We are getting so close to the 7's, we can taste it. 
We all pitched in and managed to put the KillaCycle back together and
to build a newer, slightly larger, A123 Systems Nano-phosphate
battery pack in time for this race. Steve got the data logger up and
running for this race too. Whew! It was an intense few weeks.
Derek worked like the devil welding cells and soldering BMS modules.
The new pack is 110 in series by 11 in parallel to make a total of
1210 cells. We switched over to copper "bussbar" strips instead of
the standard nickel tabs. They are a bit more tricky to weld to the
cells, but they are lighter and conduct much better.
The addition of 220 cells put 34 more pounds on the bike. This
shifted our CG forward and down slightly. Because of that, we had to
find a new combination of launch current and throttle ramp rate to
make the bike transfer weight correctly on the launch. We kept
hopping or spinning the tire. In the end, we had Scotty run the bike
"seat-of-the-pants" on the manual throttle instead of using the
button to run the launch sequence.
With Scotty running the throttle, we managed to get the bike to hook
up decently (1.21 sec 60 ft) and we ran a 8.083 @159 MPH. We were
right at the end of our available track time, so we simply ran the
bike past the pits and directly to the starting line without
recharging or even cooling the controller. With a slightly warm
controller, the sixty foot time stretched out a touch to 1.22 seconds
and we didn't pull as hard on the front half, but the warmer
batteries made up for it in the back half to give us 8.083 seconds @ 163 MPH.
It was pretty nifty to demonstrate, on national TV, that the A123
Systems batteries can put out full power for multiple runs without
recharging. We really wowed these guys with these back-to-back
record-breaking runs.
Rich Rudman (bless his little heart) lent us a monster PFC-50 charger
for this race. We were grinning like the Cheshire cat when we were
able to recharge the bike, on camera, in 3 minutes, 36 seconds!
Again, we floored the TV crew when we were able to recharge in LESS
time than we predicted using LESS electricity than we predicted. We
LOVE this PFC-50 charger!
I suspect that the larger pack and the copper interconnects are
making our internal pack losses significantly lower. These lower
losses result in higher efficiency and naturally fewer Watt-hrs per
run. We managed to fill the pack back up to 375 volts (ready to run
again) with just 550 Watt-hrs, (~6 1/2 cents) of electricity.
You will see all of this on Discovery Channel "Mean Green Machines"
in January or February.
Bill Dube'
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
We all pitched in and managed to put the KillaCycle back together and
to build a newer, slightly larger, A123 Systems Nano-phosphate
battery pack in time for this race. Steve got the data logger up and
running for this race too. Whew! It was an intense few weeks.
Derek worked like the devil welding cells and soldering BMS modules.
The new pack is 110 in series by 11 in parallel to make a total of
1210 cells. We switched over to copper "bussbar" strips instead of
the standard nickel tabs. They are a bit more tricky to weld to the
cells, but they are lighter and conduct much better.
The addition of 220 cells put 34 more pounds on the bike. This
shifted our CG forward and down slightly. Because of that, we had to
find a new combination of launch current and throttle ramp rate to
make the bike transfer weight correctly on the launch. We kept
hopping or spinning the tire. In the end, we had Scotty run the bike
"seat-of-the-pants" on the manual throttle instead of using the
button to run the launch sequence.
With Scotty running the throttle, we managed to get the bike to hook
up decently (1.21 sec 60 ft) and we ran a 8.083 @159 MPH. We were
right at the end of our available track time, so we simply ran the
bike past the pits and directly to the starting line without
recharging or even cooling the controller. With a slightly warm
controller, the sixty foot time stretched out a touch to 1.22 seconds
and we didn't pull as hard on the front half, but the warmer
batteries made up for it in the back half to give us 8.083 seconds @ 163 MPH.
It was pretty nifty to demonstrate, on national TV, that the A123
Systems batteries can put out full power for multiple runs without
recharging. We really wowed these guys with these back-to-back
record-breaking runs.
Rich Rudman (bless his little heart) lent us a monster PFC-50 charger
for this race. We were grinning like the Cheshire cat when we were
able to recharge the bike, on camera, in 3 minutes, 36 seconds!
Again, we floored the TV crew when we were able to recharge in LESS
time than we predicted using LESS electricity than we predicted. We
LOVE this PFC-50 charger!
I suspect that the larger pack and the copper interconnects are
making our internal pack losses significantly lower. These lower
losses result in higher efficiency and naturally fewer Watt-hrs per
run. We managed to fill the pack back up to 375 volts (ready to run
again) with just 550 Watt-hrs, (~6 1/2 cents) of electricity.
You will see all of this on Discovery Channel "Mean Green Machines"
in January or February.
Bill Dube'
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
