I have heard much talk about the potential development of range extending
trailer applications in theory, but have not found anyone verifying the concept
by building a prototype.

Since I had an entire extra set, actually extra two sets, of EP NiFe 200 AH
batteries I wanted to give the RXT-B (range extending trailer - battery) a real
life test.  Of course, one should always start with the theoretical, so here is a bit
of data as I have been told.

The TEVan has a single-string 180v pack that consists of 30 200AH batteries
and weighs 1,650 lbs.  The vehicle has a total OEM weight of 5,000lbs and an
80 mile range.  By adding a RXT-B as a second, parallel string, one would
increase the overall vehicle weight by 1,650lbs.

What additional range would we be expected to achieve?  It is my
understanding that the mathematical equation would be as follows:  “from the
relation range [km] = capacity [kwh] x 250 / mass [kg] ^ 0.6I”  Therefore,
doubling the energy capacity while increasing weight by 33% gives a range
increase of X 1.68 or a 135 mile range.  Well, I would believe that a 135 mile
on a TEVan would be quite impressive.  So I am off to try the experiment.

The following photographs represent the project status from inception to
present, and although it is not yet completed, it is getting close.

Feel free to let me know what you think, or if you have any suggestions for
Battery Electric Vehicle
Range Extending Trailer - Battery
Powered by 30 6v nominal Nickle-Iron (NiFe) Edison batteries
I started with a
simple square
frame design and
five original
TeVan Nife  
battery boxes.

Picture 1 of 4
Picture 4 of 4
Picture 3 of 4
Picture 2 of 4
We then added
the individual
battery monitoring
wiring, and a dual
torsion axle
system.  Later the
dual axle system
was eliminated due
to turning
resistance issues.
Here we are about
50% complete.  
The tounge tool
box was added to
hold a GM EV1 LPI
charging system.  
The laptop
monitors and
reporgrams the

Here are a set of
all around
pictures with
Note the air pump
system for battery
cooling and
ventalization.  The
supply piping on the
right side of the
trailer pressurises
the battery boxes
from the forward air
supply under the
charging system.
Alternatively, the
left supply uses a
vacuum system to
pull the ventalated
air out the rear of
the trailer.
Each battery box
will eventually be
completely water
tight with the box
covers shown in the
initial pictures
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Here is a
close-up of the
rear pump which
is designed to
pull, in a vacuum,
from the left side
of the battery
This view shows
the end of the
pressure side, as
well as the rear
air pump again.
Another view
Inside the
charging box we
added two LEDs
to monitor high
voltage (bottom),
and charging
amperes (top).
Well, that's it for
now.  More data
will be added as
progress is made.

Hope you
enjoyed the info.
We have added
an old Selectria
DC/DC converter
to power the LPI
system.  The
DC/DC will also
supply the power
to operate the
ventalation system
and LED
Another view.