On Mon, 9 Jun 2008 05:02:42 -0500, firstname.lastname@example.org (Leonard Abbott)
That is what is called a "mild hybrid". At least one company that I know of
is offering just such a kit. It consists of an oversized alternator-looking
thing that replaces the standard alternator, some electronics and a small
battery pack. It adds about 20 HP, as I recall.
It charges the pack during normal operation, especially during braking, and
then feeds it back during acceleration. This is primarily a green-sounding
hotrod kit, designed to improve acceleration, though the ads try to wrap it in
the usual green BS.
I can't imagine it doing much to improve mileage. True hybrids gain
efficiency by operating the engine only when necessary and then under optimum
conditions. The Miller cycle engine in the Prius, for example, would be a
total dog in a conventional car. No low-end torque to speak of. That doesn't
matter in the hybrid, though, because that planetary gear set that combines
the electric and gas power acts effectively as an infinitely variable gearbox.
A mild hybrid, OTOH, still has the engine hard-geared to the road. It must
turn at the same speed for a given road speed as before. About all the
electric assist could do would be to add power to help overcome friction. Only
if that power is recovered during regenerative braking would it improve
efficiency and then it wouldn't be available for assisting acceleration. This
would take different programming from what the kit comes with.
Sorry, I don't recall the brand name of the kit. A little googling should
turn it up. Look for "mild hybrid" and "electric power assist"
My approach to a plug-in hybrid (PHEV) is a little different than the popular
one. First off, I'm not going to pay 25 grand for a car small enough to be a
roller skate (Prius) and end up with a car that I can't modify - too much
embedded proprietary software.
My approach is a pure EV with a generator onboard. This is a so-called series
hybrid while the Prius-style is a parallel hybrid. Parallel because the gas
and electric motors work in parallel.
A typical generator with a utility-type engine isn't terribly fuel efficient
(though I'll improve it by adding my homemade EFI) by itself. The key to
superb mileage is to size the batteries so that the generator is seldom used.
Almost an emergency "get home" system.
I've been using that system for years on my hotrod scooter. I built a small
trailer that I tow behind the scooter for trips to the store and whatnot. On
long trips that threaten to exceed the battery range, I set a small generator
on the scooter. If my E-meter shows that my batteries are at the limit of
discharge, I simply crank the generator, wait a few minutes for the batteries
to accumulate some charge and then go on my way.
The conversion that I'm working on now, to be an S-10 pickup truck (I get all
the EV parts in hand before I acquire the vehicle), there will be a generator
in the truck bed, probably based on a small water-cooled car engine. This
generator will be powerful enough to run the vehicle at moderate speed without
This architecture is probably LESS efficient than if the engine were driving
the vehicle directly. The key is not having to use it very much.
John De Armond
See my website for my current email address
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
There is room for all of God's creatures.... Right next to the mashed potatoes.
On Mon, 09 Jun 2008 20:47:16 +0100, Eeyore
And about the only thing PRACTICAL as an electric vehicle.
** Posted from http://www.teranews.com **
clare, at, snyder, dot, ontario, dot, canada wrote:
You mean large EVs (like electric SUVs) are a crazy idea ? I'd tend to agree,
although it does mean it's easier for them to fit more batteries. EXPENSIVE
so I wouldn't want to be around when it comes to replacement time !