1994 US Electricar Repair Blog by Mike

I needed a new transmitter pack for my old JR X347. I went to Fry’s and got a pack of 8 2750mah NIMh cells to replace the old 600mah nicad pack. I don’t fly anymore, but these packs are for testing Victor motor controllers that I rebuild for the Combat Robotics crowd. In a couple of weeks Combots will be at the San Mateo Fair Grounds again!!

Here are the first 2 cells getting spot welded together. I had no fixture so I used this block and some scotch tape. I cut up some .010″ nickel strips to spot weld the pack together. The settings on the welder worked fine for this thickness of nickel.

Fold them in half.

Push them together.

Now I’m spot welding pairs of cells together.

I added the next pairs of cells to spot weld.

Here is the finished JR X347 pack.

I took the old JR X347 cells found the dead one, added a good one to them and made this my Futaba AM transmitter pack. Note that the settings on the spot welder are lower. These nickel tabs are recycled from the old Futaba pack.

Here is the new cell being charged by itself to bring it up to the same 100% state of charge that the other cells are at.

I started a new blog about the repair of my, new to me, 1993 Cummins Dodge truck. It’s my first diesel.

A great finish for an electric vehicle that is 17 years old, against Tesla’s that have 250% more power!!!!! <-- Click here!!!

For a 40% power increase, the 70kw upgrade (up from 50kw), and the Dropout Modification from US Electricar.net were used in this US Electricar Prism!!!

In the first part of day 3 our hero in his Prism is holding up well in his class
and total. The Volt is now 2 places above him in total. But over half the
Tesla’s are still placing under him!!

http://www.zerorally.com/results-zerorally-class-through-vaalerbanen.pdf

http://www.zerorally.com/results-zerorally-total-through-vaalerbanen.pdf

I hope I can get some video of this hot rod in action.

http://www.zerorally.com/results-zerorally-total-day2.pdf

One of my customers has a 1994 Prism that he entered into an EV rally. A very
serious one. It’s only day 1 of 3, but the results are very promising. In his
class there are 9 cars. 8 of them Tesla’s. He is 3rd in his class today in a
freakin’ Prism! 6th overall in the rally. He beat 6 Tesla’s today!! Several
dozen cars entered. He’s also ahead of a Chevy Volt He has some of my
specially prepared high performance US Electricar hardware. Depending on what he reports back on drivability, I may bump him another 20 or 30kw. He might beat me to being the first to do tire smoking burnouts in a USE vehicle. I should be the first with a truck at least

His car does have a few issues. It faults over bumpy roads. It did it last year
too without my hardware. I suspect it’s his conversion to lithium created a
ground fault somewhere. I gave him the instructions on how to check for a ground
fault with the software. When he gets done racing we’ll see what he finds.

Finally, I get back to my racing roots!!

Here are Day 1 results. Look for Geo Prism.

The 312v (405v max) AC motor control system in my truck is very energy
efficient. It’s only 70kw right now. But it will be 90kw here shortly. It has
the capacity to handle way over 100kw.

I don’t have to cram very much of a pack into this vehicle to get excellent
range. If I put in a 160ah set of Thundersky cells, my range would be 256 miles.
But then I have to put up with all of the cold voltage sag as well as the sheer
volume that this pack would take up. Works for some, just not for me.

Speed is electronically limited to 72mph. That also assumes I leave the
transmission locked in 2nd gear. It’s a 5 speed manual with overdrive. Adding a
shifter makes the top speed math go to some insane top speed. Or as ACP does,
remove all of the unused spinning mass in the form of gears and syncros for yet
more of an increase in efficiency.

Something I keep forgetting to explain. The cells themselves will only weight
154lbs. They completely fit in well under 1/2 the battery box.

The 7.36 kwh pack I’m building will take my truck 36 miles at it’s current
efficiency of 200wh/mi at 4000lbs. My estimate of a 15% increase in efficiency
from losing 600 lbs, will put the range at 42 miles at 175wh/mi at 3400lbs. On
only 50 amps the truck goes 60mph. There is an owner of a truck just like mine
with a 19.2kwh Thundersky pack. He went 112 miles on a charge. That’s about 171
wh/mi. But his cells weigh 550 lbs. That’s 400 lbs more than my A123 cells. It’s
feasible that my truck could end up with a 50 miles range off of the tiny A123
pack. Since the camber on the front end was finally just now set to zero, there
could be some additional increase in efficiency. I have yet to block the grille
and add the coroplast to the chassis underside to clean up some of the
aerodynamics. Those are standard features on all ACP vehicles, old and new. All
I need for my driving requirements is 15 miles of range. With 36+ miles of range
my cycle life will be close to forever.

I will pick up some cobalt 18650 cells for spot welding and testing. After all,
since the safest chemistry available can currently be set on fire so easily, it
just makes sense to try them. Their smaller size would make for an even lighter
pack. It’s just takes some mechanical and thermal engineering to make this work.
It’s just not that difficult.

I wonder if the laser welder I used back in 80′s is available surplus somewhere?
I use to spot weld nickel ‘flags’ to stainless wire. Not unlike materials for
cell module construction.

Gasoline is $3.79/gal down the street! Wow! We’re on our way to $4/gal and it’s not even close to Memorial day. Oil today was down to 96.50/barrel. Man am I glad this truck runs. The timing for making the A123 modules is pretty good.

The truck turned over 23k miles tonight. So in 765 more miles I will have put 20k miles on the truck myself. Everyone of them without using a drop of gasoline.

I wonder if it’s even possible to spot weld aluminum with my spot welder? It is not as conductive as copper, but is far less expensive. Copper has at least tripled in the last couple of years. So I will start with trying to spot weld some aluminum foil from the kitchen and see how that goes. It’s cheap and easy to use for proving the concept, one way or the other. I will still be trying to spot weld braid as well.