Re: Some thoughts about AC (was: For you, AC drive fans)

[Lee Hart <leeahart@earthlink.net>]

>> Of course, regen can add about 10% to your range...
>> I got more than that increase when I was using a 2CM77 and 48 volts.
>> It takes practice to really get the most from a good regen system.

VanDerWal, Peter MSgt wrote:
> My BS meter just pegged.  50% range increase from regen?

Ah, but there are extenuating circumstances. My first EV had one of
these old aircraft starter-generators as a motor. Strangely enough, I
think I really did get a 50% range increase in extreme operating
conditions.

I had a heavy vehicle with only 72v worth of golf cart batteries. This
meant I was drawing 500-1000 amps under accelleration. Boy, do they sag
fast at that current! Without regen, the pack was effectively dead at
10-20 miles. It could no longer supply that kind of current (Peukert
effect). If the pack was more than about half discharged, you still had
the 100 amps or so it took to cruise, but not enough peak current to
acellerate with traffic.

With regen, the batteries got a quick 500-amp charge every time you
stopped (Boy, can aircraft generators do regen!). As a consequence, they
could supply a brief 500 amp surge when you accellerated again. The
vehicle still had enough accelleration to keep up with traffic even when
the pack was more than half discharged.

The amount of power saved by regen was probably only 10-20%. But you had
the power exactly when you needed it most; thus it extended the range
much more than 10-20%. 50% more range (15 miles instead of 10 miles) is
very likely; even 100% (20 miles instead of 10 miles) is possible.
--
Lee A. Hart                Ring the bells that still can ring
814 8th Ave. N.            Forget your perfect offering
Sartell, MN 56377 USA      There is a crack in everything
leeahart_at_earthlink.net  That's how the light gets in - Leonard Cohen