Electric cars question

almillar

But running any car in frosty/icy weather will require its heating to be run constantly - not just to de-ice the screen first thing in the morning
This will clearly decimate the range ?

I've run 2 EVs, over 4 years. No, it won't.


As I said, it runs hard (2kW, compare this to an 80kW motor!) at the start to get up to temp, then settles down. to a lower amount of energy.


Again, this energy is FAR LESS than the energy you're using to ACTUALLY DRIVE. It does not DECIMATE range.



You will go about two thirds as far in winter as you will in summer, in the UK. That's my general guide. So that's 66 miles if you did 100 in summer. That's not heating, that's battery chemistry.


Again, you can offset this with pre-heating, taking out the hardest part (the start) and heating whilst still plugged in.

MX5huggy

As said it’s all about air temperatures effecting battery performance not heating and lighting. The cars going to be using a kWh every 3 miles or so where as the heating is going to be less than 3kWh per hour. My i3 has heated seats they make no noticeable difference to range. The other thing is that it can be set to be preheated even if not plugged in.

ElefantEd

One of the (many!) nice things about our Leaf - and I imagine most other electric cars - is that being able to programme it to turn on the heating whilst plugged in at a time of your choosing means not having to scrape ice off the windscreen - our new one also warms up the seats and steering wheel (!).

uknick

AnotherJoe wrote: »

I"m going to disagree with that.
Yes in the past it was good advice to occasionally charge up to 100% to enable the batteries to be balanced but i think that is outdated advice now with much better battery management that does that anyway, you'll often see manufacturers recommend you charge to 80-85% only and on fast chargers theres usually an auto cut off at that point.
I believe ABC is there because of pragmatism, basically the charging network is still inadequate in many places (unless you have a Tesla) so grab a charge when you can.

Let's agree to differ then, The i3 definitely cell balances once the cells have charged to their allowable usable limit, about 90%. I can't speak for other brands, but the ABC idea is to get this balancing done.

It's nothing to do with ensuring you have a full charge in case you can't find a charger when out and about. Does cell balancing work to increase range? Can't say I've noticed any difference, but who am I to question the BMW engineers?

coffeehound

Is there a chance of Range Shock? E.g. Early morning, your car is all warmed up after overnighting in your cosy, undersized garage. The battery is nice and warm and showing a good range to get you to work and back.

Come 6pm, the car has been sat out in the wintry showers all day. The battery has chilled down and now lost x many miles of range and you haven't enough to get home.

DrEskimo

Well the garage would have to be heated to have such a large differential between the temperature in the garage and the temperature outside!

Around 10-15°C I rarely see much of a drop in range over the 'summer maximum'. Somewhere around 160ish out of a maximum 185 miles. It's only when temps hit 0 and below that I start seeing ranges fall below 140 miles.

So you would need a very warm garage that the battery stays around 15° in the morning, when temperatures are below 0° at 6pm! That's the only way you would see dramatic drops in range.

AnotherJoe

50Twuncle wrote: »

But running any car in frosty/icy weather will require its heating to be run constantly - not just to de-ice the screen first thing in the morning
This will clearly decimate the range ?

First of all, knocking somewhere between 2-8% isnt "decimating the range"
Second, loss of range is due to it being colder, not running the heater.
Third, as also explained, you can clear the screen / warm the car up whilst plugged in at home thus negating any loss of battery before you leave. (also, once the car is warm, it doesnt require as much energy to keep it warm)

AnotherJoe

coffeehound wrote: »

Is there a chance of Range Shock? E.g. Early morning, your car is all warmed up after overnighting in your cosy, undersized garage. The battery is nice and warm and showing a good range to get you to work and back.

Come 6pm, the car has been sat out in the wintry showers all day. The battery has chilled down and now lost x many miles of range and you haven't enough to get home.

You would plan for that. You'd know what the range was in the cold, what the distances were, what the range is.

So charge at home so you have enough to get there and back if you cant charge at work or dont want to charge on the way back.

Or, given cars with 200+ miles range even in winter, if your commute is 100+ miles each way, get a different job.

gzoom

50Twuncle wrote: »

But running any car in frosty/icy weather will require its heating to be run constantly - not just to de-ice the screen first thing in the morning
This will clearly decimate the range ?

In word No.

Here is the energy consumption of our EV for heating use with interior temperature set to 22.5 degrees and outside 3 degree.

The important figure is the top line, thermal controller is pulling 0.78KW to maintain temperature. For context our EV has a 6 seater interior with 70% of the roof space been glass - so neither a small car nor well insulated. It has a 65kWh usable battery, once up to temp the car can maintain 22.5 degrees with outside temp at 3 degrees for about 85hrs if assuming 100% charged.



For real life usage, this was a 110 mile trip on the M1 last weekend. 23 degrees interior temperature, started the trip with 75% charge, sat in stationary traffic for about 20 minutes at J14/15. Used about 60% battery for the trip. A 100%-0% trip in similar temperature/road conditions would be about 180 miles taking nearly 4hrs.....That is a long time to spend in a car in a UK winter without stopping!

coffeehound

^ Good grief, the loom on EVs must be hellish complex.

DrEskimo wrote: »

Well the garage would have to be heated to have such a large differential between the temperature in the garage and the temperature outside!

Around 10-15°C I rarely see much of a drop in range over the 'summer maximum'. Somewhere around 160ish out of a maximum 185 miles. It's only when temps hit 0 and below that I start seeing ranges fall below 140 miles.

So you would need a very warm garage that the battery stays around 15° in the morning, when temperatures are below 0° at 6pm! That's the only way you would see dramatic drops in range.

Interesting info, thanks. Does the battery not warm up overnight by the charging process?

AnotherJoe wrote: »

You would plan for that. You'd know what the range was in the cold, what the distances were, what the range is.

So charge at home so you have enough to get there and back if you cant charge at work or dont want to charge on the way back.

Or, given cars with 200+ miles range even in winter, if your commute is 100+ miles each way, get a different job.

Yes I was just throwing it out there as a possible though unlikely scenario, really. I suppose it's something the app or internet-enabled car could forecast.