[ausev] AusEV Digest, Vol 37, Issue 8

[Brian Lasseter]

On Tue, Feb 10, 2009 at 7:55 AM, William Gooch <goochb at alum.mit.edu> wrote:
> There's also the option of using the secondary shaft on my traction motor to
> drive the AC compressor using a belt and pulleys, much as the ICE motor
> did.  I realize this has some drawbacks, but it would be cheaper and perhaps
> less trouble than adding a separate new compressor setup.  I wonder whether
> it might also draw less power from the battery pack.  What experience do
> folks have with this?  Thanks.


The laws of physics are quite clear on this point... you will draw
more power from the battery pack if you try to run the A/C off of a
secondary shaft from the traction motor due to mechanical and friction
losses.  It is most efficient for the A/C to have it's own motor
running at that motor's most efficient speed.   (This is why some
newer luxury sedans are moving to all electric air conditioning too...
it allows them to eek out a few more MPG for the gov't ratings.)

(Besides... it very fun to be able to turn on cold A/C in a parked car.)


TTFN,
Brian "Lasso" Lasseter

"No Sane man will dance."   -Cicero (106-43 B.C.)