Truck #1 (Nicad)


I’ve got the pack doing better. But now it’s raining. Anywhere from 0-10 mph I
can spin the tires right up in the rain! More testing on dry pavement will force
more current from the system. That will let me know how close to 100kw I am.

Some prototyping netted 91kw of output from my truck recently. The acceleration was unbelievable. That’s still an 80% improvement. The pack is sagging more than normal right now. So I’m correcting that as of now. I suspect that would be worth a few more kw. Looking forward to 100kw soon as the pack gets updated and the R & D progresses.

The data sheets say the factory igbt’s are rated at 400 amps. Almost there now. If I can keep the pack above 250vdc at 400 amps, then I’ll be at 100kw.

I have had an igbt/hv buss redesign going. Might have to put more priority into that since the factory igbt’s are nearly at their max current rating. Although for maybe only 10-15 seconds at a time, 400 amps may not be a threat to their longevity.

With the A123 prototype modules doing fine, a full pack would have such low impedance that 100kw would be easy to hit. Maybe too easy. Going to build about 12 more A123 modules soon.

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.

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