You'd need more than that for your "city car" serial-sometimes-hybrid
to be practical, at least here in the YooEss. People expect a 4-500
mile range per "gas tank" of whatever sort. I don't see where you are
getting your figures from, however - let's do the numbers again.
Gasoline has about 700,000 BTU/gallon or 205 kWh/gal. a gallon weighs
8.3 lbs or 3.8 kg. So that's 53 kWh/kg. (wait, I screwed up something
somewhere before, because I just ran through it again and that number
seems different than I recall. But the point remains the same.)
So to get a 400 mile range out of an average ICE-powered car, you'd need
about 100 lbs or less of fuel. That contains as much energy as you'd
get from approximately 4,500 lbs. of your batteries.
Or to put it another way, that's what would be needed for the idea of
storing electricity on board to be as practical for the end user as
simply running an ICE. Of course, in the real world, assuming that this
magical energy density comes with the ability to charge and discharge
quickly, you'd actually see some additional benefit from regenerative
braking, but that would depend very heavily on maximum charge rate.
Or to put it a *third* way, since the Prius seems to be getting about
the same gas mileage as some comparable Diesel cars, there's really ZERO
advantage to all this extra complexity and monkey motion until we can
make a significant decrease in the weight of our batteries, and/or
dramatically increase their ability to take a fast charge to take
advantage of regenerative braking, or both. Because I dunno about you,
but when presented with two machines that are equally efficient, but one
is half as complex as the other, I'll take the simple one every time.
It's going to take a dramatic increase in gas mileage above and beyond
what I can get out of a well-tuned ICE to make me take the plunge.
No, no it won't. Not unless you enjoy driving something like an
overgrown golf cart.
replace "roosters" with "cox" to reply.
But everyday commuting *isn't* 500 miles.
All a hybrid needs is enough battery capacity to run its daily comuting run on
battery. Any more is wated capacity quite frankly. The idea obviously being to
off mains electricity at work, home or elsewhere.
The ICE only needs to kick in when a longer range is required and it'll happily
as many miles as you care to provide fuel for.
Sure, but that implies a) a breakthrough in battery technology that
hasn't happened yet (a serial hybrid isn't practical ATM because of
battery limitations) and b) a LOT more stored energy than you're
replace "roosters" with "cox" to reply.
I personally have probably logged 500 miles in a single day's work
before. Over the course of two days, quite often. Before I moved, it
was 50 miles from my house to my office. throw a couple job site
visits in and you're there.
I know that there are people that live in PA that commute back and
forth to Baltimore every day. People live where they can afford, and
work where they can get paid.
Things are changing already. Today. NOW !
" Electric vehicles:..................
Free recharging points are also available in 13 of our 17 car parks. "
FREE electricity too ! They really want to reduce pollution.
It implies no such things at all.
I suggest you calculate how much energy it takes to move a fairly normal size
car at say 80
mph. You might get a shock how little it is compared to the output of ICEs.
The equations for rolling resistance and air drag are readily available if you
That's why you can 'get way with' as little as 15kWh of stored energy.
The onboard ICE will also come in handy for winter heating too. It's nuts to use
the battery for space heating.
You're neglecting that you need a power reserve in an electric car
too. that means not only bigger, heavier motors than required for
steady state cruising, but extra battery capacity as well. I don't
know about the cutting edge technology batteries, but the sealed lead-
acid deals that I am familiar with don't like to be discharged at a
rate greater than their amp-hour rating, as a rule of thumb. (i.e. if
you have a 50Ah battery, you don't want to discharge it at a rate much
above 50A to prevent damage.) I would assume that similar limitations
are found with other batteries, although I don't know if they
correlate the same way or not.
You need those just to provide acceptable acceleration.
The power required for cruising at 70 mph is a mere 30 bhp (22kW).
22kW of motors will give you asthmatic acceleration and the car will slow down
on gradients so
you'd probably fit ~ 45kW of motors just to cope with those two things. It would
give you 0-60 in 9
seconds btw in a lightweight 1 tonne (2200 lb) body.
Fitting 45kW of motors won't increase the cruising power consumption or the
Lead-acid technology is over a century old and is not relevant to a discusion
The issue of charge and discharge rates is well understood. It's *NOT* rocket
Modern NiMH and Li-ion battries for high current applications address these
My calculations show 400 miles would need 125 kWh.A 125kWh battery *would* weigh
kg. But you never need 125kWh of battery storage.
You simply don't do those 400 mi on energy that was stored 'back at the ranch'.
Depending on the scenario you top-up daily with mains electricity or generate
as you drive when the battery starts to run 'dry'.
And yet, it's the best hybrid available from a major manufacturer
You can point to vaporware all you want, but the truth is, the Prius
is the most advanced hybrid vehicle that a major manufacturer
apparently feels comfortable putting on the market, for whatever
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