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Given you can get 80% charge in an hour or less on most of the new ones I don't see the issue. Unless you are using a 3 pin plug over night charging will not be thing. Even on the lower powered charging points you are talking a max of 6 hours so unless you are planning on burning the candle at both ends it'll be fine.

It's worth watching the fully charged series on you tube, even if you aren't looking to buy one it's interesting to see where the tech is. Even relatively ordinary electric cars are nudging 150 mile real world range now.
 
StevenRB45 said:
Given you can get 80% charge in an hour or less on most of the new ones I don't see the issue. Unless you are using a 3 pin plug over night charging will not be thing. Even on the lower powered charging points you are talking a max of 6 hours so unless you are planning on burning the candle at both ends it'll be fine.

It's worth watching the fully charged series on you tube, even if you aren't looking to buy one it's interesting to see where the tech is. Even relatively ordinary electric cars are nudging 150 mile real world range now.
Click to expand...


Hi,
Not on a domestic charger. Even a small battery like a Leaf needs more than an hour. You can't change the physics 40kWh x .8 = 32kWh For a 1H charge at 230V that's 140A without allowing for charger and charging efficiency. Highest domestic feed is 100A, many are 60A so can't do it in an hour on any domestic supply. The high power chargers use a 32A outlet (specially installed) so that's 32Ax230V = 7.36kWh call it 7kWh with 95% charger/charging efficiency so a 80% charge on a 40kWh Leaf will take just over 4.5 hours with a high power charger (32/7). With a 13A outlet it will take 11.5 hours. Not sure were you get "less than an hour" and "a max of 6 hours from". It's about 20 minutes charging on a 32A outlet for every 10 miles on a Leaf assuming a 150 mile range on 40kWH.


Robert G8RPI
 
g8rpi said:
Hi,
Not on a domestic charger. Even a small battery like a Leaf needs more than an hour. You can't change the physics 40kWh x .8 = 32kWh For a 1H charge at 230V that's 140A without allowing for charger and charging efficiency. Highest domestic feed is 100A, many are 60A so can't do it in an hour on any domestic supply. The high power chargers use a 32A outlet (specially installed) so that's 32Ax230V = 7.36kWh call it 7kWh with 95% charger/charging efficiency so a 80% charge on a 40kWh Leaf will take just over 4.5 hours with a high power charger (32/7). With a 13A outlet it will take 11.5 hours. Not sure were you get "less than an hour" and "a max of 6 hours from". It's about 20 minutes charging on a 32A outlet for every 10 miles on a Leaf assuming a 150 mile range on 40kWH.


Robert G8RPI
Click to expand...

Couple of things first of all you are assuming the battery starts at 0..which no electric car will allow for battery preservation reasons and second your figures for a 7 kWh charger are worse what the industry quotes for a 3.5 kWh charger
 
Robert is correct with the physics. Any further discussion demands reference back to the exact use case. A quick Google indicates that there are people saying that they have a 30 kW Leaf... Am guessing that is the actual allowance from full to empty based on how they quote the charge discharge readings on their cars. So 80% charge of 30kwhr is just over half a 40kwhr full charge. And so on. In any event think there is plenty of time and capacity to pop out for a takeaway and charge for the morning.... ☺️
 
StevenRB45 said:
Couple of things first of all you are assuming the battery starts at 0..which no electric car will allow for battery preservation reasons and second your figures for a 7 kWh charger are worse what the industry quotes for a 3.5 kWh charger
Click to expand...

Hi,
The statement I was replying to said "you can get 80% charge in an hour or less" so I took 80% of the (Googled) 40kWh Leaf capacity. That could be 10% to 90% or whatever. 40kWh is the latest specification. early models had just over 21kWh usable so the times would be about half, still over two hours though.
I may have been pessimistic with my charge time per mile as I used 150 mile range and Nissan claim "up to" 235 miles for the 40kWh Visia version. This is still 40/235 = 0.17kW per mile or 1.7kW for my 10 mile example. with a 32A / 230V input 95% efficient charger giving 7kW this is still 14 minutes charging per 10 miles (1.7kW x 10 miles / 7kWh = 0.243h x 60 = 14.6m)
Note the original comment did not specify a Leaf, I chose it as a good example, a 100kWh Tesla S would be much worse.
What 7kWh charge figures are you referring to?




Robert G8RPI.
 
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g8rpi said:
Hi,
The statement I was replying to said "you can get 80% charge in an hour or less" so I took 80% of the (Googled) 40kWh Leaf capacity. That could be 10% to 90% or whatever. 40kWh is the latest specification. early models had just over 21kWh usable so the times would be about half, still over two hours though.
I may have been pessimistic with my charge time per mile as I used 150 mile range and Nissan claim "up to" 235 miles for the 40kWh Visia version. This is still 40/235 = 0.17kW per mile or 1.7kW for my 10 mile example. with a 32A / 230V input 95% efficient charger giving 7kW this is still 14 minutes charging per 10 miles (1.7kW x 10 miles / 7kWh = 0.243h x 60 = 14.6m)
Note the original comment did not specify a Leaf, I chose it as a good example, a 100kWh Tesla S would be much worse.
What 7kWh charge figures are you referring to?




Robert G8RPI.
Click to expand...

I'm going to be honest and say I probably wasn't entirely awake when I made the 7kwh comment..god knows.

I've mainly been playing around with this https://leccy.net

You won't have a 3 phase charger at your home address but you can certainly plan one into your route. Also the leaf has previously had a fast charge capability and continues to offer that in the new model which allows 80% charge in 40 minutes off the correct power source.

Main point was though unless you are charging off a 2.3kw domestic socket charging all night is not required.
 
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Hmm,
Leccy.net says 53 minutes for 70% charge increase (10% to 80%) on a 2018 40kWh Leaf with a 50kWh supercharger. This indicates about 80% total charge efficency which is about right.
Just for background, I used to design and build battery capacity testers (and chargers) for aircraft batteries as a sideline. These only went to about 1.5kWh but are used for mandatory capacity tests carried out every 6 or 12 months. So I'm qualified to talk about battery capacity calculations ;).

Robert G8RPI
 
g8rpi said:
Note the original comment did not specify a Leaf, I chose it as a good example, a 100kWh Tesla S would be much worse.
Click to expand...

Tesla do have the option of a 16.5KW home charger if the power supply to the house allows it. Which means a full 100kw charge in around 6 - 7hrs

The Leaf has the option of a home fast charger 7kw charger full charge in around 7.5 hrs

The concern about going out one night and charging overnight and then going out again with a full battery the next morning, are not a concern. As it is possible to reasonably charge these cars to full over night on a home charging unit. Probably not with an extension lead and a 13amp plug though.
 
Hi,
A 16.5kW charger would require a 72 amp supply at 230V single phase. This is not practical on a UK domestic supply which is either 60A or 100A single phase. Getting a 230/400V 3 phase supply in a house is expensive and may not be authorised if local substaion loading is high. Even a 32A single phase outlet should not be installed if the house already has a 40A electric shower feed and an electric cooker. The current (pardon the pun) UK infrastructure is not up to every 3rd or 4th house having an extra 32A / 20kWh demand in the evening. On mainland europe a 3 phase supply to domestic premises is more common so they can support the larger chargers. There is another issue that the electronics to use a single phase at high power is more difficult as the ripple frequency is 3 (or 6) times lower.

Robert G8RPI.
 
g8rpi said:
Hi,
A 16.5kW charger would require a 72 amp supply at 230V single phase. This is not practical on a UK domestic supply which is either 60A or 100A single phase.
Click to expand...

I’m perfectly capable of doing some simple maths. Please do your research though before coming back and quoting a load of irrelevant numbers.

Tesla will do a 7.4kw charger on a standard domestic single phase supply, 11kw on a standard 3 phase connection and up to 16.5kw on an upgraded 3phase connection

These do come at a cost, something in the region of £2k-£10k to have installed depending on the supplies in the area and the Tesla charger is about £500. New build areas already have installed supplies that are much better than in older or more rural areas. Live near any large commercial or industrial units and you’re guaranteed to have a local grid that can cope with the upgrade.

Most Model S owners abuse their super charger allowance at 120Kw charging capacity. These stations are capable of 145KW charging, at the moment however the cars are not, I suspect the 200KW battery in the new Tesla Roadster, will be capable of much faster charging. The Leaf is capable of much more powerful and speedy recharges with the right equipment installed, I’d not be supprised if a company somewhere will install a home fast charger on a 3 phase system
 
AndyRKett said:
I’d not be supprised if a company somewhere will install a home fast charger on a 3 phase system
Click to expand...

Pod point do a 22kw home charger (provided your local infrastructure supports) for 1k installed taking into account 500 quid government grant. Not quite the full 50kw beast that you get in public places but should be more than enough to charge a 40kw leaf pretty damn quickly.
 
AndyRKett said:
I’m perfectly capable of doing some simple maths. Please do your research though before coming back and quoting a load of irrelevant numbers.

What irrelevant numbers?


Tesla will do a 7.4kw charger on a standard domestic single phase supply, 11kw on a standard 3 phase connection and up to 16.5kw on an upgraded 3phase connection


What I said, you can't have a 16kW charger on a UK domestic supply What is a "standard" 3 phase connection? if you mean 60/100A then that's the standard supply for 3 houses!

These do come at a cost, something in the region of £2k-£10k to have installed depending on the supplies in the area and the Tesla charger is about £500. New build areas already have installed supplies that are much better than in older or more rural areas. Live near any large commercial or industrial units and you’re guaranteed to have a local grid that can cope with the upgrade.


You are not guaranteed a higher supply near industrial units, while things have got better with more efficient machines, I have direct experience of a company not being able to get the power they needed without a substantial contribution to a new substation.

Most Model S owners abuse their super charger allowance at 120Kw charging capacity. These stations are capable of 145KW charging, at the moment however the cars are not, I suspect the 200KW battery in the new Tesla Roadster, will be capable of much faster charging. The Leaf is capable of much more powerful and speedy recharges with the right equipment installed, I’d not be supprised if a company somewhere will install a home fast charger on a 3 phase system
Click to expand...


Don't get me wrong, I'm pro EVs I've followed developments since the seventies when Sodium-Sulphur was the big thing in new battery technology. What frustrates me is the rose-tinted and blinkered view the industry has toward charge times and infrastructure. I was at a motorway service station recently and it had about 15 charging stations out of hundreds of spaces. Even the 15 is a quarter of a megawatt if fully used. What are we going to do when there hundreds of cars wanting to charge while drivers eat? The infrastructure will come but I see no coherent policy or plan at the moment.

Robert G8RPI
 
I think it's important we do our own research and we are well informed. It seems that the range prediction on these things are just as, if not more, optimistic than those on ICE cars...

https://www.chroniclelive.co.uk/news/north-east-news/nissan-leaf-owning-mp-tells-14219479

But we've been driving ICE cars for years - most people know what to expect from their car in terms of range from a glance at the fuel gauge. It's going to take us time to understand how range works on EVs and be prepared to be towed if you're going to try to sail close to the wind!
 
Irrelevant numbers relate to posting comments on what you would and wouldn’t need for a 16.5kw connection, when if you’d bothered to look it up, you’d have seen its a 3 phase connection and so your maths was pointless and not in anyway applicable.



You can have a 16kw charger in your home, you can easily pay to have the additional work done to install a 3 phase charger in your home. Every house is plugged into the three phase system, they just come off a different phase for different house in the street. It’s not one three phase supply for 3 houses, Chances are that most of the houses on one side of the street will be on the same phase. It’s the connection going into the house that is rated at 100A due to the diameter of the conductors going into the building. The power grid is capable of supplying far more and there is wiring in every area corner of the country for 3 phase wiring the problem comes the further you are away from the other phases and the work that is needed to connect you.

I have plenty of ‘direct experience’ of working with these things. I used to build and work on power meters for industrial companies.

If you want to build a factory or company that requires loads of machines, and the local area can only support domestic levels of plugged in equipment, then of course a company is going to have to pay towards updating the local substation.

My brother has 3 phase in his unit (doesn’t use it though) my father in law has 3 phase in his unit and has a few machines plugged into this.
My father has a 16amp connection, single phase in his garage for his specialist welding plant.

Anything is possible if you are willing to pay your money.

As far as the network is concerned, having everyone charging their cars on 3phase is a dream, keeps the phases equal, no correction needed, no stress on the network if everyone on one side of the street plugs in while everyone on the other side goes out. If one phase goes down everyone is affected so it doesn’t.

This is why the network is opening up access to the high KVA lines for charging points and stations like the super chargers.

I’d expect over time everyone with a home charger will be moved over to a 3 phase system.
 
There is a tremendous lack of infrastructure in many areas and there is no co-ordinated approach. On balance there are far fewer areas with sufficient supply than we might wish. The last mile is always the most expensive it will cost a fortune to rewire many houses to 3 phase even if the sub station capacity allow. Even new buildings are not yet required to allow for this. Smart metering uses today's technology and even they are a shambles. Future charging systems will have to be standardised across all brands of car. They will have to be networked to every significant house to manage demand at least as far as the local sub stations. In effect they will have to schedule and ration charge rate, and feed in, to allow for necessary unscheduled demands such as showers, or tea making during a national event interval. To those of us debating the technology these things are just a matter of patience and know how. Trouble is, politicians are behind this... And car manufacturers are not compelled to do it either. There should be a building code for this already and developers, charge suppliers, final customers and so on should not get any help to buy or subsidy until they all line up, think about long term viable options, and comply. And yes, the solution for one street or area, even house, might have to differ to another depending on local conditions, as all building codes allow anyway. It will in every way cost a fortune.
 
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AndyRKett said:
Irrelevant numbers relate to posting comments on what you would and wouldn’t need for a 16.5kw connection, when if you’d bothered to look it up, you’d have seen its a 3 phase connection and so your maths was pointless and not in anyway applicable.



You can have a 16kw charger in your home, you can easily pay to have the additional work done to install a 3 phase charger in your home. Every house is plugged into the three phase system, they just come off a different phase for different house in the street. It’s not one three phase supply for 3 houses, Chances are that most of the houses on one side of the street will be on the same phase. It’s the connection going into the house that is rated at 100A due to the diameter of the conductors going into the building. The power grid is capable of supplying far more and there is wiring in every area corner of the country for 3 phase wiring the problem comes the further you are away from the other phases and the work that is needed to connect you.

I have plenty of ‘direct experience’ of working with these things. I used to build and work on power meters for industrial companies.

If you want to build a factory or company that requires loads of machines, and the local area can only support domestic levels of plugged in equipment, then of course a company is going to have to pay towards updating the local substation.

My brother has 3 phase in his unit (doesn’t use it though) my father in law has 3 phase in his unit and has a few machines plugged into this.
My father has a 16amp connection, single phase in his garage for his specialist welding plant.

Anything is possible if you are willing to pay your money.

As far as the network is concerned, having everyone charging their cars on 3phase is a dream, keeps the phases equal, no correction needed, no stress on the network if everyone on one side of the street plugs in while everyone on the other side goes out. If one phase goes down everyone is affected so it doesn’t.

This is why the network is opening up access to the high KVA lines for charging points and stations like the super chargers.

I’d expect over time everyone with a home charger will be moved over to a 3 phase system.
Click to expand...

Sorry Andy you are completely wrong apart from "Anything is possible if you are willing to pay your money.". Every house is NOT "Plugged into the 3 phase system" and every house one the same side of the street is not on the same phase. The 3 phase feeder runs down the street and each house has a single phase cable tapped into it, every third house on the same phase. They do not waste metal feeding two unused phases to each house. On modern systems they don't even have seperate neutral and earth conductors, the use the sheath/armour for both. Yes industrial unirs have 3 phase supplies houses don't. To get 3 a 3 pase supply involves digging up the road, trenching (or blind boring) from there to the house and installing a new 3 phase cable. Not a cheap job. The company I knew that had to pay for a substation was in a fairly modern (1970's) industrial estate, no housing at all. Still no nswer on how they will supply hundreds of charging stations at motorway services. A conservative number for the near future would be 50 80kW and 20 120kW (Tesla) charging at a services would consume over 6MW. Thats a lot of power.

Robert G8RPI
 
Roberts right, every third house on single phase, flats multi dwellings usually have 3 phase at entry point, but then down to single phase at individual consumer units. Hence not all the houses go out in the event of a fault/power cut, same will apply with street lighting depending on scale. The logistics behind upgrading the existing infrastructure to allow demand to be met must surely require another 20.....odd.....years of tech advance in charging systems not manual installation of a supply line based on today’s known s. I don’t see any of the EV spectrum for the masses yet despite what we are urged into, I think further advances will negate the needs for the massive upgrades to domestic properties only time will tell I guess.
 
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