Electric Vehicles

[Luckypants]

Originally Posted by Bibio

thanks for the info LP. thats pretty impressive. i looked at the price of the ID.4

wont be till next year i think about an EV and looks like it will be a Hyundai as the KONA looks just the ticket.

A good car, like it's sister the Kia e-Niro. Both very efficient. Those were just too small in the boot for us. Expect a long wait for a new one though.

[Luckypants]

For anyone considering an EV, things have changed with the Plug in Car Grant (PiCG) Reduced from £2500 to £1500 and price of eligible cars also reduced from £35K to £32K.

https://www.fleetnews.co.uk/news/lat...iteria-changed

[Bibio]

i would expect in the next 2 years or so to see all government grant schemes reduced or withdrawn.. we have to pay back furlough some way. its either that or raising tax/vat/duty (the gov must be making a fortune with import duty/customs/vat now though)

if they want to entice people to move over to EV then a whopping scrappage scheme for fossil fuel vehicles would be better.

[Luckypants]

Agree Bibio, although they are being quite aggressive in reducing the PiCG. This is the second reduction this year, the previous one was in March. Amazing how many car manufacturers were able to reduce prices to bring their cars under the threshold shortly afterwards though. It like the grant is keeping EV prices higher than they should be.

[Bibio]

another ? for LP.. yes yes i know.. lol

how is the charge to kwh calculated? lets say your ID.4 needs a 50% charge, how many kw is that.

[Luckypants]

Electric volume is measured in kilowatt hours (like your domestic meter). So battery capacity is given in kWh. My car has a 77kWh battery, which is the same as saying a petrol / diesel car has a 77 litre tank. The rate at which the electricity is put in is measured in kilowatts.

So 50% charge in my car is 38.5kWh.

The maths for kW to kWh is simple, just multiply the kW by time in hours.. A 1kW charger adds 1kWh of charge in an hour. A 2kW charger adds 2kWh of charge in an hour or 1kWh in 30 minutes. A 100kW charger can add 100kWh of charge in an hour, etc etc

How fast that charge is put in the car depends on two things.

1. The power of the charger. Public chargers advertise their power and basically the bigger the number the better.
2. The power the car can accept. The maximum DC charge my car can take is 125kW. The maximum AC charge it can accept is 11kW. Other cars can take differing amounts of power and it is one of the things to consider choosing a car, as this affects charge times.

Now the added complexity is that the charge rate a car can accept is not set in stone, it varies due to conditions.

In general, you will always get the maximum of either car limit or charge rate on AC chargers as these are low enough speeds to not be affected by other conditions. For me that is either 7kW at home / destination charges or 11kw (car limit) on fast AC chargers of 22kW or 43kW. Some cars can do 22kW on AC and early Renault Zoes can manage 45kW on AC.

DC charging is where the fun begins. My car has a headline charge rate of 125kW. Some cars can max at 200+kW. You only get this max charge rate when conditions allow. To get the best charge speeds you need

1. Your battery to be at a low state of charge. Typically below 10% As state of charge increases, the battery management system on the car will reduce DC power to prevent over heating or damage to the battery. See below for the charge curve for my car
   
   
2. Your battery to be warm, either by a long drive on the motorway or by pre-heating like Tesla / Mercedes / Audi / Porsche do automagically.
   
3. Local power supply to the charger is sufficient. Sometimes power is limited due to local demand.
   
4. No power sharing is taking place. Many chargers share a high power feed between them, so if two or more cars are charging, power to each car is reduced. This is how Tesla chargers work and information is easily found online. This is getting less common as operators realise the limitations as EVs become more common.

Probably raises more questions than answers.

[Bibio]

or lets say 140 miles for 50% of your charge which takes 38.5kwh to charge back up to full.

38.5kwh x £0.XXxx = £xx / 140 = cost of electricity per mile.

[Luckypants]

Again it varies....

If you have a smart meter, you will be able to get an EV tariff with low overnight prices or you may have economy-7 already. These tariffs can be as low as 5p/kWh giving costs as low as 1p per mile. So it depends on what you pay for your 'leccy. I cannot get a smart meter or economy-7 so my cost per kWh is 23p inc VAT. 38.5x23 = £8.85 to do 140 miles 6.33p/mile.

Public rapid chargers are more expensive, ranging from about 25p to 65p! per kWh. In Scotland some areas still offer free charging on Chargeplace Scotland chargers, but most council areas have now introduced prices for charging. EG free to charge in Hawick but Moffat charger is 25p/kWh. Gridserve who have a virtual monopoly on motorway service areas charge 30p/kWh. Instavolt charge 45p/kWh etc etc.

You can get free charges at various places, most commonly supermarkets. I charge regularly at Aldi and Tesco but have also used Asda's chargers. The free charges I get while shopping / getting lunch or whatever significantly improve my cost per mile. Over the approx 8.5K miles I've done my average cost per mile is 5.65p per mile. This is going up due to higher consumption in the winter with October average being 6.25 and November was 6.07.

[Bibio]

and in 10 years or even less it will be £1.50Kw at charge points and home charge points will be separate metered as the Gov will introduce a special duty. think of the revenue the Gov is going to loose. once gas has gone the gov will have us all over a barrel.

[Luckypants]

Originally Posted by Bibio

and in 10 years or even less it will be £1.50Kw at charge points and home charge points will be separate metered as the Gov will introduce a special duty. think of the revenue the Gov is going to loose. once gas has gone the gov will have us all over a barrel.

I think road use charging will be used to replace the lost revenue.