1993 tevan RXT-B

-- Beata Collection --




RXT-G

Powered by 30 6v nominal Nickle-Iron (NiFe)
Edison batteries mirroring the original
TEVan traction pack.

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We have heard (c2005) 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 we had an entire extra set of EP NiFe 200 AH batteries
we decided 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 to share.

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

The question is what additional range would we be expected
to achieve with the second string?
The math 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.  135 miles on a TEVan would  be
impressive.  So we are off to try the experiment.

The following photographs represent the project status
from inception to present, c2005, and although it is not
yet completed, it is getting close.


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--->  Additional pictures below  <---

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We started with a simple square frame design and five original TEVan Nife battery boxes.

In the original TEVan configuration one of these six (6) module battery boxes would be two (2) three (3) module boxes. The design was better served to employ five (5) same for same boxes.

We added the individual battery monitoring wiring, and a dual torsion axle suspension system. Later the dual axle system was eliminated due to turning resistance issues, although the weight distribution improvements were of interest.

Here we are about 50% complete. The tongue tool box was added to hold a GM EV1 LPI charging system. The laptop monitors and re-porgrams the charger. The tool box in wood was only intended to be a proof-of-concept piece, and could not have been used in any weather with HV.

Note the air pump system for battery cooling and ventilation. The supply piping on the right side of the trailer pressurizes the battery boxes from the forward air supply under the charging system.

Alternatively, the left supply uses a vacuum system to pull the ventilated air out the rear of the trailer.

Each battery box will eventually be water tight with the box covers shown in the initial pictures above in the same manor as the original traction pack in the TEVan.

Here is a close-up of the rear pump which pulls, in a vacuum, from the left side of the battery trays.

This view shows the end of the pressure side, as well as the rear air pump again.

We added a Selectra DC/DC converter to power the LPI system. The DC/DC will also supply the power to operate the ventilation system and LED monitoring systems.

Inside the charging box we added two LEDs to monitor high voltage (bottom), and charging amps (top).