Comment by linsomniac | Hacker News Reader

Comment by linsomniac | Hacker News Reader

Range impact of cold weather does seem to be a real thing, I can't speak personally because I own a Tesla which has some of the lowest impact.

Another thing to keep in mind is: Charging speeds of cold temps. While the Tesla seems to do great at range, charging at cold temps is not great. When it's below freezing, home charging can be tough to impossible. A few days ago (when it was merely "cold", before the huge cold snap hit us), I drove the car and then parked it to charge for the night. It charged at a rate of 1 mile per hour. Usually it'll hit 30-40. I have it set to start charging at midnight, which meant that the battery cooled down after driving for ~6 hours, before it started charging. I could have started charging as soon as I got home, but then I'm in the 3x higher electricity pricing... I could bump that up to 9 or 10pm to help.

This also impacts road trips. If you are traveling in freezing temps, definitely charge before checking into a hotel (unless the hotel has a charger, which is fairly rare), rather than in the morning. Instead of 30m charge time, it can take 60-120 minutes to charge at a Supercharge.

These are all excellent points. If you navigate to a supercharger or a compatible fast dc charger in a Tesla, the vehicle will heat the battery pack appropriately for faster charging (based on max current capability at the charger). High level, this is a call for ubiquitous level 2 charging everywhere (and intelligent battery pack management when fast charging is available), with enough power to both charge the vehicle and keep the pack warm. We’re at the same stage with EVs as combustion vehicles were where you had to buy a can of petrol to fill it up, and gas stations weren’t ubiquitous. Make Charging Infra Ubiquitous.

Of course, within certain latitudes, more robust infrastructure is less necessary (the closer you get to the equator). Texas, Florida, and California have most of the US population and will rarely see these conditions (US centric).

Are you in a garage?

As long as you have 30+ amps of 240v, you are fine charging in winter. It will spend 5-15 minutes warning the pack (and show only a little charge rate) and then kick into your full charge rate.

The only time you are screwed is in like 15-20 amp 120V, it takes nearly all the power to keep the battery warm so almost nothing left to charge. If it weren’t for winter I likely would have kept only a 120 in my garage as that is plenty for summer charging at home.

Same was true (symmetrically more it less) at summer temps north of Phoenix: all the power went to cool the battery leaving nearly uselessly slow recharge times.

I'm not in a garage, good point.

> When it's below freezing, home charging can be tough to impossible.

Don't mix up "home charging" with "level 1 charging". A lot of EV owners will get a NEMA 14-50 receptacle to level 2 charge, and then there's no problem at all charging while below freezing.

To clarify, I'm talking NEMA 14-50, 240V@50A breaker, 40A charger) and will regularly get low charging rates if it's very cold.

I have that exact setup and haven't had that experience.

Charging in a garage or outside when it's 15F or below?

Outside, with the temperature in the single digits.

It’s strange that people’s experiences are so varied with EVs in cold weather. Here it’s 14F right now and my Model Y is charging at 30 mph (versus 32 mph in warm weather). Driving 120 miles this morning at 11F used maybe 10% more energy than normal. The doors, though, we’re quite sticky and frustrating to open.

Is that the temp where the car is? (garage?)

How long did the battery sit in 14F after driving 120 miles? If I charge right after a 120 mile trip, that'd be fine. Also, are you saying the car is in 14F, or it is 14F outside and your car is in the garage? My car is outside (I use my garage as a shop).

I park outside. My garage is also a shop. I guess that I didn’t let the car soak in the cold snap, last week; I usually plug it in when I get home, since this is more convenient for me.

The Model Y has a heat pump, that helps a lot.

That being said I’ve not noticed charging issues with my Model 3, this is my 3rd winter, last week we regularly had -7 C in the night. Does seem to be a lot of variability

> I own a Tesla which has some of the lowest impact.

I have a suspicioun those cars that seem to have no impact on range due to temperature just increase the deepth of discharge in colder weather.

I.e. Tesla and Jaguar.

No, it’s because they tend to pull energy from the charger to warm the battery. They’re also often parked indoors. And if you buy one in a cold climate, you’ll often be getting a winter package which includes a heat pump, reducing energy needed for heating the cabin and the battery by a factor of 2 to 3.

if you garage the car it should be ok. I'm outside of Denver and this latest cold spell at night was -22 and my garage temp sensor was 52.

Ya EVs aren't fun in cold areas if you don't have a garage or on a road trip

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