Re: Can this be true? -and- Gizmo Range

["1sclunn" <1sclunn@msn.com>]

I have been think about the "50% rule of thumb" and wonder if size or scale
plays a part as the smaller or lighter the car the less range appears.
example to the extreme take the RC cars which may have a 50/50 weight  but
wont go 10 miles .

----- Original Message -----
From: "Peter VanDerWal" <peterv@peoplepc.com>
To: <ev@listproc.sjsu.edu>
Sent: Friday, June 28, 2002 6:16 PM
Subject: Re: Can this be true? -and- Gizmo Range


> > Well then 150 miles.  I was trying to make a point.  I may be ignorant
of
> > changes made to the Gizmo.  As I remember the hood popped up and you
> stepped
> > in.  It had very skinny tires and I can't figure out where the batteries
> > would go unless it has been redesigned.  Thanks for the update.  40
miles
> > and using only 20% of the pack sounds like the pack would last a long
> time.
>
> I said 80% DOD (Depth of Discharge) that means using 80% of the charge not
> 20%.
>
> The gizmo with the thick tires weighs 340 lbs.  The batteries weigh 520
lbs.
> With a 180 lb.  driver that is 50/50 batteries/Vehicle driver weight.
> Vehicles with this kind of ratio(Red Beastie/FiatX19) are capable of well
> over100 miles on a charge.  Is the Gizmos gear ratio a problem for it to
> attain higher range.  If it were geared to only go 25mph would its range
> improve as well as hill climbing?  Why do the larger vehicles get better
> range.  A Parcar/Lynch with eight batteries gets over 100 miles range.
> Lawrence Rhodes.....
>
> > The gizmo with the thick tires weighs 340 lbs.  The batteries weigh 520
> lbs.
> > With a 180 lb.  driver that is 50/50 batteries/Vehicle driver weight.
> > Vehicles with this kind of ratio(Red Beastie/FiatX19) are capable of
well
> > over100 miles on a charge.  Is the Gizmos gear ratio a problem for it to
> > attain higher range.  If it were geared to only go 25mph would its range
> > improve as well as hill climbing?  Why do the larger vehicles get better
> > range.  A Parcar/Lynch with eight batteries gets over 100 miles range.
>
> 8 T-105s weigh about 488 lbs but I'll grant you that 180lbs is a more
> reasonable figure for a driver than my 260 lbs.
>
> Also the 50% rule of thumb is:
> A) a rule of thumb -not- a hard and fast rule.
> B) intended for full size EVs, not -every- EV.
>
> The weight of a vehicle is not the predominate factor when figuring energy
> requirements, at least not on reasonably flat ground at high speeds (>20
> mph).  Aero dymamic drag is a more important factor at high speeds, the
> higher the speed the more important.
>
> The Gizmo appears to have really awful aerodynamics.  I'd be willing to
bet
> that it has a similar CdA to some small, sleek production automobiles.  On
> the other hand it has very narror tires (which possibly helps rolling
> resistance) and is very light (which also helps).
>
> It seems reasonable to estimate that it requires slightly less than 1/2
the
> energy compared to a full size EV.  But then it's carying less than 1/2
the
> batteries of a typical EV.  Net result is approx the same range as a
typical
> EV.
>
>