this post was submitted on 06 Mar 2024
32 points (97.1% liked)

[Dormant] Electric Vehicles

3201 readers
2 users here now

We have moved to:

[email protected]

A community for the sharing of links, news, and discussion related to Electric Vehicles.

Rules

  1. No bigotry - including racism, sexism, ableism, casteism, speciesism, homophobia, transphobia, or xenophobia.
  2. Be respectful, especially when disagreeing. Everyone should feel welcome here.
  3. No self-promotion.
  4. No irrelevant content. All posts must be relevant and related to plug-in electric vehicles — BEVs or PHEVs.
  5. No trolling.
  6. Policy, not politics. Submissions and comments about effective policymaking are allowed and encouraged in the community, however conversations and submissions about parties, politicians, and those devolving into general tribalism will be removed.

founded 1 year ago
MODERATORS
 

I (still) don't own an EV for various reasons, but I'm still interested. One question that keeps popping up in my mind is this one:

Where I live way up north, many people drive EVs - mostly Teslas apparently. A solid third of the parking lot at work is filled with EVs. The one thing that always strikes me when I leave work around the same time as everybody else is the sheer amount of noise of all those Teslas warming up their batteries before their owners come out to drive home make in the winter: it's like dozens of heating cannons running at the same time.

Each time, I wonder how much juice is used just to prime the battery before use vs. actual miles traveled.

If you leave in a cold country, have you worked out how much energy you burn simply keeping the battery alive in the winter? Is your EV still more energy efficient than an ICE in the winter for your particular use pattern?

top 15 comments
sorted by: hot top controversial new old
[–] [email protected] 26 points 8 months ago (1 children)

They'd almost certainly still be more efficient.

EVs are 75-80% efficient at using their electrical power.
ICEs are 15-30% efficient at using their chemical power.

Until the battery looses 45% of it's capacity due to cold, it's not even close.

[–] givesomefucks 13 points 8 months ago (1 children)

Not to mention extremely cold climates gas doesn't work well either. People use diseals which require electronic heaters.

It's a niche market, but not impossible to engineer an EV with something like that.

If we're doing that using cabin heat to heat the battery while in use would help too.

It really wouldn't be hard to mitigate the effects of cold. There just isn't a market to justify it yet

[–] [email protected] 7 points 8 months ago (1 children)

Gasoline works better in cold climates than diesel. But once you get around -20 to -30°C and colder all vehicles will need an engine block heater to start reliably. The oil gets too thick.

And the batteries start to freeze if they have a slight drain. So lots of the time if you don't run your vehicle for a week or two you'll need a new battery because the lead acids freeze and are ruined when their voltage drops.

I think it will be tricky but not impossible to mitigate the effects of extreme cold on battery life. All the cabin heat is made by the EV battery anyways right?

[–] mephiska 3 points 8 months ago (1 children)

Cars with heat pumps scavenge heat from the motor(s) as well.

[–] [email protected] 2 points 8 months ago

Yeah I don't know a ton about EV's because I need to be able to drive 500km+ on a tank for work and life out here. Be kinda cool to have one as a work truck someday though be handy to have that much power available for running things.

[–] FlowVoid 15 points 8 months ago* (last edited 8 months ago)

Your coworkers are remotely heating their interiors, so they can be more comfortable as they start driving home.

If they didn't do this, the car would still work but they would have to sit on cold seats, like savages.

[–] [email protected] 11 points 8 months ago

Obviously and massively.

[–] [email protected] 9 points 8 months ago (1 children)

Yes, even if the electricity was generated using a gas turbine. Running a gigantic engine at a constant RPM is always going to be more efficient than running a lot of small ones at variable RPMs. You'd have to lose a lot of energy over the wire to cause this to stop being true.

Your range will suffer due to heating the cabin though

[–] XeroxCool 4 points 8 months ago

Tuning for specific rpms is why the notoriously inefficient Mazda rotary engine is making a comeback in the hybrid as a generator.

[–] [email protected] 8 points 8 months ago* (last edited 8 months ago)

Which country is that? I live inn Norway. Remember that ICE cars burn gasoline to heat themselves, winter and summer. Less than half of the gasoline is used for movement.

Also, you don't have to preheat the car. The preheating is for the cabin.

[–] [email protected] 7 points 8 months ago

I was looking into buying an EV recently (northern europe), and the main drawback for me was the distance. ICE can get me 600-700 km onba full tank easy on a highway. Only few EVs can go reliably above 300 in cold weather (say -20C) - and those few cost like 2-3 times more than a brand new ICE. I mainly drive highways and usually over 300km in one go, for moving around the city public transport is good enough (or rental if you need to move large stuff).

[–] AA5B 7 points 8 months ago* (last edited 8 months ago)

There are plenty of people who remote start ICE vehicles as well.

I don’t know if it’s really warming the battery, but to warm the interior. By the time I get to my car, the cabin, seat, steering wheel are all at a comfortable temperature. The battery works regardless.

Preheating the cabin of an EV must be more efficient than using remote start on an ICE vehicle to pre-heat the cabin.

However for my case, I’ve never used remote start on an ICE vehicle, plus “fuel” for an EV feels so much cheaper and more plentiful and the control is better and I’m not generating air pollution, so I do. It’s probably changing my habits to be more wasteful in return for more comfort

Edit: when my battery is cold, the only difference I see is lack of regen: I have to use my brakes. While I know my battery will also charge slower and have lower capacity, that hasn’t impacted me yet

[–] Boinkage 5 points 8 months ago

More efficient per dollar or per energy unit? Either way, almost certainly EVs will be more efficient than a fossil fuel vehicle dollar for dollar or fuel energy unit.

[–] Sequentialsilence 4 points 8 months ago

In most cases yes, but it depends on the car for both EV and ICE. The few areas where ICE wins is when you’re running a super efficient hybrid, but those are few and far between, usually missing some nice luxury features like heated seats and automatically warming up your car before you get in. Things that are very nice for up north.

My sister who lives in Michigan can lose up to 50 miles of range when the weather drops, so she goes from 110 MPGe to around 70 MPGe when the temperature is below 0 (-18c). That’s still more efficient than most ICE but possible to beat.

[–] [email protected] 1 points 7 months ago

I don't know exactly, but from what I heard last winter, in a freak cold fronr in the states a some EVs completely died in the middle of their commute. I don't have a source just from my memory.