In article , NY
wrote:
"Andy Bennet" wrote in message
o.uk...
On 10/03/2018 15:12, ARW wrote:
On 10/03/2018 14:23, Dave Plowman (News) wrote:
In article , NY
wrote:
I wish electrics had advanced where they had the same 700 mile range

You'll actually drive 700 miles without a stop? Even at 70 mph, that
is 10 hours solid driving. Most would expect to stop at least once in
that time for a comfort break and likely a meal. So could re-fuel
then.

And if not doing a long journey silly to carry around a large amount
of fuel.


Do cars exist that will do 700 miles at 70MPH on one tank of fuel?

Cornwall and back without stopping (other to drop my friend off) is
something I do quite often. That's just over 700 miles round trip at
say 80 MPH.


Are you built like a camel or do you have an attachment connected to
your willy?

No-one said it was 700 miles non-stop. But it may be 700 miles with much
shorter breaks than you'd need to allow for refuelling an electric car.

A petrol or diesel pump adds energy to the car at a phenomenal rate.
Petrol and diesel are each about 35 MJ/litre
(https://en.wikipedia.org/wiki/Energy_density) so if you put in 60 litres
in 5 minutes. that's a rate of 35,000,000 * 60 / 300 J/sec (ie W), or 7
MW.

That''s a serious amount of electricity that you'd need to charge an
electric car with to equal it. Even if the charging process was 99%
efficient, that's still 70 kW of waste heat you've got to dispose of.

OK, it's not quite a fair comparison because electric motors are more
efficient than petrol/diesel engines so you wouldn't need to take onboard
as much energy. But it's still a lot of energy needed in a short period
of time.

You may only need to do 100 miles in a day, with all night (or many hours
during the day while you are at work) to recharge. But if you ever need
to do a longer journey, you may have to re-plan your day if you have to
factor in a recharge stop of maybe 6 hours somewhere in the day.
Swappable batteries would be one way, but cars tend not to be designed
with the batteries in an easy-to-remove tray and there's the age-old
problem of swapping clapped-out batteries that don't hold as much charge
for new ones which will hold more - I'm sure a comparable problem
existed several centuries ago when stage coaches swapped horses several
times on a journey: you may end up getting something much better (or
worse) that you had before (leaving aside the short-term problem of
tired horses that will be fine after a night's rest).

but who owned the stage coach horses?

--
from KT24 in Surrey, England