exception. But you guys claim it's a heatwave once it hits 30 degrees. We call it a warm summer's day. 

Remember once, while watching CNN at tea time (Gulf War 1, we loved the real time reporting, and often got a lot of pilots coming in to watch, because we had a TV set that could get the broadcast no problem, but their one was in the shadow area from the mountain), we were treated to a part of the news hour about how London was sweltering under a summer heat wave, and people were dying, and it was 31C. Turned to my colleague Raven, and asked him when was it 31C here. He replied it was around half past seven in the morning, and currently was just under 40C. This was indoors. And in winter.