Interesting. I see they're claiming the battery will charge in minutes
rather than hours.
Say a typical car petrol tank holds 12 gallons. 1 gallon of petrol has
an energy equivalent of 33.4kWh
So a typical car petrol tank contains an energy equivalent of about
400kWh. If that were to be replaced by a battery storage system, which
was wanted to be recharged in say 5 minutes (one twelfth of an hour),
as is done now with a petrol filling system, that would require a
power input of 4800kW (400x12). At 1000 amps that would be 4800 volts
(assuming my logic and numbers are correct, which they may not be!).
I'd be interested to see the forecourt of the future!
But I imagine things would no longer be done that way. If those
batteries are truly reliable, then an exchange system would probably
be the way things would go. Or perhaps an induction system, where you
just drive in, position your car over an induction plate and let it
charge, with no electrical linkages at all.
On Tue, 14 Mar 2017 11:47:39 +0000 (GMT+00:00), jim <k> wrote:
Well, of course. That's what happens now, but the problem arises when
you want to drive further than the capacity of your battery will
allow, and you have to re-charge en route.
Car petrol engines around about 20% max, a bit more for diesel.
Probably triple that for electric cars, so by implication only half
the equivalent tank capacity needed. But that still leaves some pretty
hefty amps/volts needed for charging.
See https://www.fueleconomy.gov/feg/evtech.shtml for some numbers.
Surely, triple => one-third capacity needed?
If you add in that electric cars tend to have regenerative braking and
so on, it gets better still.
One way petrol engines score is that they use waste heat for warming the
Sorry to be pedantic. :)
Anyway, it seems that an electric car with a fully charged 100kWh
battery should be able to do much the same range as a petrol car on a
single tank. Glancing at Tesla, they are claiming about 300 mile range
for their cars with the biggest batteries. That would suit me fine, as 4
hours is my absolute maximum drive.
it's not that simple though, is it
if you were visiting me for the weekend there is nowhere you could recharge
your car when you arrive
so your battery has to be good for the round trip
(FTAOD I live on on of these "modern" estates where nobody has a drive and
everyone parks on the road. And I live on the second floor so running a
cable out of the window isn't practical either)
Yes, I agree with those figures. OK if you want to stop at a service
station and pop in for a coffee while you wait, but at busy times
there's often a queue for the normal petrol pumps, and they have a
fairly rapid turnover, so what it would be like with a twenty minute
wait I shudder to think.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.