There are many reasons why I chose to place all the twelve batteries in one box in the cargo area of the van.
The most important one is that this way I can have a heater inside the box (lid is removed on the picture) and have all batteries at the same temperature and at a constant warm (usually around 20 degr C) temperature during the winter season. I have almost the same range during the winter as in the summer.
Another good reason is simplicity. There was no need for welding battery structures for the batteries under the hood. The total weight of the EV is distributed evenly on the front and rear tires. No changes was done to the structure of the car and thus there was now problems with this during vehicle inspection and approval.
Improvements for handling could have been done by lowering the
batteries under or through the floor (lot of welding and maybe
problems with approval later). Also, during the winter season
the front wheel drive EV might have had an advantage by moving
some of the weight further forward. But, all together I still
would have placed the batteries in the same place again. It also
allows for a lot of flexibility for possible future change to
other battery sizes or to higher voltages by adding batteries.
Or perhaps a generator to make a hybrid..? Back to top
The batteries are secured to the floor by 8 mm steal rods. Across the top of two or three batteries there is one steal beam inside a hose. The hose is of the type that is totally flat when not in use. It is soft and used as insulation. Underneath the batteries is a thin layer of insulation (about 10 mm). (It is actually my old camping mattress that I used when I was a boy scout about 20 years ago.Very yellow.) Under neith that is a 6 mm wood laying on the floor.
Under the floor, on the outside of the car, there is another steal beam in the same size as the one on the top of the batteries. The upper beam connects to the lower beam with the 8 mm steal rods. I feel confident that these batteries will not move in the event of a crash. In addition, I do also have the "steal fence" between the cargo area and my driving seat. Electric Vehicles of America specifies that the battery restraint system should be designed for 20 G front impact, 15 G side impact and 10 G rear and vertical impact.
Also, notice how nice and clean averything is with the sealed
Optima Yellow Tops. No acids and no corrosion. And I just love
that yellow color!
The american standard AWG #2/0 welding cable works out to be about 69 mm2 which is so close to the european standard of 70 mm2 that lugs can be used interchangeable. (Totally amazing!). So I crimped the american battery lugs to the 70 mm2 welding cable using this incredible hydraulic crimp tool. The tool ( about $1000 new) was rented from a shop that rents to powerline companies and electricians. It is very heavy and selfadjusting for sizes 50 to 90 mm2 .
Remove some insulation from the cable, put it into the lug and start pumping the two handles.
When the resistance in the handles all of a sudden dissapears, then the lug is done. Twist the turn knob at the end to remove the pressure, and the completed lug can be removed from the tool. On the picture above you can see where to aim when crimping ( from the side, like the bottom lug). If the crimp tool hit the lug from top or bottom (like the upper lug), the part of the battery lug that goes around the battery post would twist slightly, making it a little bit difficult to enter it to the battery post.
When doing the other end of the battery cable, do not forget to enter one red and one black battery terminal cover on to the cable. I did not use shrink tube on the battery lugs, because it would make it hard to fit the battery terminal covers. Every where else I did use shrink tubes. A smart idea would be to make a small hole in the top of each battery terminal cover. Large enough to enter the tips of the the probes of a DMM (voltmeter). This would make it easier to do voltage measurements on your battery pack. Back to top
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