You will not regret it. Just another small point in oversizing the cable means a smaller voltage drop and so less losses in the cable. So even a
13A sustained load (future small EV charging point) will make savings over time.
Overnight EV charging is very low current. My EV charger is only 10 Amps.
That's because you have car with the battery capacity comparable to a bulk pack of AAs from Poundland.
Most dedicated chargers (i.e. hard wired rather than plug in) will draw 6kW.
A Tesla with its more practical 130kWh battery would take more than two and a half full days to charge at the charge rate delivered with your charger.
How many people here will be buying a Tesla? How many people people will run it to depletion? The answer is none of them. Most will run it nowhere near depletion.
95% of people use their EV for commuting and will be able to charge their car overnight from a 13a socket. EVs mostly have batteries of 25Kwh or less.You really are a s**te for brains. A Kwh takes most EVs four to five miles due to regeneration and much higher efficiency.
Lets look at that..
25kW for motor running a car at about 35-40mph. So five miles will use about 8 minutes at 25kW. That is about 3.4 kWHr.If you run at motorway speeds that will easily be twice that.
There is no recovery from braking unless you are stuck in a queue.
If you commute is less than five miles you may as well use a bike.
When you start calling John Rumm stupid we know you have lost it!
In the future? I don't know, and neither do you. However the point stands, that before EVs can become mainstream, they need more battery capacity. Something that can do a real 250+ miles in all weathers and conditions is going to be a realistic minimum for most buyers.
Very few - which increases the required capacity.
Logic is not your thing is it?
And hence will need larger rather than smaller batteries, unless you also have a plan to move the places they frequent closer together?
Yup they can charge it - a little bit.
The older toy ones yes. Newer models are getting a bit more practical:
2018 Tesla Model S 100D ? 100 kWh. 2018 Tesla Model X 100D ? 100 kWh. 2018 Tesla Model 3 Long Range ? 80.5 kWh. 2018 Chevy Bolt ? 60 kWh. 2018 Nissan LEAF ? 40 kWh. 2017 Volkswagen e-Golf ? 35.8 kWh. 2018 Ford Focus Electric ? 33.5 kWh.And most of those could use significantly more...
From you, I take that as a compliment.
Also there has been problems with battery degradation with the new batteries,
There already too many cyclists on the road.
So basically EVs are shit then?
====snip====
More like 2 to 5 KW at a steady 35 to 40mph on the level...
Assume 5KW consumption and 35mph. That's 8.57 minutes which works out to some 0.7KWH's worth of energy from the battery.
Only if you were referring to the energy consumed per unit distance. If you assume a steady 70mph versus the 35mph, you will need at least four times the power (double the rpm with at least double the torque to overcome the doubled up aerodynamic drag forces). Four times the power in half the time represents twice as much energy (KWHs) per unit distance.
I've assumed low Reynolds numbers here (35 to 70 mph speed range). At high Reynolds numbers (150mph and faster?), the power required to overcome aerodynamic drag eventually transitions to the cube of the speed.
That makes no sense.
That rather depends on the nature of the journey and the fitness of the commuter. For someone in good health with no need to carry excess baggage, that can be a very cost effective way to justify the consumption of an extra Mars Bar or two without the risk of joining the ranks of the morbidly obese.
However of course, this mode of travel has a higher micromort rating than that of travelling by private car, you just might end up a skinny dead person with more willing coffin bearers at your funeral. :-(
You haven't allowed for energy recovery by regeneration. But going fast is not good. Definitely not motorways. Low ambient temperature reduces range (affects batteries). Some cars have heat pumps for cab heating.
Yes I have, there isn't any unless you keep slowing and stopping. Then it takes more to accelerate back to speed.
What there is is seriously exaggerated by greens too.
For steady state driving, there will be very limited scope to recover anything. The best you can hope to recover is a proportion of the KE represented by the momentum of the car. However the vast bulk of the losses on a motorway trip will be overcoming drag losses, and those are not recoverable.
Perhaps from the prospect of a doddery pensioner.
Again, not optional in many cases.
Only drive in summer?
The better ones also have complete pumped thermal management systems for the batteries to keep them within temperature spec. Needless to say that also consumes additional power.
You've obviously played with this more than me - but I was under the impression that flow over a car was turbulent, and that the drag was proportional to the square of the speed at normal speeds. Which means power proportional to speed cubed.
A quick google supports that view - so are you sure?
Andy
I'm pretty sure it depends on the Reynolds number which varies according the CD ratio and speed. Unfortunately, I couldn't find any examples to indicate at what speed aerodynamic drag for a modern road car typically starts transitioning from doubling to quadrupling with speed (power demand going from the square of the speed to the cube of the speed).
How would you know? Obviously there are no hills where you live.
What part of "steady 70 mph on a motorway" do you fail to understand?
Even if there are hills, all that will change is an increase in power required when going up, and a reduction when coming down. At 70 mph you will require power output at all times to maintain the speed even going downhill, so there will be nothing to recover.
There are no steep hills on motorways. The regenerative braking is adjustable. Set according to terrain an bends in road.
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