A few questions on EV's

[Evanivitch]

Heres Johnny said:

jamoor said:

That's another thing, driving an EV you can chuck fuel economy out the window.

If your car does 30mpg and you do 100 miles, it has cost you £19.70

If driving with no regard for economy causes you to use 25% more fuel it will cost you £24.65 for the same journey, extrapolate that over 10k its an additional £500 a year.

For an electric car.. it will cost you £4 for 100 miles. if we add 25% more electricity to that we are looking at £5. Extrapolate that over 10k then its £400 to £500, which is £100 more. The numbers involved are alot smaller.

All very well but you might want to drive economically so you can actually get home and charge with minimum inconvenience.

Sure, I don't really think of economy on a short trip, I never have really, but if you've 200 miles to go you might manage it a bit more carefully.

Exactly. Hypermiling on EVs is much more about miles range than MPG!


OP, make sure you come back to the thread with any controversial nuggets of info. I can't wait to hear what some of the EV driving T3s are spouting.

[jamoor]

Just stop for a quick 10mins charge if you’re running out. Same applies for petrol cars, you will run out quicker

[Heres Johnny]

Max_Torque said:

Once you get to temperature below around 3degC (or above around 35 degC) then yes, there is an additional battery conditioning requirement, that CONSUMES more energy (although thanks to the low specific heat and thermal impedance of batteries that energy is actually fairly small) but an EV powertrain gets MORE efficient the colder it is, because the resistance of the conductors falls with temperature!

For a short journey where you clearly don't need much range, then there is no need to heat the battery to the point where max SoC is realised, further minimising consumption.

The reduced resistance of conductors when cold is pretty marginal in the range we’re talking so to talk about more efficient power train is a little misleading as that’s ignoring the battery which is the elephant in the room. The internal resistance of the battery is significant when cold reducing the efficiency - the heat produces internally warms the battery which is why some EVs don’t bother with battery heaters. I’d take a car at 20 deg c over one at even 10 deg c every time. And 75k miles of driving an EV seems to correlate. The very worst journey in an EV for efficiency is a short one when the battery is colder than its optimum temperature (which I believe is around 24-28 deg c) and the further below the worse the efficiency.

[ZesPak]

One more thing RE the charging speed. It is often expressed as the amount of energy put in the car, but it's a lot more useful in terms of "miles/h".

I don't know in a leaf, but in my Model S:
Level 1 ("granny charging" in a regular outlet) = 15km/h
Level 2 (most public parking chargers /one you install at home) = 65km/h
Level 3 ("Supercharging") = 600km/h

It's not always that accurate but gives a good idea in terms of how long you have to charge. For example : if you drive 75km/day, it would take you ~5h to charge that in a regular plug.

[manracer]

Max_Torque said:

manracer said:

You sure about the above?

Cold EV power train consumes much more energy!

Short journeys are a massive penalty, and the colder the power train the biggest the penalty.

Consumption is also affected by effective use of Regan, so coaching of all this plus more will have a massive impact on consumption.

Surely you know all this?

Once you get to temperature below around 3degC (or above around 35 degC) then yes, there is an additional battery conditioning requirement, that CONSUMES more energy (although thanks to the low specific heat and thermal impedance of batteries that energy is actually fairly small) but an EV powertrain gets MORE efficient the colder it is, because the resistance of the conductors falls with temperature!

For a short journey where you clearly don't need much range, then there is no need to heat the battery to the point where max SoC is realised, further minimising consumption.

I'm my experience with my model 3 I completely disagree. I find that it's about 6 degrees or below when consumption increase.

Short journeys (less than say 15 miles) + below 6 degree temp increase the consumption 2 fold.

[jamoor]

ZesPak said:

One more thing RE the charging speed. It is often expressed as the amount of energy put in the car, but it's a lot more useful in terms of "miles/h".

I don't know in a leaf, but in my Model S:
Level 1 ("granny charging" in a regular outlet) = 15km/h
Level 2 (most public parking chargers /one you install at home) = 65km/h
Level 3 ("Supercharging") = 600km/h

It's not always that accurate but gives a good idea in terms of how long you have to charge. For example : if you drive 75km/day, it would take you ~5h to charge that in a regular plug.

You missed out the 50kw 200m/h which aren’t exactly uncommon.

[ZesPak]

Oh, haven't seen those really tbh.
Where are they used? Almost all commercial ones I've encountered or can see on the map are 11kW 60km/h.

[SWoll]

ZesPak said:

Oh, haven't seen those really tbh.
Where are they used? Almost all commercial ones I've encountered or can see on the map are 11kW 60km/h.

Quite a few around. Just been and charged our Model 3 P at a Polar 50kw charger which is located in our local Waitrose car park. Averaged about 45kw from 30-95% and then dropped to 10kw.

Watched the last 90 minutes of The Irishman on Netflix whilst I was there and left with 98% charge and 305 miles predicted range.

[Evanivitch]

ZesPak said:

One more thing RE the charging speed. It is often expressed as the amount of energy put in the car, but it's a lot more useful in terms of "miles/h".

I don't know in a leaf, but in my Model S:
Level 1 ("granny charging" in a regular outlet) = 15km/h
Level 2 (most public parking chargers /one you install at home) = 65km/h
Level 3 ("Supercharging") = 600km/h

It's not always that accurate but gives a good idea in terms of how long you have to charge. For example : if you drive 75km/day, it would take you ~5h to charge that in a regular plug.

Does a anyone use "levels" of charging in the UK? Slow (2-3kW), Fast (7-22kW), Rapid (50-100kw) and Ultra (120kW-250kW) are the usual terms I understand.

Also, using he actual power rating and charge time is really simple for kWh. And really can't be hard for the person on the street to understand how many kWh get them X miles.

[RobDickinson]

Evanivitch said:

Does a anyone use "levels" of charging in the UK? Slow (2-3kW), Fast (7-22kW), Rapid (50-100kw) and Ultra (120kW-250kW) are the usual terms I understand.

Not really - as "level 1" is 120v , "level 2" is 240v charging and "level 3" is DC/fast charging.

So really only useful in USA where they have 120v mains.

[RobDickinson]

watchnut said:

shows how ignorant you are, I came on here to ask a few questions BEFORE I did the training so once trained i can then train stupid people like yourself

ignore the trolls, plenty of them in here sadly.

[jamoor]

ZesPak said:

Oh, haven't seen those really tbh.
Where are they used? Almost all commercial ones I've encountered or can see on the map are 11kW 60km/h.

I usually filter by min 40kwh. I wouldn’t bother with anything less unless it’s a destination charging thing.

[SWoll]

jamoor said:

ZesPak said:

Oh, haven't seen those really tbh.
Where are they used? Almost all commercial ones I've encountered or can see on the map are 11kW 60km/h.

I usually filter by min 40kwh. I wouldn’t bother with anything less unless it’s a destination charging thing.

Anything below 50kW is basically useless for en-route charging. Just too slow.

[manracer]

SWoll said:

jamoor said:

ZesPak said:

Oh, haven't seen those really tbh.
Where are they used? Almost all commercial ones I've encountered or can see on the map are 11kW 60km/h.

I usually filter by min 40kwh. I wouldn’t bother with anything less unless it’s a destination charging thing.

Anything below 50kW is basically useless for en-route charging. Just too slow.

I guess that depends on your SoC when you arrive at the charger and how far you have left to travel on your journey.

I was getting 40kw at a charger just yesterday, it added about 100 miles in 30 minutes which was more than enough in terms of range and speed

[SWoll]

manracer said:

SWoll said:

jamoor said:

ZesPak said:

Oh, haven't seen those really tbh.
Where are they used? Almost all commercial ones I've encountered or can see on the map are 11kW 60km/h.

I usually filter by min 40kwh. I wouldn’t bother with anything less unless it’s a destination charging thing.

Anything below 50kW is basically useless for en-route charging. Just too slow.

I guess that depends on your SoC when you arrive at the charger and how far you have left to travel on your journey.

I was getting 40kw at a charger just yesterday, it added about 100 miles in 30 minutes which was more than enough in terms of range and speed

As above that would likely be a 50kW then, I've not seen better than about 45 kW on ours so far which is as slow as I'd be willing to wait for if not parking up with something else to do for a few hours.

[NDNDNDND]

SWoll said:

Quite a few around. Just been and charged our Model 3 P at a Polar 50kw charger which is located in our local Waitrose car park. Averaged about 45kw from 30-95% and then dropped to 10kw.

Watched the last 90 minutes of The Irishman on Netflix whilst I was there and left with 98% charge and 305 miles predicted range.

You sat in your car, on your own, for an hour and a half in a supermarket car park, watching Netflix?

Sounds like an episode of Black Mirror...

[SWoll]

NDNDNDND said:

SWoll said:

Quite a few around. Just been and charged our Model 3 P at a Polar 50kw charger which is located in our local Waitrose car park. Averaged about 45kw from 30-95% and then dropped to 10kw.

Watched the last 90 minutes of The Irishman on Netflix whilst I was there and left with 98% charge and 305 miles predicted range.

You sat in your car, on your own, for an hour and a half in a supermarket car park, watching Netflix?

Sounds like an episode of Black Mirror...

It was warm, comfortable, had a mug of tea and some biscuits with me and saved me about £10 on charging at home or £50 on fuelling an ICE car for the same range. The supermarket was closed anyway so the car park was empty.

When you've got teenagers in the house getting an hour and a half to yourself whilst saving money is a blessing and was planning on watching the same film whilst the wife and kids watched the I'm a Celebrity final anyway.

Don't knock it till you've tried it, was bliss.

The 5 minute drive home an a quiet Sunday night with 95%+ battery (so full power output) was rather fun as well.

Edited by SWoll on Monday 9th December 11:54

[Heres Johnny]

I believe the 50kw is based on 400v and 125a - and I believe the M3 has a lower voltage hence why you’re unlikely to see 50kw

[Dave Hedgehog]

Heres Johnny said:

I believe the 50kw is based on 400v and 125a - and I believe the M3 has a lower voltage hence why you’re unlikely to see 50kw

M3 can peak charge at 250KW and sustain charge at 125KW

[Evanivitch]

Dave Hedgehog said:

Heres Johnny said:

I believe the 50kw is based on 400v and 125a - and I believe the M3 has a lower voltage hence why you’re unlikely to see 50kw

M3 can peak charge at 250KW and sustain charge at 125KW

Of course, but if the charger is limited to 400V and 125A, and the car limited to 350V, then the charger probably isn't going to provide the additional current to allow 50kW charging.