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Discussion Starter · #1 ·
I've been researching the Leaf for a while and see lots and lots of ads proclaiming that the Leaf only costs 2p per mile but I can't quite see how they calculate this.

OK, so I am in Malta and our costs might be slightly different - but a KWhr here costs €0.12 and if the Leaf capacity is 24KWHr then it's going to take 30 KWHr to fully charge it assuming normal charger efficiency.

So that's €3.60 in electricity to cover 80 miles. That makes it 4.5c per mile - or in UK terms 3.5p.

To make it 2p per mile the UK electricity price would have to be 5.3p per KWHr and I have a feeling that you are paying more than that?

Don't get me wrong - I'd still have a Leaf if it was 20p a mile because of all the other benefits LOL
 

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Discussion Starter · #4 ·
Charger efficiency is about 95% and Li-Ion charging is between 85-90% efficient.

OK on the use of the capacity - I'll have to put a KWHr meter on the slow charger when the Leaf arrives and see exactly how many KWHr it uses to charge at each SOC - just for fun of course :)
 

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I think Malta has a reasonable EV charging infrastructure doesn't it? I was reading an article about it a few weeks ago.

Useable charging capacity on a 24kWh Leaf is about 21kWh and depending on the roads and how you drive you could get 80-90 miles from that. UK Economy 7 costs are 5-7p/kWh (we pay 6p with Ecotricity) but most people would use 10-15% for the charging losses, not 25% which sounds exceptionally poor.

So, 21kWh x 6p x 1.15 per 80 miles say = £0.018/mile = 2p/mile
 

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I work mine out simply by using month by month data (from the meter supplying my charge point and the mileage of the car).

Data for The month of Feb is as follows.

1st March - meter Redding: 2169.92 (month before was 1867.94)

Travelled 862 miles

costing £24.76 in electricity at just over 8ppkw. (Sainsburys energy, fixed until Dec).

So it's Costing around £0.03 per mile.

I hope I've done my maths right, bit hard doing it all on my iPhone at the same time.
 

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I'm taking an empirical rather than theoretical approach. I log every charge including kWh hours consumed and the actual cost of charging. Taking into account free charges away from home and subtracting £40 from my home charging cost (courtesy of the Ecotricity EV car discount) so far in 5 months I have driven 4641 miles at a total cost of £31.88 which is 1p/mile!
 

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Ioniq Project 45, e-Niro4+
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We calculate our costs when we do a 100% charge, (so only occasionally!), and do the maths from the miles covered, the metered power consumed from the 'big brother box' at the charge unit, and our price of 10.78 pence per unit. We average about 3p per mile in summer, and 3.5p in colder weather. This is fairly accurate as we rarely top up elsewhere.
Assuming you do not play the 'traffic light' grand prix, and take it easy on the hills @SteveMalta , you should be fine, given your climate....... and use aircon judiciously!!
 

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It is a simple computation with just 3 parameters: the distance you can travel for 1kWh, the charging efficiency, and the price you pay for a kWh. I just have my Leaf for a week so my experience is limited, but it indicates that for short trips (no motorway) I can do about 7km on average for a kWh (that's 14.2 kWh per 100km as the car indicates average consumption), which is about 4.35 miles (but your mileage may vary). According to other messages here, charging efficiency could be about 85%, so multiplying that I'd get some 3.7 miles per kWh I pay for. Taking your €0.12 as price per kWh which is about 9.3 pence, divide by those 3.7 miles per kWh to get about 2.5 pence per mile. Indeed I cannot quite make this 2p with reasonable assumptions, unless you can occasionally charge for free (here in France, most public charging is free for now).
 

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It is a simple computation with just 3 parameters: the distance you can travel for 1kWh, the charging efficiency, and the price you pay for a kWh. I just have my Leaf for a week so my experience is limited, but it indicates that for short trips (no motorway) I can do about 7km on average for a kWh (that's 14.2 kWh per 100km as the car indicates average consumption), which is about 4.35 miles (but your mileage may vary). According to other messages here, charging efficiency could be about 85%, so multiplying that I'd get some 3.7 miles per kWh I pay for. Taking your €0.12 as price per kWh which is about 9.3 pence, divide by those 3.7 miles per kWh to get about 2.5 pence per mile. Indeed I cannot quite make this 2p with reasonable assumptions, unless you can occasionally charge for free (here in France, most public charging is free for now).
Nissan's figures to get down to 2p a mile assume use of a UK Economy 7 tariff which gives a cheap night time rate and a more expensive than average day time rate and that you do your vehicle charging during the night time rate period. Economy 7 was designed for domestic use with night storage heaters. Unless the cheap rate usage is about 3x the daytime usage, it does not generate an overall saving. In the UK about 71% (kWh) of all EV charging is done at home.

My own usage on a 12p per kWh tariff works out at 2.5p a mile based on consumption metered before the wall charger.
 

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Does it really take 125% to charge each kW/h?

Also bear in mind you don't charge/use the full 24 kW, probably more like 18 or 19 for a full 'tank'
Best estimate a 'full tank' that transfers for useful work is 19.7 kWh with a battery in good condition. Assume about a 8% loss on charging and another 8% on discharging the battery, so just under 23 kWh at the electricity meter needed to charge the battery from 0 to 100% as it is presented to the driver. Car Wings often records a slightly different percentage of charge to that displayed in the car which might be based on the actual percentage of the total battery rather than that which the driver can draw upon.
 

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My measurements indicate that I need to put in 108% of the kWh into the battery to get 100% stored. In other words there
is an 8% overhead in charging losses.
My Economy 7 rate is 4.16p/kWh, and I normally manage 4 miles/kWh driven.
Hence every kWh in my battery has cost me 4.49p to put in there, and I get 4 miles for that 4.49p = 1.12p/mile. YMMV.
 

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Discussion Starter · #16 ·
Assuming you do not play the 'traffic light' grand prix, and take it easy on the hills @SteveMalta , you should be fine, given your climate....... and use aircon judiciously!!
3.5p sounds more realistic than the 2p the dealers are all quoting for sure!

I can see the ac getting a good work out in July/August here. I've spent the last 2 nights reading the pdf User Manual It is more complicated than trying to get to grips with an iPhone 6. I bet that most owners do not know half the things that it can do. I mean hands up who can tell me (without looking at the manual, how to change the windscreen wipers?

I have to say that as I was reading all the pages of warnings and things to do during cold and freezing weather, I was sitting there flipping the pages saying "Nope, not interested in that" LOL
 

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Well dont expect any sympathy from UK users on this forum if you start complaining that using the climate control drops your range by 5 or 6 miles! We loose that trying to warm ours up and pushing rain water out of the way!
 

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Last time I check my cost per mile, I used the figures that OLEV were being sent from my Polar chargepoint.

I worked out how much it was costing me based on my tarrif. Then the miles I had driven over that period and it came out to 2.7p/mile.

However, I have not taken into consideration any rapid charging, as I currently don't have to pay for it. My rapid use is currently about 10% of my L1/L2 charges.

Cost per mile
 

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Discussion Starter · #20 ·
Mike, that makes your economy around 5.8mile/KWHr average which is pretty exceptional so when you take into account your free Rapids then the real p/mile must be higher as it would be even worse if the dealers were saying you can get 2p per mile IF you charge up 50% of the time on free electricity :)
 
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